2005-04-16 15:20:36 -07:00
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2012-05-14 08:29:23 +02:00
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2007-09-21 09:19:54 +02:00
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2005-04-16 15:20:36 -07:00
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blk-mq: new multi-queue block IO queueing mechanism
Linux currently has two models for block devices:
- The classic request_fn based approach, where drivers use struct
request units for IO. The block layer provides various helper
functionalities to let drivers share code, things like tag
management, timeout handling, queueing, etc.
- The "stacked" approach, where a driver squeezes in between the
block layer and IO submitter. Since this bypasses the IO stack,
driver generally have to manage everything themselves.
With drivers being written for new high IOPS devices, the classic
request_fn based driver doesn't work well enough. The design dates
back to when both SMP and high IOPS was rare. It has problems with
scaling to bigger machines, and runs into scaling issues even on
smaller machines when you have IOPS in the hundreds of thousands
per device.
The stacked approach is then most often selected as the model
for the driver. But this means that everybody has to re-invent
everything, and along with that we get all the problems again
that the shared approach solved.
This commit introduces blk-mq, block multi queue support. The
design is centered around per-cpu queues for queueing IO, which
then funnel down into x number of hardware submission queues.
We might have a 1:1 mapping between the two, or it might be
an N:M mapping. That all depends on what the hardware supports.
blk-mq provides various helper functions, which include:
- Scalable support for request tagging. Most devices need to
be able to uniquely identify a request both in the driver and
to the hardware. The tagging uses per-cpu caches for freed
tags, to enable cache hot reuse.
- Timeout handling without tracking request on a per-device
basis. Basically the driver should be able to get a notification,
if a request happens to fail.
- Optional support for non 1:1 mappings between issue and
submission queues. blk-mq can redirect IO completions to the
desired location.
- Support for per-request payloads. Drivers almost always need
to associate a request structure with some driver private
command structure. Drivers can tell blk-mq this at init time,
and then any request handed to the driver will have the
required size of memory associated with it.
- Support for merging of IO, and plugging. The stacked model
gets neither of these. Even for high IOPS devices, merging
sequential IO reduces per-command overhead and thus
increases bandwidth.
For now, this is provided as a potential 3rd queueing model, with
the hope being that, as it matures, it can replace both the classic
and stacked model. That would get us back to having just 1 real
model for block devices, leaving the stacked approach to dm/md
devices (as it was originally intended).
Contributions in this patch from the following people:
Shaohua Li <shli@fusionio.com>
Alexander Gordeev <agordeev@redhat.com>
Christoph Hellwig <hch@infradead.org>
Mike Christie <michaelc@cs.wisc.edu>
Matias Bjorling <m@bjorling.me>
Jeff Moyer <jmoyer@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-24 09:20:05 +01:00
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2005-04-16 15:20:36 -07:00
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2008-09-11 10:57:55 +02:00
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2007-07-09 12:40:35 +02:00
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2008-09-13 20:26:01 +02:00
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2013-01-09 08:05:13 -08:00
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2005-04-16 15:20:36 -07:00
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2011-05-26 13:46:22 -04:00
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2006-03-22 17:52:04 +01:00
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2005-04-16 15:20:36 -07:00
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2006-03-23 20:00:26 +01:00
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2007-07-09 12:38:05 +02:00
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2011-07-31 22:05:09 +02:00
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2012-04-16 13:57:25 -07:00
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2005-04-16 15:20:36 -07:00
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2012-04-13 13:11:28 -07:00
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2005-04-16 15:20:36 -07:00
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2006-01-06 09:49:03 +01:00
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2005-04-16 15:20:36 -07:00
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2012-06-04 20:40:59 -07:00
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2005-04-16 15:20:36 -07:00
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2012-06-04 20:40:59 -07:00
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blkcg: implement per-blkg request allocation
Currently, request_queue has one request_list to allocate requests
from regardless of blkcg of the IO being issued. When the unified
request pool is used up, cfq proportional IO limits become meaningless
- whoever grabs the next request being freed wins the race regardless
of the configured weights.
This can be easily demonstrated by creating a blkio cgroup w/ very low
weight, put a program which can issue a lot of random direct IOs there
and running a sequential IO from a different cgroup. As soon as the
request pool is used up, the sequential IO bandwidth crashes.
This patch implements per-blkg request_list. Each blkg has its own
request_list and any IO allocates its request from the matching blkg
making blkcgs completely isolated in terms of request allocation.
* Root blkcg uses the request_list embedded in each request_queue,
which was renamed to @q->root_rl from @q->rq. While making blkcg rl
handling a bit harier, this enables avoiding most overhead for root
blkcg.
* Queue fullness is properly per request_list but bdi isn't blkcg
aware yet, so congestion state currently just follows the root
blkcg. As writeback isn't aware of blkcg yet, this works okay for
async congestion but readahead may get the wrong signals. It's
better than blkcg completely collapsing with shared request_list but
needs to be improved with future changes.
* After this change, each block cgroup gets a full request pool making
resource consumption of each cgroup higher. This makes allowing
non-root users to create cgroups less desirable; however, note that
allowing non-root users to directly manage cgroups is already
severely broken regardless of this patch - each block cgroup
consumes kernel memory and skews IO weight (IO weights are not
hierarchical).
v2: queue-sysfs.txt updated and patch description udpated as suggested
by Vivek.
v3: blk_get_rl() wasn't checking error return from
blkg_lookup_create() and may cause oops on lookup failure. Fix it
by falling back to root_rl on blkg lookup failures. This problem
was spotted by Rakesh Iyer <rni@google.com>.
v4: Updated to accomodate 458f27a982 "block: Avoid missed wakeup in
request waitqueue". blk_drain_queue() now wakes up waiters on all
blkg->rl on the target queue.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-06-26 15:05:44 -07:00
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2009-04-06 14:48:01 +02:00
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2012-06-04 20:40:58 -07:00
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2012-06-04 20:40:59 -07:00
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2005-04-16 15:20:36 -07:00
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2006-08-10 08:44:47 +02:00
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2006-10-12 15:08:45 +02:00
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2006-08-10 08:44:47 +02:00
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2005-04-16 15:20:36 -07:00
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2014-05-06 12:12:45 +02:00
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2005-04-16 15:20:36 -07:00
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2014-01-30 15:45:47 -08:00
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blk-mq: new multi-queue block IO queueing mechanism
Linux currently has two models for block devices:
- The classic request_fn based approach, where drivers use struct
request units for IO. The block layer provides various helper
functionalities to let drivers share code, things like tag
management, timeout handling, queueing, etc.
- The "stacked" approach, where a driver squeezes in between the
block layer and IO submitter. Since this bypasses the IO stack,
driver generally have to manage everything themselves.
With drivers being written for new high IOPS devices, the classic
request_fn based driver doesn't work well enough. The design dates
back to when both SMP and high IOPS was rare. It has problems with
scaling to bigger machines, and runs into scaling issues even on
smaller machines when you have IOPS in the hundreds of thousands
per device.
The stacked approach is then most often selected as the model
for the driver. But this means that everybody has to re-invent
everything, and along with that we get all the problems again
that the shared approach solved.
This commit introduces blk-mq, block multi queue support. The
design is centered around per-cpu queues for queueing IO, which
then funnel down into x number of hardware submission queues.
We might have a 1:1 mapping between the two, or it might be
an N:M mapping. That all depends on what the hardware supports.
blk-mq provides various helper functions, which include:
- Scalable support for request tagging. Most devices need to
be able to uniquely identify a request both in the driver and
to the hardware. The tagging uses per-cpu caches for freed
tags, to enable cache hot reuse.
- Timeout handling without tracking request on a per-device
basis. Basically the driver should be able to get a notification,
if a request happens to fail.
- Optional support for non 1:1 mappings between issue and
submission queues. blk-mq can redirect IO completions to the
desired location.
- Support for per-request payloads. Drivers almost always need
to associate a request structure with some driver private
command structure. Drivers can tell blk-mq this at init time,
and then any request handed to the driver will have the
required size of memory associated with it.
- Support for merging of IO, and plugging. The stacked model
gets neither of these. Even for high IOPS devices, merging
sequential IO reduces per-command overhead and thus
increases bandwidth.
For now, this is provided as a potential 3rd queueing model, with
the hope being that, as it matures, it can replace both the classic
and stacked model. That would get us back to having just 1 real
model for block devices, leaving the stacked approach to dm/md
devices (as it was originally intended).
Contributions in this patch from the following people:
Shaohua Li <shli@fusionio.com>
Alexander Gordeev <agordeev@redhat.com>
Christoph Hellwig <hch@infradead.org>
Mike Christie <michaelc@cs.wisc.edu>
Matias Bjorling <m@bjorling.me>
Jeff Moyer <jmoyer@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-24 09:20:05 +01:00
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2014-02-24 16:39:52 +01:00
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|
|
|
blk-mq: new multi-queue block IO queueing mechanism
Linux currently has two models for block devices:
- The classic request_fn based approach, where drivers use struct
request units for IO. The block layer provides various helper
functionalities to let drivers share code, things like tag
management, timeout handling, queueing, etc.
- The "stacked" approach, where a driver squeezes in between the
block layer and IO submitter. Since this bypasses the IO stack,
driver generally have to manage everything themselves.
With drivers being written for new high IOPS devices, the classic
request_fn based driver doesn't work well enough. The design dates
back to when both SMP and high IOPS was rare. It has problems with
scaling to bigger machines, and runs into scaling issues even on
smaller machines when you have IOPS in the hundreds of thousands
per device.
The stacked approach is then most often selected as the model
for the driver. But this means that everybody has to re-invent
everything, and along with that we get all the problems again
that the shared approach solved.
This commit introduces blk-mq, block multi queue support. The
design is centered around per-cpu queues for queueing IO, which
then funnel down into x number of hardware submission queues.
We might have a 1:1 mapping between the two, or it might be
an N:M mapping. That all depends on what the hardware supports.
blk-mq provides various helper functions, which include:
- Scalable support for request tagging. Most devices need to
be able to uniquely identify a request both in the driver and
to the hardware. The tagging uses per-cpu caches for freed
tags, to enable cache hot reuse.
- Timeout handling without tracking request on a per-device
basis. Basically the driver should be able to get a notification,
if a request happens to fail.
- Optional support for non 1:1 mappings between issue and
submission queues. blk-mq can redirect IO completions to the
desired location.
- Support for per-request payloads. Drivers almost always need
to associate a request structure with some driver private
command structure. Drivers can tell blk-mq this at init time,
and then any request handed to the driver will have the
required size of memory associated with it.
- Support for merging of IO, and plugging. The stacked model
gets neither of these. Even for high IOPS devices, merging
sequential IO reduces per-command overhead and thus
increases bandwidth.
For now, this is provided as a potential 3rd queueing model, with
the hope being that, as it matures, it can replace both the classic
and stacked model. That would get us back to having just 1 real
model for block devices, leaving the stacked approach to dm/md
devices (as it was originally intended).
Contributions in this patch from the following people:
Shaohua Li <shli@fusionio.com>
Alexander Gordeev <agordeev@redhat.com>
Christoph Hellwig <hch@infradead.org>
Mike Christie <michaelc@cs.wisc.edu>
Matias Bjorling <m@bjorling.me>
Jeff Moyer <jmoyer@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-24 09:20:05 +01:00
|
|
|
|
2006-01-09 16:02:34 +01:00
|
|
|
|
2007-07-24 09:28:11 +02:00
|
|
|
|
blk-mq: new multi-queue block IO queueing mechanism
Linux currently has two models for block devices:
- The classic request_fn based approach, where drivers use struct
request units for IO. The block layer provides various helper
functionalities to let drivers share code, things like tag
management, timeout handling, queueing, etc.
- The "stacked" approach, where a driver squeezes in between the
block layer and IO submitter. Since this bypasses the IO stack,
driver generally have to manage everything themselves.
With drivers being written for new high IOPS devices, the classic
request_fn based driver doesn't work well enough. The design dates
back to when both SMP and high IOPS was rare. It has problems with
scaling to bigger machines, and runs into scaling issues even on
smaller machines when you have IOPS in the hundreds of thousands
per device.
The stacked approach is then most often selected as the model
for the driver. But this means that everybody has to re-invent
everything, and along with that we get all the problems again
that the shared approach solved.
This commit introduces blk-mq, block multi queue support. The
design is centered around per-cpu queues for queueing IO, which
then funnel down into x number of hardware submission queues.
We might have a 1:1 mapping between the two, or it might be
an N:M mapping. That all depends on what the hardware supports.
blk-mq provides various helper functions, which include:
- Scalable support for request tagging. Most devices need to
be able to uniquely identify a request both in the driver and
to the hardware. The tagging uses per-cpu caches for freed
tags, to enable cache hot reuse.
- Timeout handling without tracking request on a per-device
basis. Basically the driver should be able to get a notification,
if a request happens to fail.
- Optional support for non 1:1 mappings between issue and
submission queues. blk-mq can redirect IO completions to the
desired location.
- Support for per-request payloads. Drivers almost always need
to associate a request structure with some driver private
command structure. Drivers can tell blk-mq this at init time,
and then any request handed to the driver will have the
required size of memory associated with it.
- Support for merging of IO, and plugging. The stacked model
gets neither of these. Even for high IOPS devices, merging
sequential IO reduces per-command overhead and thus
increases bandwidth.
For now, this is provided as a potential 3rd queueing model, with
the hope being that, as it matures, it can replace both the classic
and stacked model. That would get us back to having just 1 real
model for block devices, leaving the stacked approach to dm/md
devices (as it was originally intended).
Contributions in this patch from the following people:
Shaohua Li <shli@fusionio.com>
Alexander Gordeev <agordeev@redhat.com>
Christoph Hellwig <hch@infradead.org>
Mike Christie <michaelc@cs.wisc.edu>
Matias Bjorling <m@bjorling.me>
Jeff Moyer <jmoyer@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-24 09:20:05 +01:00
|
|
|
|
2006-08-10 09:00:21 +02:00
|
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|
|
2013-05-23 12:25:08 +02:00
|
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|
2006-08-10 08:44:47 +02:00
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|
2008-09-14 05:55:09 -07:00
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2005-04-16 15:20:36 -07:00
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|
2010-03-19 08:58:16 +01:00
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2009-05-07 22:24:44 +09:00
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2010-03-19 08:58:16 +01:00
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2005-04-16 15:20:36 -07:00
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2014-04-09 20:27:01 -06:00
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2006-08-10 09:00:21 +02:00
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2011-02-11 11:08:00 +01:00
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2006-08-10 09:00:21 +02:00
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2011-02-11 11:08:00 +01:00
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2006-08-10 09:00:21 +02:00
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2006-07-28 09:23:08 +02:00
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2006-07-12 14:04:37 +02:00
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2010-04-21 17:44:16 +02:00
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2011-02-11 11:08:00 +01:00
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2011-12-14 00:33:41 +01:00
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2006-07-12 14:04:37 +02:00
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2011-02-11 11:08:00 +01:00
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2011-12-14 00:33:41 +01:00
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2011-02-11 11:08:00 +01:00
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block: fix flush machinery for stacking drivers with differring flush flags
Commit ae1b1539622fb46e51b4d13b3f9e5f4c713f86ae, block: reimplement
FLUSH/FUA to support merge, introduced a performance regression when
running any sort of fsyncing workload using dm-multipath and certain
storage (in our case, an HP EVA). The test I ran was fs_mark, and it
dropped from ~800 files/sec on ext4 to ~100 files/sec. It turns out
that dm-multipath always advertised flush+fua support, and passed
commands on down the stack, where those flags used to get stripped off.
The above commit changed that behavior:
static inline struct request *__elv_next_request(struct request_queue *q)
{
struct request *rq;
while (1) {
- while (!list_empty(&q->queue_head)) {
+ if (!list_empty(&q->queue_head)) {
rq = list_entry_rq(q->queue_head.next);
- if (!(rq->cmd_flags & (REQ_FLUSH | REQ_FUA)) ||
- (rq->cmd_flags & REQ_FLUSH_SEQ))
- return rq;
- rq = blk_do_flush(q, rq);
- if (rq)
- return rq;
+ return rq;
}
Note that previously, a command would come in here, have
REQ_FLUSH|REQ_FUA set, and then get handed off to blk_do_flush:
struct request *blk_do_flush(struct request_queue *q, struct request *rq)
{
unsigned int fflags = q->flush_flags; /* may change, cache it */
bool has_flush = fflags & REQ_FLUSH, has_fua = fflags & REQ_FUA;
bool do_preflush = has_flush && (rq->cmd_flags & REQ_FLUSH);
bool do_postflush = has_flush && !has_fua && (rq->cmd_flags &
REQ_FUA);
unsigned skip = 0;
...
if (blk_rq_sectors(rq) && !do_preflush && !do_postflush) {
rq->cmd_flags &= ~REQ_FLUSH;
if (!has_fua)
rq->cmd_flags &= ~REQ_FUA;
return rq;
}
So, the flush machinery was bypassed in such cases (q->flush_flags == 0
&& rq->cmd_flags & (REQ_FLUSH|REQ_FUA)).
Now, however, we don't get into the flush machinery at all. Instead,
__elv_next_request just hands a request with flush and fua bits set to
the scsi_request_fn, even if the underlying request_queue does not
support flush or fua.
The agreed upon approach is to fix the flush machinery to allow
stacking. While this isn't used in practice (since there is only one
request-based dm target, and that target will now reflect the flush
flags of the underlying device), it does future-proof the solution, and
make it function as designed.
In order to make this work, I had to add a field to the struct request,
inside the flush structure (to store the original req->end_io). Shaohua
had suggested overloading the union with rb_node and completion_data,
but the completion data is used by device mapper and can also be used by
other drivers. So, I didn't see a way around the additional field.
I tested this patch on an HP EVA with both ext4 and xfs, and it recovers
the lost performance. Comments and other testers, as always, are
appreciated.
Cheers,
Jeff
Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-08-15 21:37:25 +02:00
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2011-02-11 11:08:00 +01:00
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2006-07-12 14:04:37 +02:00
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2006-06-13 09:02:34 +02:00
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2011-01-05 16:57:38 +01:00
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2005-04-16 15:20:36 -07:00
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2010-04-01 15:01:41 -07:00
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|
blkcg: implement per-blkg request allocation
Currently, request_queue has one request_list to allocate requests
from regardless of blkcg of the IO being issued. When the unified
request pool is used up, cfq proportional IO limits become meaningless
- whoever grabs the next request being freed wins the race regardless
of the configured weights.
This can be easily demonstrated by creating a blkio cgroup w/ very low
weight, put a program which can issue a lot of random direct IOs there
and running a sequential IO from a different cgroup. As soon as the
request pool is used up, the sequential IO bandwidth crashes.
This patch implements per-blkg request_list. Each blkg has its own
request_list and any IO allocates its request from the matching blkg
making blkcgs completely isolated in terms of request allocation.
* Root blkcg uses the request_list embedded in each request_queue,
which was renamed to @q->root_rl from @q->rq. While making blkcg rl
handling a bit harier, this enables avoiding most overhead for root
blkcg.
* Queue fullness is properly per request_list but bdi isn't blkcg
aware yet, so congestion state currently just follows the root
blkcg. As writeback isn't aware of blkcg yet, this works okay for
async congestion but readahead may get the wrong signals. It's
better than blkcg completely collapsing with shared request_list but
needs to be improved with future changes.
* After this change, each block cgroup gets a full request pool making
resource consumption of each cgroup higher. This makes allowing
non-root users to create cgroups less desirable; however, note that
allowing non-root users to directly manage cgroups is already
severely broken regardless of this patch - each block cgroup
consumes kernel memory and skews IO weight (IO weights are not
hierarchical).
v2: queue-sysfs.txt updated and patch description udpated as suggested
by Vivek.
v3: blk_get_rl() wasn't checking error return from
blkg_lookup_create() and may cause oops on lookup failure. Fix it
by falling back to root_rl on blkg lookup failures. This problem
was spotted by Rakesh Iyer <rni@google.com>.
v4: Updated to accomodate 458f27a982 "block: Avoid missed wakeup in
request waitqueue". blk_drain_queue() now wakes up waiters on all
blkg->rl on the target queue.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-06-26 15:05:44 -07:00
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2010-04-01 15:01:41 -07:00
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2005-04-16 15:20:36 -07:00
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2010-09-10 20:50:10 +02:00
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2005-04-16 15:20:36 -07:00
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2006-06-13 09:02:34 +02:00
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2009-04-23 11:05:20 +09:00
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2005-04-16 15:20:36 -07:00
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2006-07-28 09:32:07 +02:00
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2005-04-16 15:20:36 -07:00
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2008-04-29 09:54:39 +02:00
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2010-03-19 08:58:16 +01:00
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2005-04-16 15:20:36 -07:00
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2008-03-04 11:17:11 +01:00
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2005-04-16 15:20:36 -07:00
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2009-05-07 22:24:37 +09:00
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2005-04-16 15:20:36 -07:00
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2008-09-14 05:55:09 -07:00
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2005-04-16 15:20:36 -07:00
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2005-11-11 05:31:37 -06:00
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2005-04-16 15:20:36 -07:00
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2006-09-30 20:29:12 +02:00
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2005-04-16 15:20:36 -07:00
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2007-07-16 08:52:14 +02:00
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2005-04-16 15:20:36 -07:00
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2008-08-14 09:59:13 +02:00
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2005-04-16 15:20:36 -07:00
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2006-08-10 08:44:47 +02:00
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2005-04-16 15:20:36 -07:00
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blk-mq: new multi-queue block IO queueing mechanism
Linux currently has two models for block devices:
- The classic request_fn based approach, where drivers use struct
request units for IO. The block layer provides various helper
functionalities to let drivers share code, things like tag
management, timeout handling, queueing, etc.
- The "stacked" approach, where a driver squeezes in between the
block layer and IO submitter. Since this bypasses the IO stack,
driver generally have to manage everything themselves.
With drivers being written for new high IOPS devices, the classic
request_fn based driver doesn't work well enough. The design dates
back to when both SMP and high IOPS was rare. It has problems with
scaling to bigger machines, and runs into scaling issues even on
smaller machines when you have IOPS in the hundreds of thousands
per device.
The stacked approach is then most often selected as the model
for the driver. But this means that everybody has to re-invent
everything, and along with that we get all the problems again
that the shared approach solved.
This commit introduces blk-mq, block multi queue support. The
design is centered around per-cpu queues for queueing IO, which
then funnel down into x number of hardware submission queues.
We might have a 1:1 mapping between the two, or it might be
an N:M mapping. That all depends on what the hardware supports.
blk-mq provides various helper functions, which include:
- Scalable support for request tagging. Most devices need to
be able to uniquely identify a request both in the driver and
to the hardware. The tagging uses per-cpu caches for freed
tags, to enable cache hot reuse.
- Timeout handling without tracking request on a per-device
basis. Basically the driver should be able to get a notification,
if a request happens to fail.
- Optional support for non 1:1 mappings between issue and
submission queues. blk-mq can redirect IO completions to the
desired location.
- Support for per-request payloads. Drivers almost always need
to associate a request structure with some driver private
command structure. Drivers can tell blk-mq this at init time,
and then any request handed to the driver will have the
required size of memory associated with it.
- Support for merging of IO, and plugging. The stacked model
gets neither of these. Even for high IOPS devices, merging
sequential IO reduces per-command overhead and thus
increases bandwidth.
For now, this is provided as a potential 3rd queueing model, with
the hope being that, as it matures, it can replace both the classic
and stacked model. That would get us back to having just 1 real
model for block devices, leaving the stacked approach to dm/md
devices (as it was originally intended).
Contributions in this patch from the following people:
Shaohua Li <shli@fusionio.com>
Alexander Gordeev <agordeev@redhat.com>
Christoph Hellwig <hch@infradead.org>
Mike Christie <michaelc@cs.wisc.edu>
Matias Bjorling <m@bjorling.me>
Jeff Moyer <jmoyer@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-24 09:20:05 +01:00
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2007-07-24 09:28:11 +02:00
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2011-09-12 12:12:01 +02:00
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2007-07-24 09:28:11 +02:00
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2010-07-01 19:49:17 +09:00
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2005-04-16 15:20:36 -07:00
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2008-07-03 09:53:43 +02:00
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2006-01-09 16:02:34 +01:00
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2008-02-19 11:36:53 +01:00
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2008-10-01 16:12:15 +02:00
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2011-07-31 22:05:09 +02:00
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2005-04-16 15:20:36 -07:00
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2008-09-14 05:55:09 -07:00
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2005-04-16 15:20:36 -07:00
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2005-08-05 13:28:11 -07:00
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2005-04-16 15:20:36 -07:00
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2008-08-16 14:10:05 +09:00
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2009-05-22 17:17:51 -04:00
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2014-06-05 13:38:39 -06:00
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2009-05-22 17:17:51 -04:00
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2009-05-22 17:17:53 -04:00
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2009-09-30 13:54:20 +02:00
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2012-09-18 12:19:27 -04:00
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2009-11-10 11:50:21 +01:00
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2009-05-22 17:17:51 -04:00
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2010-02-26 00:20:39 -05:00
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2010-09-10 20:50:10 +02:00
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2009-05-22 17:17:51 -04:00
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2009-05-22 17:17:53 -04:00
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2009-11-10 11:50:21 +01:00
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2010-12-01 19:41:49 +01:00
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2011-05-18 10:37:35 +02:00
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2013-07-11 22:39:53 -07:00
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2009-05-22 17:17:51 -04:00
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2011-07-13 21:17:23 +02:00
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2005-04-16 15:20:36 -07:00
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2008-10-31 10:05:07 +01:00
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2012-06-04 20:40:58 -07:00
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2005-04-16 15:20:36 -07:00
|
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|
blkcg: implement per-blkg request allocation
Currently, request_queue has one request_list to allocate requests
from regardless of blkcg of the IO being issued. When the unified
request pool is used up, cfq proportional IO limits become meaningless
- whoever grabs the next request being freed wins the race regardless
of the configured weights.
This can be easily demonstrated by creating a blkio cgroup w/ very low
weight, put a program which can issue a lot of random direct IOs there
and running a sequential IO from a different cgroup. As soon as the
request pool is used up, the sequential IO bandwidth crashes.
This patch implements per-blkg request_list. Each blkg has its own
request_list and any IO allocates its request from the matching blkg
making blkcgs completely isolated in terms of request allocation.
* Root blkcg uses the request_list embedded in each request_queue,
which was renamed to @q->root_rl from @q->rq. While making blkcg rl
handling a bit harier, this enables avoiding most overhead for root
blkcg.
* Queue fullness is properly per request_list but bdi isn't blkcg
aware yet, so congestion state currently just follows the root
blkcg. As writeback isn't aware of blkcg yet, this works okay for
async congestion but readahead may get the wrong signals. It's
better than blkcg completely collapsing with shared request_list but
needs to be improved with future changes.
* After this change, each block cgroup gets a full request pool making
resource consumption of each cgroup higher. This makes allowing
non-root users to create cgroups less desirable; however, note that
allowing non-root users to directly manage cgroups is already
severely broken regardless of this patch - each block cgroup
consumes kernel memory and skews IO weight (IO weights are not
hierarchical).
v2: queue-sysfs.txt updated and patch description udpated as suggested
by Vivek.
v3: blk_get_rl() wasn't checking error return from
blkg_lookup_create() and may cause oops on lookup failure. Fix it
by falling back to root_rl on blkg lookup failures. This problem
was spotted by Rakesh Iyer <rni@google.com>.
v4: Updated to accomodate 458f27a982 "block: Avoid missed wakeup in
request waitqueue". blk_drain_queue() now wakes up waiters on all
blkg->rl on the target queue.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-06-26 15:05:44 -07:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2005-04-16 15:20:36 -07:00
|
|
|
|
blkcg: implement per-blkg request allocation
Currently, request_queue has one request_list to allocate requests
from regardless of blkcg of the IO being issued. When the unified
request pool is used up, cfq proportional IO limits become meaningless
- whoever grabs the next request being freed wins the race regardless
of the configured weights.
This can be easily demonstrated by creating a blkio cgroup w/ very low
weight, put a program which can issue a lot of random direct IOs there
and running a sequential IO from a different cgroup. As soon as the
request pool is used up, the sequential IO bandwidth crashes.
This patch implements per-blkg request_list. Each blkg has its own
request_list and any IO allocates its request from the matching blkg
making blkcgs completely isolated in terms of request allocation.
* Root blkcg uses the request_list embedded in each request_queue,
which was renamed to @q->root_rl from @q->rq. While making blkcg rl
handling a bit harier, this enables avoiding most overhead for root
blkcg.
* Queue fullness is properly per request_list but bdi isn't blkcg
aware yet, so congestion state currently just follows the root
blkcg. As writeback isn't aware of blkcg yet, this works okay for
async congestion but readahead may get the wrong signals. It's
better than blkcg completely collapsing with shared request_list but
needs to be improved with future changes.
* After this change, each block cgroup gets a full request pool making
resource consumption of each cgroup higher. This makes allowing
non-root users to create cgroups less desirable; however, note that
allowing non-root users to directly manage cgroups is already
severely broken regardless of this patch - each block cgroup
consumes kernel memory and skews IO weight (IO weights are not
hierarchical).
v2: queue-sysfs.txt updated and patch description udpated as suggested
by Vivek.
v3: blk_get_rl() wasn't checking error return from
blkg_lookup_create() and may cause oops on lookup failure. Fix it
by falling back to root_rl on blkg lookup failures. This problem
was spotted by Rakesh Iyer <rni@google.com>.
v4: Updated to accomodate 458f27a982 "block: Avoid missed wakeup in
request waitqueue". blk_drain_queue() now wakes up waiters on all
blkg->rl on the target queue.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-06-26 15:05:44 -07:00
|
|
|
|
2005-04-16 15:20:36 -07:00
|
|
|
|
|
|
|
|
|
|
|
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|
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|
|
|
2010-07-01 19:49:17 +09:00
|
|
|
|
2005-04-16 15:20:36 -07:00
|
|
|
|
2006-01-09 16:02:34 +01:00
|
|
|
|
2008-09-14 05:55:09 -07:00
|
|
|
|
2008-02-19 11:36:53 +01:00
|
|
|
|
2008-10-01 16:12:15 +02:00
|
|
|
|
2005-04-16 15:20:36 -07:00
|
|
|
|
blk-mq: new multi-queue block IO queueing mechanism
Linux currently has two models for block devices:
- The classic request_fn based approach, where drivers use struct
request units for IO. The block layer provides various helper
functionalities to let drivers share code, things like tag
management, timeout handling, queueing, etc.
- The "stacked" approach, where a driver squeezes in between the
block layer and IO submitter. Since this bypasses the IO stack,
driver generally have to manage everything themselves.
With drivers being written for new high IOPS devices, the classic
request_fn based driver doesn't work well enough. The design dates
back to when both SMP and high IOPS was rare. It has problems with
scaling to bigger machines, and runs into scaling issues even on
smaller machines when you have IOPS in the hundreds of thousands
per device.
The stacked approach is then most often selected as the model
for the driver. But this means that everybody has to re-invent
everything, and along with that we get all the problems again
that the shared approach solved.
This commit introduces blk-mq, block multi queue support. The
design is centered around per-cpu queues for queueing IO, which
then funnel down into x number of hardware submission queues.
We might have a 1:1 mapping between the two, or it might be
an N:M mapping. That all depends on what the hardware supports.
blk-mq provides various helper functions, which include:
- Scalable support for request tagging. Most devices need to
be able to uniquely identify a request both in the driver and
to the hardware. The tagging uses per-cpu caches for freed
tags, to enable cache hot reuse.
- Timeout handling without tracking request on a per-device
basis. Basically the driver should be able to get a notification,
if a request happens to fail.
- Optional support for non 1:1 mappings between issue and
submission queues. blk-mq can redirect IO completions to the
desired location.
- Support for per-request payloads. Drivers almost always need
to associate a request structure with some driver private
command structure. Drivers can tell blk-mq this at init time,
and then any request handed to the driver will have the
required size of memory associated with it.
- Support for merging of IO, and plugging. The stacked model
gets neither of these. Even for high IOPS devices, merging
sequential IO reduces per-command overhead and thus
increases bandwidth.
For now, this is provided as a potential 3rd queueing model, with
the hope being that, as it matures, it can replace both the classic
and stacked model. That would get us back to having just 1 real
model for block devices, leaving the stacked approach to dm/md
devices (as it was originally intended).
Contributions in this patch from the following people:
Shaohua Li <shli@fusionio.com>
Alexander Gordeev <agordeev@redhat.com>
Christoph Hellwig <hch@infradead.org>
Mike Christie <michaelc@cs.wisc.edu>
Matias Bjorling <m@bjorling.me>
Jeff Moyer <jmoyer@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-24 09:20:05 +01:00
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
2014-06-03 11:24:06 +08:00
|
|
|
|
blk-mq: new multi-queue block IO queueing mechanism
Linux currently has two models for block devices:
- The classic request_fn based approach, where drivers use struct
request units for IO. The block layer provides various helper
functionalities to let drivers share code, things like tag
management, timeout handling, queueing, etc.
- The "stacked" approach, where a driver squeezes in between the
block layer and IO submitter. Since this bypasses the IO stack,
driver generally have to manage everything themselves.
With drivers being written for new high IOPS devices, the classic
request_fn based driver doesn't work well enough. The design dates
back to when both SMP and high IOPS was rare. It has problems with
scaling to bigger machines, and runs into scaling issues even on
smaller machines when you have IOPS in the hundreds of thousands
per device.
The stacked approach is then most often selected as the model
for the driver. But this means that everybody has to re-invent
everything, and along with that we get all the problems again
that the shared approach solved.
This commit introduces blk-mq, block multi queue support. The
design is centered around per-cpu queues for queueing IO, which
then funnel down into x number of hardware submission queues.
We might have a 1:1 mapping between the two, or it might be
an N:M mapping. That all depends on what the hardware supports.
blk-mq provides various helper functions, which include:
- Scalable support for request tagging. Most devices need to
be able to uniquely identify a request both in the driver and
to the hardware. The tagging uses per-cpu caches for freed
tags, to enable cache hot reuse.
- Timeout handling without tracking request on a per-device
basis. Basically the driver should be able to get a notification,
if a request happens to fail.
- Optional support for non 1:1 mappings between issue and
submission queues. blk-mq can redirect IO completions to the
desired location.
- Support for per-request payloads. Drivers almost always need
to associate a request structure with some driver private
command structure. Drivers can tell blk-mq this at init time,
and then any request handed to the driver will have the
required size of memory associated with it.
- Support for merging of IO, and plugging. The stacked model
gets neither of these. Even for high IOPS devices, merging
sequential IO reduces per-command overhead and thus
increases bandwidth.
For now, this is provided as a potential 3rd queueing model, with
the hope being that, as it matures, it can replace both the classic
and stacked model. That would get us back to having just 1 real
model for block devices, leaving the stacked approach to dm/md
devices (as it was originally intended).
Contributions in this patch from the following people:
Shaohua Li <shli@fusionio.com>
Alexander Gordeev <agordeev@redhat.com>
Christoph Hellwig <hch@infradead.org>
Mike Christie <michaelc@cs.wisc.edu>
Matias Bjorling <m@bjorling.me>
Jeff Moyer <jmoyer@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-24 09:20:05 +01:00
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2005-10-20 16:23:44 +02:00
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2005-10-20 16:37:00 +02:00
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2005-10-20 16:23:44 +02:00
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2005-04-16 15:20:36 -07:00
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2011-03-02 11:08:00 -05:00
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2005-04-16 15:20:36 -07:00
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2011-03-02 11:08:00 -05:00
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2005-04-16 15:20:36 -07:00
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2011-07-13 21:17:23 +02:00
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2005-04-16 15:20:36 -07:00
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2011-07-13 21:17:23 +02:00
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2005-04-16 15:20:36 -07:00
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2011-12-14 00:33:37 +01:00
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2005-04-16 15:20:36 -07:00
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2011-07-13 21:17:23 +02:00
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2005-04-16 15:20:36 -07:00
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2011-07-13 21:17:23 +02:00
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2005-04-16 15:20:36 -07:00
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2005-04-12 16:22:06 -05:00
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2005-04-16 15:20:36 -07:00
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2005-04-12 16:22:06 -05:00
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2005-04-16 15:20:36 -07:00
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blk-mq: new multi-queue block IO queueing mechanism
Linux currently has two models for block devices:
- The classic request_fn based approach, where drivers use struct
request units for IO. The block layer provides various helper
functionalities to let drivers share code, things like tag
management, timeout handling, queueing, etc.
- The "stacked" approach, where a driver squeezes in between the
block layer and IO submitter. Since this bypasses the IO stack,
driver generally have to manage everything themselves.
With drivers being written for new high IOPS devices, the classic
request_fn based driver doesn't work well enough. The design dates
back to when both SMP and high IOPS was rare. It has problems with
scaling to bigger machines, and runs into scaling issues even on
smaller machines when you have IOPS in the hundreds of thousands
per device.
The stacked approach is then most often selected as the model
for the driver. But this means that everybody has to re-invent
everything, and along with that we get all the problems again
that the shared approach solved.
This commit introduces blk-mq, block multi queue support. The
design is centered around per-cpu queues for queueing IO, which
then funnel down into x number of hardware submission queues.
We might have a 1:1 mapping between the two, or it might be
an N:M mapping. That all depends on what the hardware supports.
blk-mq provides various helper functions, which include:
- Scalable support for request tagging. Most devices need to
be able to uniquely identify a request both in the driver and
to the hardware. The tagging uses per-cpu caches for freed
tags, to enable cache hot reuse.
- Timeout handling without tracking request on a per-device
basis. Basically the driver should be able to get a notification,
if a request happens to fail.
- Optional support for non 1:1 mappings between issue and
submission queues. blk-mq can redirect IO completions to the
desired location.
- Support for per-request payloads. Drivers almost always need
to associate a request structure with some driver private
command structure. Drivers can tell blk-mq this at init time,
and then any request handed to the driver will have the
required size of memory associated with it.
- Support for merging of IO, and plugging. The stacked model
gets neither of these. Even for high IOPS devices, merging
sequential IO reduces per-command overhead and thus
increases bandwidth.
For now, this is provided as a potential 3rd queueing model, with
the hope being that, as it matures, it can replace both the classic
and stacked model. That would get us back to having just 1 real
model for block devices, leaving the stacked approach to dm/md
devices (as it was originally intended).
Contributions in this patch from the following people:
Shaohua Li <shli@fusionio.com>
Alexander Gordeev <agordeev@redhat.com>
Christoph Hellwig <hch@infradead.org>
Mike Christie <michaelc@cs.wisc.edu>
Matias Bjorling <m@bjorling.me>
Jeff Moyer <jmoyer@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-24 09:20:05 +01:00
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2013-03-23 11:42:26 +08:00
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2005-04-16 15:20:36 -07:00
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2008-01-10 11:30:36 -06:00
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2011-07-13 21:17:23 +02:00
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2008-03-04 11:18:17 +01:00
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2005-04-16 15:20:36 -07:00
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2007-10-25 10:14:47 +02:00
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2005-04-16 15:20:36 -07:00
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2005-11-10 08:52:05 +01:00
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2009-05-20 08:54:31 +02:00
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2012-11-28 13:46:45 +01:00
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2005-04-16 15:20:36 -07:00
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2008-09-14 05:55:09 -07:00
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2011-12-14 00:33:41 +01:00
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2012-03-05 13:15:18 -08:00
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2012-04-13 13:11:33 -07:00
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2012-04-16 13:57:25 -07:00
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2012-03-05 13:15:19 -08:00
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2012-03-05 13:15:18 -08:00
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2011-12-14 00:33:41 +01:00
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2009-05-22 17:17:51 -04:00
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2005-04-16 15:20:36 -07:00
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2005-06-23 00:08:19 -07:00
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2006-09-29 01:59:40 -07:00
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2006-03-23 20:00:26 +01:00
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2006-09-29 01:59:40 -07:00
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2005-04-16 15:20:36 -07:00
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2010-09-03 11:56:16 +02:00
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2005-04-16 15:20:36 -07:00
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2010-09-03 11:56:16 +02:00
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2011-05-06 11:34:32 -06:00
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block: hold queue if flush is running for non-queueable flush drive
In some drives, flush requests are non-queueable. When flush request is
running, normal read/write requests can't run. If block layer dispatches
such request, driver can't handle it and requeue it. Tejun suggested we
can hold the queue when flush is running. This can avoid unnecessary
requeue. Also this can improve performance. For example, we have
request flush1, write1, flush 2. flush1 is dispatched, then queue is
hold, write1 isn't inserted to queue. After flush1 is finished, flush2
will be dispatched. Since disk cache is already clean, flush2 will be
finished very soon, so looks like flush2 is folded to flush1.
In my test, the queue holding completely solves a regression introduced by
commit 53d63e6b0dfb95882ec0219ba6bbd50cde423794:
block: make the flush insertion use the tail of the dispatch list
It's not a preempt type request, in fact we have to insert it
behind requests that do specify INSERT_FRONT.
which causes about 20% regression running a sysbench fileio
workload.
Stable: 2.6.39 only
Cc: stable@kernel.org
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-05-06 11:34:41 -06:00
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2011-01-25 12:43:54 +01:00
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2014-02-10 09:29:00 -07:00
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2006-03-18 18:34:37 -05:00
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2014-05-28 08:08:02 -06:00
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2006-03-18 18:34:37 -05:00
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2007-07-09 12:40:35 +02:00
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2012-03-05 13:14:58 -08:00
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2007-07-09 12:40:35 +02:00
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2011-07-31 22:05:09 +02:00
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2007-07-09 12:40:35 +02:00
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2010-09-15 17:06:35 -04:00
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2013-01-09 08:05:13 -08:00
|
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|
blk-mq: new multi-queue block IO queueing mechanism
Linux currently has two models for block devices:
- The classic request_fn based approach, where drivers use struct
request units for IO. The block layer provides various helper
functionalities to let drivers share code, things like tag
management, timeout handling, queueing, etc.
- The "stacked" approach, where a driver squeezes in between the
block layer and IO submitter. Since this bypasses the IO stack,
driver generally have to manage everything themselves.
With drivers being written for new high IOPS devices, the classic
request_fn based driver doesn't work well enough. The design dates
back to when both SMP and high IOPS was rare. It has problems with
scaling to bigger machines, and runs into scaling issues even on
smaller machines when you have IOPS in the hundreds of thousands
per device.
The stacked approach is then most often selected as the model
for the driver. But this means that everybody has to re-invent
everything, and along with that we get all the problems again
that the shared approach solved.
This commit introduces blk-mq, block multi queue support. The
design is centered around per-cpu queues for queueing IO, which
then funnel down into x number of hardware submission queues.
We might have a 1:1 mapping between the two, or it might be
an N:M mapping. That all depends on what the hardware supports.
blk-mq provides various helper functions, which include:
- Scalable support for request tagging. Most devices need to
be able to uniquely identify a request both in the driver and
to the hardware. The tagging uses per-cpu caches for freed
tags, to enable cache hot reuse.
- Timeout handling without tracking request on a per-device
basis. Basically the driver should be able to get a notification,
if a request happens to fail.
- Optional support for non 1:1 mappings between issue and
submission queues. blk-mq can redirect IO completions to the
desired location.
- Support for per-request payloads. Drivers almost always need
to associate a request structure with some driver private
command structure. Drivers can tell blk-mq this at init time,
and then any request handed to the driver will have the
required size of memory associated with it.
- Support for merging of IO, and plugging. The stacked model
gets neither of these. Even for high IOPS devices, merging
sequential IO reduces per-command overhead and thus
increases bandwidth.
For now, this is provided as a potential 3rd queueing model, with
the hope being that, as it matures, it can replace both the classic
and stacked model. That would get us back to having just 1 real
model for block devices, leaving the stacked approach to dm/md
devices (as it was originally intended).
Contributions in this patch from the following people:
Shaohua Li <shli@fusionio.com>
Alexander Gordeev <agordeev@redhat.com>
Christoph Hellwig <hch@infradead.org>
Mike Christie <michaelc@cs.wisc.edu>
Matias Bjorling <m@bjorling.me>
Jeff Moyer <jmoyer@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-24 09:20:05 +01:00
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2014-05-13 15:10:52 -06:00
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2005-04-16 15:20:36 -07:00
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2009-04-06 14:48:01 +02:00
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2012-11-28 13:42:38 +01:00
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2012-03-05 13:14:58 -08:00
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2011-04-19 13:32:46 +02:00
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2011-07-23 20:44:25 +02:00
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2011-04-19 13:32:46 +02:00
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2008-10-27 18:44:46 +09:00
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2011-04-19 13:32:46 +02:00
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2011-07-23 20:44:25 +02:00
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2012-12-06 14:32:01 +01:00
|
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|
|
blk-mq: new multi-queue block IO queueing mechanism
Linux currently has two models for block devices:
- The classic request_fn based approach, where drivers use struct
request units for IO. The block layer provides various helper
functionalities to let drivers share code, things like tag
management, timeout handling, queueing, etc.
- The "stacked" approach, where a driver squeezes in between the
block layer and IO submitter. Since this bypasses the IO stack,
driver generally have to manage everything themselves.
With drivers being written for new high IOPS devices, the classic
request_fn based driver doesn't work well enough. The design dates
back to when both SMP and high IOPS was rare. It has problems with
scaling to bigger machines, and runs into scaling issues even on
smaller machines when you have IOPS in the hundreds of thousands
per device.
The stacked approach is then most often selected as the model
for the driver. But this means that everybody has to re-invent
everything, and along with that we get all the problems again
that the shared approach solved.
This commit introduces blk-mq, block multi queue support. The
design is centered around per-cpu queues for queueing IO, which
then funnel down into x number of hardware submission queues.
We might have a 1:1 mapping between the two, or it might be
an N:M mapping. That all depends on what the hardware supports.
blk-mq provides various helper functions, which include:
- Scalable support for request tagging. Most devices need to
be able to uniquely identify a request both in the driver and
to the hardware. The tagging uses per-cpu caches for freed
tags, to enable cache hot reuse.
- Timeout handling without tracking request on a per-device
basis. Basically the driver should be able to get a notification,
if a request happens to fail.
- Optional support for non 1:1 mappings between issue and
submission queues. blk-mq can redirect IO completions to the
desired location.
- Support for per-request payloads. Drivers almost always need
to associate a request structure with some driver private
command structure. Drivers can tell blk-mq this at init time,
and then any request handed to the driver will have the
required size of memory associated with it.
- Support for merging of IO, and plugging. The stacked model
gets neither of these. Even for high IOPS devices, merging
sequential IO reduces per-command overhead and thus
increases bandwidth.
For now, this is provided as a potential 3rd queueing model, with
the hope being that, as it matures, it can replace both the classic
and stacked model. That would get us back to having just 1 real
model for block devices, leaving the stacked approach to dm/md
devices (as it was originally intended).
Contributions in this patch from the following people:
Shaohua Li <shli@fusionio.com>
Alexander Gordeev <agordeev@redhat.com>
Christoph Hellwig <hch@infradead.org>
Mike Christie <michaelc@cs.wisc.edu>
Matias Bjorling <m@bjorling.me>
Jeff Moyer <jmoyer@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-24 09:20:05 +01:00
|
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|
2014-05-29 09:53:32 -06:00
|
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2014-06-24 16:22:24 -06:00
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2009-01-23 10:54:44 +01:00
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2009-09-03 20:06:47 +02:00
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2010-06-09 10:42:09 +02:00
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2006-01-06 09:51:03 +01:00
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2013-11-19 09:25:07 -07:00
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2012-03-30 12:33:28 +02:00
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2008-04-29 10:16:38 -07:00
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2012-03-30 12:33:28 +02:00
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2008-04-29 10:16:38 -07:00
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2008-04-29 14:48:33 +02:00
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2008-07-03 13:18:54 +02:00
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2012-03-30 12:33:28 +02:00
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2008-07-03 13:18:54 +02:00
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2012-03-30 12:33:28 +02:00
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2008-07-03 13:18:54 +02:00
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2008-04-29 14:48:33 +02:00
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2012-03-30 12:33:28 +02:00
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2008-04-29 14:48:33 +02:00
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2009-05-20 08:54:31 +02:00
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2008-04-29 14:48:33 +02:00
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2012-03-30 12:33:28 +02:00
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2008-04-29 14:48:33 +02:00
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2005-04-16 15:20:36 -07:00
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2012-11-28 13:42:38 +01:00
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2012-12-06 14:32:01 +01:00
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2012-03-05 13:14:58 -08:00
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blk-mq: new multi-queue block IO queueing mechanism
Linux currently has two models for block devices:
- The classic request_fn based approach, where drivers use struct
request units for IO. The block layer provides various helper
functionalities to let drivers share code, things like tag
management, timeout handling, queueing, etc.
- The "stacked" approach, where a driver squeezes in between the
block layer and IO submitter. Since this bypasses the IO stack,
driver generally have to manage everything themselves.
With drivers being written for new high IOPS devices, the classic
request_fn based driver doesn't work well enough. The design dates
back to when both SMP and high IOPS was rare. It has problems with
scaling to bigger machines, and runs into scaling issues even on
smaller machines when you have IOPS in the hundreds of thousands
per device.
The stacked approach is then most often selected as the model
for the driver. But this means that everybody has to re-invent
everything, and along with that we get all the problems again
that the shared approach solved.
This commit introduces blk-mq, block multi queue support. The
design is centered around per-cpu queues for queueing IO, which
then funnel down into x number of hardware submission queues.
We might have a 1:1 mapping between the two, or it might be
an N:M mapping. That all depends on what the hardware supports.
blk-mq provides various helper functions, which include:
- Scalable support for request tagging. Most devices need to
be able to uniquely identify a request both in the driver and
to the hardware. The tagging uses per-cpu caches for freed
tags, to enable cache hot reuse.
- Timeout handling without tracking request on a per-device
basis. Basically the driver should be able to get a notification,
if a request happens to fail.
- Optional support for non 1:1 mappings between issue and
submission queues. blk-mq can redirect IO completions to the
desired location.
- Support for per-request payloads. Drivers almost always need
to associate a request structure with some driver private
command structure. Drivers can tell blk-mq this at init time,
and then any request handed to the driver will have the
required size of memory associated with it.
- Support for merging of IO, and plugging. The stacked model
gets neither of these. Even for high IOPS devices, merging
sequential IO reduces per-command overhead and thus
increases bandwidth.
For now, this is provided as a potential 3rd queueing model, with
the hope being that, as it matures, it can replace both the classic
and stacked model. That would get us back to having just 1 real
model for block devices, leaving the stacked approach to dm/md
devices (as it was originally intended).
Contributions in this patch from the following people:
Shaohua Li <shli@fusionio.com>
Alexander Gordeev <agordeev@redhat.com>
Christoph Hellwig <hch@infradead.org>
Mike Christie <michaelc@cs.wisc.edu>
Matias Bjorling <m@bjorling.me>
Jeff Moyer <jmoyer@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-24 09:20:05 +01:00
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2008-04-29 14:44:19 +02:00
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2010-01-29 09:04:08 +01:00
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2008-09-24 13:03:33 +02:00
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2009-01-23 10:54:44 +01:00
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2010-06-09 10:42:09 +02:00
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block: add a queue flag for request stacking support
This patch adds a queue flag to indicate the block device can be
used for request stacking.
Request stacking drivers need to stack their devices on top of
only devices of which q->request_fn is functional.
Since bio stacking drivers (e.g. md, loop) basically initialize
their queue using blk_alloc_queue() and don't set q->request_fn,
the check of (q->request_fn == NULL) looks enough for that purpose.
However, dm will become both types of stacking driver (bio-based and
request-based). And dm will always set q->request_fn even if the dm
device is bio-based of which q->request_fn is not functional actually.
So we need something else to distinguish the type of the device.
Adding a queue flag is a solution for that.
The reason why dm always sets q->request_fn is to keep
the compatibility of dm user-space tools.
Currently, all dm user-space tools are using bio-based dm without
specifying the type of the dm device they use.
To use request-based dm without changing such tools, the kernel
must decide the type of the dm device automatically.
The automatic type decision can't be done at the device creation time
and needs to be deferred until such tools load a mapping table,
since the actual type is decided by dm target type included in
the mapping table.
So a dm device has to be initialized using blk_init_queue()
so that we can load either type of table.
Then, all queue stuffs are set (e.g. q->request_fn) and we have
no element to distinguish that it is bio-based or request-based,
even after a table is loaded and the type of the device is decided.
By the way, some stuffs of the queue (e.g. request_list, elevator)
are needless when the dm device is used as bio-based.
But the memory size is not so large (about 20[KB] per queue on ia64),
so I hope the memory loss can be acceptable for bio-based dm users.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-09-18 10:46:13 -04:00
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2009-09-30 13:52:12 +02:00
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2010-08-11 14:17:49 -07:00
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2005-04-16 15:20:36 -07:00
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2010-08-07 18:17:56 +02:00
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2012-09-18 12:19:25 -04:00
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2010-08-07 18:17:56 +02:00
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2005-04-16 15:20:36 -07:00
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2010-08-07 18:17:56 +02:00
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2005-04-16 15:20:36 -07:00
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2008-08-26 10:25:02 +02:00
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2007-07-16 08:52:14 +02:00
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2007-12-11 17:40:30 -05:00
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2005-04-16 15:20:36 -07:00
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2013-05-23 12:25:08 +02:00
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2005-04-16 15:20:36 -07:00
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2014-04-16 10:57:18 -06:00
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2010-12-01 19:41:49 +01:00
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2006-07-28 09:26:13 +02:00
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2009-04-06 14:48:01 +02:00
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2006-07-28 09:26:13 +02:00
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2009-04-06 14:48:01 +02:00
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2010-08-07 18:20:39 +02:00
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2009-04-06 14:48:01 +02:00
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2012-06-04 20:40:59 -07:00
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2005-04-16 15:20:36 -07:00
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2012-06-04 20:40:59 -07:00
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2005-04-16 15:20:36 -07:00
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2012-06-04 20:40:59 -07:00
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2005-04-16 15:20:36 -07:00
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2012-06-04 20:40:59 -07:00
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2005-04-16 15:20:36 -07:00
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2012-06-04 20:40:59 -07:00
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2005-04-16 15:20:36 -07:00
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2012-06-04 20:40:59 -07:00
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2005-04-16 15:20:36 -07:00
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2012-09-18 12:19:25 -04:00
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2005-04-16 15:20:36 -07:00
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2012-09-18 12:19:25 -04:00
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2005-04-16 15:20:36 -07:00
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2012-09-18 12:19:26 -04:00
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2012-09-18 12:19:27 -04:00
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2012-09-18 12:19:26 -04:00
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2012-09-18 12:19:27 -04:00
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2005-04-16 15:20:36 -07:00
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2008-04-21 09:51:05 +02:00
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2005-04-16 15:20:36 -07:00
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2008-04-21 09:51:05 +02:00
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2010-05-31 15:59:03 +09:00
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2005-04-16 15:20:36 -07:00
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2007-07-09 12:38:05 +02:00
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2008-12-05 14:49:18 -08:00
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2007-07-09 12:38:05 +02:00
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2007-07-17 04:03:37 -07:00
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2005-04-16 15:20:36 -07:00
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2007-07-24 09:28:11 +02:00
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2005-04-16 15:20:36 -07:00
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2007-07-24 09:28:11 +02:00
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2005-04-16 15:20:36 -07:00
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2008-08-28 16:17:06 +09:00
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2008-12-18 14:49:37 +09:00
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2008-12-18 14:49:38 +09:00
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2009-07-09 14:46:53 +02:00
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2008-08-28 16:17:06 +09:00
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2007-09-25 12:35:59 +02:00
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2013-11-23 17:19:00 -08:00
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2007-09-25 12:35:59 +02:00
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2009-02-23 09:03:10 +01:00
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2007-09-25 12:35:59 +02:00
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2005-04-16 15:20:36 -07:00
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2007-09-25 12:35:59 +02:00
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2013-11-23 17:19:00 -08:00
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2007-09-25 12:35:59 +02:00
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2013-08-07 14:26:21 -07:00
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2013-11-23 17:19:00 -08:00
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2013-08-07 14:26:21 -07:00
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2007-09-25 12:35:59 +02:00
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2009-11-26 09:16:19 +01:00
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2005-04-16 15:20:36 -07:00
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2008-04-29 09:54:36 +02:00
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2005-04-16 15:20:36 -07:00
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2007-07-24 09:28:11 +02:00
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2009-05-17 18:57:15 +03:00
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2014-06-06 07:57:37 -06:00
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2007-07-24 09:28:11 +02:00
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2010-06-18 16:59:42 +02:00
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2008-09-18 10:45:38 -04:00
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2008-10-01 16:12:15 +02:00
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block: add request clone interface (v2)
This patch adds the following 2 interfaces for request-stacking drivers:
- blk_rq_prep_clone(struct request *clone, struct request *orig,
struct bio_set *bs, gfp_t gfp_mask,
int (*bio_ctr)(struct bio *, struct bio*, void *),
void *data)
* Clones bios in the original request to the clone request
(bio_ctr is called for each cloned bios.)
* Copies attributes of the original request to the clone request.
The actual data parts (e.g. ->cmd, ->buffer, ->sense) are not
copied.
- blk_rq_unprep_clone(struct request *clone)
* Frees cloned bios from the clone request.
Request stacking drivers (e.g. request-based dm) need to make a clone
request for a submitted request and dispatch it to other devices.
To allocate request for the clone, request stacking drivers may not
be able to use blk_get_request() because the allocation may be done
in an irq-disabled context.
So blk_rq_prep_clone() takes a request allocated by the caller
as an argument.
For each clone bio in the clone request, request stacking drivers
should be able to set up their own completion handler.
So blk_rq_prep_clone() takes a callback function which is called
for each clone bio, and a pointer for private data which is passed
to the callback.
NOTE:
blk_rq_prep_clone() doesn't copy any actual data of the original
request. Pages are shared between original bios and cloned bios.
So caller must not complete the original request before the clone
request.
Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-06-11 13:10:16 +02:00
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2008-09-18 10:45:38 -04:00
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2011-03-02 11:08:00 -05:00
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2007-07-24 09:28:11 +02:00
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2012-01-12 16:01:28 +01:00
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2012-01-12 16:01:27 +01:00
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2007-08-27 15:38:10 -04:00
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2008-09-02 17:16:41 -04:00
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2006-10-19 23:28:16 -07:00
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2011-09-12 12:12:01 +02:00
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2011-09-12 12:08:27 +02:00
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2006-10-19 23:28:16 -07:00
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2009-07-09 14:52:32 +02:00
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2006-10-19 23:28:16 -07:00
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2009-07-09 14:52:32 +02:00
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2006-10-19 23:28:16 -07:00
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2009-07-09 14:52:32 +02:00
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2006-10-19 23:28:16 -07:00
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2009-07-09 14:52:32 +02:00
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2006-10-19 23:28:16 -07:00
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2007-07-24 09:28:11 +02:00
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2005-04-16 15:20:36 -07:00
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2007-07-24 09:28:11 +02:00
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2011-04-18 11:41:33 +02:00
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2007-07-24 09:28:11 +02:00
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2011-04-19 13:32:46 +02:00
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2008-08-28 16:17:05 +09:00
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2008-08-28 16:17:06 +09:00
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2006-12-19 11:12:46 +01:00
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2007-07-24 09:28:11 +02:00
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2014-02-08 20:42:52 -05:00
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2007-07-24 09:28:11 +02:00
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2005-06-20 14:11:09 +02:00
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2007-07-24 09:28:11 +02:00
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2006-01-06 10:00:50 +01:00
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2005-11-11 05:30:24 -06:00
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2007-07-24 09:28:11 +02:00
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2005-04-16 15:20:36 -07:00
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2009-04-23 11:05:18 +09:00
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2009-07-03 17:48:17 +09:00
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2009-04-23 11:05:18 +09:00
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2009-05-07 22:24:38 +09:00
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2009-05-07 22:24:44 +09:00
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2009-05-07 22:24:41 +09:00
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2009-05-07 22:24:44 +09:00
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2009-05-07 22:24:38 +09:00
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2009-05-07 22:24:41 +09:00
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2009-04-23 11:05:18 +09:00
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2009-07-03 17:48:17 +09:00
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2009-05-07 22:24:38 +09:00
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2009-05-07 22:24:41 +09:00
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2009-05-07 22:24:38 +09:00
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2009-05-07 22:24:41 +09:00
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2009-05-07 22:24:38 +09:00
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2012-09-18 12:19:26 -04:00
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block: fix max discard sectors limit
linux-v3.8-rc1 and later support for plug for blkdev_issue_discard with
commit 0cfbcafcae8b7364b5fa96c2b26ccde7a3a296a9
(block: add plug for blkdev_issue_discard )
For example,
1) DISCARD rq-1 with size size 4GB
2) DISCARD rq-2 with size size 1GB
If these 2 discard requests get merged, final request size will be 5GB.
In this case, request's __data_len field may overflow as it can store
max 4GB(unsigned int).
This issue was observed while doing mkfs.f2fs on 5GB SD card:
https://lkml.org/lkml/2013/4/1/292
Info: sector size = 512
Info: total sectors = 11370496 (in 512bytes)
Info: zone aligned segment0 blkaddr: 512
[ 257.789764] blk_update_request: bio idx 0 >= vcnt 0
mkfs process gets stuck in D state and I see the following in the dmesg:
[ 257.789733] __end_that: dev mmcblk0: type=1, flags=122c8081
[ 257.789764] sector 4194304, nr/cnr 2981888/4294959104
[ 257.789764] bio df3840c0, biotail df3848c0, buffer (null), len
1526726656
[ 257.789764] blk_update_request: bio idx 0 >= vcnt 0
[ 257.794921] request botched: dev mmcblk0: type=1, flags=122c8081
[ 257.794921] sector 4194304, nr/cnr 2981888/4294959104
[ 257.794921] bio df3840c0, biotail df3848c0, buffer (null), len
1526726656
This patch fixes this issue.
Reported-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Tested-by: Max Filippov <jcmvbkbc@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-04-24 08:52:50 -06:00
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2012-09-18 12:19:26 -04:00
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2012-09-18 12:19:27 -04:00
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2012-09-18 12:19:26 -04:00
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2014-06-05 13:38:39 -06:00
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2014-06-17 22:09:29 -07:00
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2014-06-05 13:38:39 -06:00
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2012-09-18 12:19:26 -04:00
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2014-06-05 13:38:39 -06:00
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2012-09-18 12:19:26 -04:00
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2013-09-21 13:57:47 -06:00
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2009-05-08 11:54:16 +09:00
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2005-04-16 15:20:36 -07:00
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2009-04-23 11:05:18 +09:00
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2009-04-23 11:05:19 +09:00
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2005-04-16 15:20:36 -07:00
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2007-12-11 17:52:28 -05:00
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2005-04-16 15:20:36 -07:00
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2009-04-23 11:05:18 +09:00
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2014-04-16 09:44:59 +02:00
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2009-05-11 17:56:09 +09:00
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2009-07-03 17:48:17 +09:00
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2009-05-11 17:56:09 +09:00
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2009-07-03 17:48:17 +09:00
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2009-04-23 11:05:18 +09:00
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2006-01-09 16:02:34 +01:00
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2008-09-14 05:55:09 -07:00
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2010-07-01 19:49:17 +09:00
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2006-01-09 16:02:34 +01:00
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2005-04-16 15:20:36 -07:00
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2007-07-24 09:28:11 +02:00
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2005-06-23 00:08:19 -07:00
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2007-07-24 09:28:11 +02:00
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2010-05-11 08:57:42 +02:00
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2007-07-24 09:28:11 +02:00
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2010-12-17 08:34:20 +01:00
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2010-02-26 00:20:38 -05:00
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2014-06-05 13:38:39 -06:00
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2010-02-26 00:20:39 -05:00
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2007-07-24 09:28:11 +02:00
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2009-09-30 13:54:20 +02:00
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2012-09-18 12:19:27 -04:00
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2009-05-22 17:17:49 -04:00
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2010-10-13 21:18:03 +02:00
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2009-05-22 17:17:53 -04:00
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2009-07-31 11:49:11 -04:00
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2009-05-22 17:17:53 -04:00
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2009-09-11 21:54:52 +02:00
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2009-05-22 17:17:53 -04:00
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2009-06-16 08:23:52 +02:00
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2012-01-11 16:27:11 +01:00
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2009-05-22 17:17:53 -04:00
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2010-01-11 03:21:49 -05:00
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2009-05-22 17:17:53 -04:00
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2007-07-24 09:28:11 +02:00
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2008-03-04 11:18:17 +01:00
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2008-07-04 09:30:03 +02:00
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2008-02-19 11:36:53 +01:00
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2008-10-01 16:12:15 +02:00
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2007-07-24 09:28:11 +02:00
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2010-07-01 19:49:17 +09:00
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2007-07-24 09:28:11 +02:00
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2007-12-31 16:37:00 -06:00
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2007-07-24 09:28:11 +02:00
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2008-09-14 05:55:09 -07:00
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2010-09-03 11:56:16 +02:00
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2011-05-06 11:34:32 -06:00
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2005-04-16 15:20:36 -07:00
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2007-07-24 09:28:11 +02:00
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2012-08-02 23:42:04 +02:00
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2005-04-16 15:20:36 -07:00
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2011-12-14 00:33:38 +01:00
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2007-07-24 09:28:11 +02:00
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2005-04-16 15:20:36 -07:00
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2013-03-23 11:42:26 +08:00
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2011-07-08 08:19:21 +02:00
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2011-09-21 10:00:16 +02:00
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2011-07-08 08:19:21 +02:00
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2011-03-08 13:19:51 +01:00
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2011-09-21 10:00:16 +02:00
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|
blk-mq: new multi-queue block IO queueing mechanism
Linux currently has two models for block devices:
- The classic request_fn based approach, where drivers use struct
request units for IO. The block layer provides various helper
functionalities to let drivers share code, things like tag
management, timeout handling, queueing, etc.
- The "stacked" approach, where a driver squeezes in between the
block layer and IO submitter. Since this bypasses the IO stack,
driver generally have to manage everything themselves.
With drivers being written for new high IOPS devices, the classic
request_fn based driver doesn't work well enough. The design dates
back to when both SMP and high IOPS was rare. It has problems with
scaling to bigger machines, and runs into scaling issues even on
smaller machines when you have IOPS in the hundreds of thousands
per device.
The stacked approach is then most often selected as the model
for the driver. But this means that everybody has to re-invent
everything, and along with that we get all the problems again
that the shared approach solved.
This commit introduces blk-mq, block multi queue support. The
design is centered around per-cpu queues for queueing IO, which
then funnel down into x number of hardware submission queues.
We might have a 1:1 mapping between the two, or it might be
an N:M mapping. That all depends on what the hardware supports.
blk-mq provides various helper functions, which include:
- Scalable support for request tagging. Most devices need to
be able to uniquely identify a request both in the driver and
to the hardware. The tagging uses per-cpu caches for freed
tags, to enable cache hot reuse.
- Timeout handling without tracking request on a per-device
basis. Basically the driver should be able to get a notification,
if a request happens to fail.
- Optional support for non 1:1 mappings between issue and
submission queues. blk-mq can redirect IO completions to the
desired location.
- Support for per-request payloads. Drivers almost always need
to associate a request structure with some driver private
command structure. Drivers can tell blk-mq this at init time,
and then any request handed to the driver will have the
required size of memory associated with it.
- Support for merging of IO, and plugging. The stacked model
gets neither of these. Even for high IOPS devices, merging
sequential IO reduces per-command overhead and thus
increases bandwidth.
For now, this is provided as a potential 3rd queueing model, with
the hope being that, as it matures, it can replace both the classic
and stacked model. That would get us back to having just 1 real
model for block devices, leaving the stacked approach to dm/md
devices (as it was originally intended).
Contributions in this patch from the following people:
Shaohua Li <shli@fusionio.com>
Alexander Gordeev <agordeev@redhat.com>
Christoph Hellwig <hch@infradead.org>
Mike Christie <michaelc@cs.wisc.edu>
Matias Bjorling <m@bjorling.me>
Jeff Moyer <jmoyer@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-24 09:20:05 +01:00
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2011-09-21 10:00:16 +02:00
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2011-03-08 13:19:51 +01:00
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2011-07-08 08:19:20 +02:00
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2012-07-31 09:08:14 +02:00
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2012-07-31 09:08:15 +02:00
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2011-04-18 09:52:22 +02:00
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2012-07-31 09:08:14 +02:00
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2011-04-18 09:52:22 +02:00
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2012-07-31 09:08:14 +02:00
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2011-03-08 13:19:51 +01:00
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2011-04-15 15:49:07 +02:00
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2011-03-08 13:19:51 +01:00
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2011-04-16 13:27:55 +02:00
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2011-04-15 15:20:10 +02:00
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2011-04-15 15:49:07 +02:00
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2011-03-08 13:19:51 +01:00
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|
blk-mq: new multi-queue block IO queueing mechanism
Linux currently has two models for block devices:
- The classic request_fn based approach, where drivers use struct
request units for IO. The block layer provides various helper
functionalities to let drivers share code, things like tag
management, timeout handling, queueing, etc.
- The "stacked" approach, where a driver squeezes in between the
block layer and IO submitter. Since this bypasses the IO stack,
driver generally have to manage everything themselves.
With drivers being written for new high IOPS devices, the classic
request_fn based driver doesn't work well enough. The design dates
back to when both SMP and high IOPS was rare. It has problems with
scaling to bigger machines, and runs into scaling issues even on
smaller machines when you have IOPS in the hundreds of thousands
per device.
The stacked approach is then most often selected as the model
for the driver. But this means that everybody has to re-invent
everything, and along with that we get all the problems again
that the shared approach solved.
This commit introduces blk-mq, block multi queue support. The
design is centered around per-cpu queues for queueing IO, which
then funnel down into x number of hardware submission queues.
We might have a 1:1 mapping between the two, or it might be
an N:M mapping. That all depends on what the hardware supports.
blk-mq provides various helper functions, which include:
- Scalable support for request tagging. Most devices need to
be able to uniquely identify a request both in the driver and
to the hardware. The tagging uses per-cpu caches for freed
tags, to enable cache hot reuse.
- Timeout handling without tracking request on a per-device
basis. Basically the driver should be able to get a notification,
if a request happens to fail.
- Optional support for non 1:1 mappings between issue and
submission queues. blk-mq can redirect IO completions to the
desired location.
- Support for per-request payloads. Drivers almost always need
to associate a request structure with some driver private
command structure. Drivers can tell blk-mq this at init time,
and then any request handed to the driver will have the
required size of memory associated with it.
- Support for merging of IO, and plugging. The stacked model
gets neither of these. Even for high IOPS devices, merging
sequential IO reduces per-command overhead and thus
increases bandwidth.
For now, this is provided as a potential 3rd queueing model, with
the hope being that, as it matures, it can replace both the classic
and stacked model. That would get us back to having just 1 real
model for block devices, leaving the stacked approach to dm/md
devices (as it was originally intended).
Contributions in this patch from the following people:
Shaohua Li <shli@fusionio.com>
Alexander Gordeev <agordeev@redhat.com>
Christoph Hellwig <hch@infradead.org>
Mike Christie <michaelc@cs.wisc.edu>
Matias Bjorling <m@bjorling.me>
Jeff Moyer <jmoyer@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2013-10-24 09:20:05 +01:00
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2011-03-08 13:19:51 +01:00
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2005-04-16 15:20:36 -07:00
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2014-10-19 17:13:57 +02:00
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2007-07-24 09:28:11 +02:00
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2006-08-30 15:48:45 -04:00
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2005-04-16 15:20:36 -07:00
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2006-10-04 08:27:25 +02:00
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2010-09-16 20:51:46 +02:00
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2010-04-28 17:55:06 +04:00
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2012-09-18 12:19:27 -04:00
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2010-04-28 17:55:09 +04:00
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2010-09-16 20:51:46 +02:00
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2010-08-18 05:29:10 -04:00
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2008-08-05 18:01:53 +01:00
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2010-08-18 05:29:10 -04:00
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2008-08-05 18:01:53 +01:00
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2010-10-27 21:30:04 -04:00
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2010-10-27 23:44:47 -04:00
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2010-10-27 21:30:04 -04:00
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2010-10-27 23:44:47 -04:00
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2010-10-27 21:30:04 -04:00
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2005-04-16 15:20:36 -07:00
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2009-06-26 16:27:10 +02:00
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2008-06-26 13:48:27 +02:00
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2010-02-26 00:20:37 -05:00
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2008-12-03 12:55:08 +01:00
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2005-04-16 15:20:36 -07:00
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2009-05-22 17:17:50 -04:00
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2009-05-22 17:17:51 -04:00
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2009-05-22 17:17:50 -04:00
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2009-05-22 17:17:51 -04:00
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2009-05-22 17:17:50 -04:00
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2009-05-22 17:17:51 -04:00
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2009-05-22 17:17:50 -04:00
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2009-05-22 17:17:51 -04:00
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2009-05-22 17:17:50 -04:00
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2010-02-26 00:20:39 -05:00
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2009-05-22 17:17:50 -04:00
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2010-02-26 00:20:39 -05:00
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2009-05-22 17:17:50 -04:00
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2009-05-22 17:17:51 -04:00
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2009-05-22 17:17:50 -04:00
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2009-05-22 17:17:49 -04:00
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2005-04-16 15:20:36 -07:00
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2009-05-22 17:17:51 -04:00
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2005-04-16 15:20:36 -07:00
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2009-05-22 17:17:49 -04:00
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2005-04-16 15:20:36 -07:00
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2009-05-22 17:17:49 -04:00
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2005-04-16 15:20:36 -07:00
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2009-05-22 17:17:53 -04:00
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2010-10-13 21:18:03 +02:00
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2009-10-03 20:52:01 +02:00
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2009-05-22 17:17:53 -04:00
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2009-10-03 20:52:01 +02:00
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2009-05-22 17:17:53 -04:00
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2009-10-03 20:52:01 +02:00
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2009-05-22 17:17:53 -04:00
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2009-10-03 20:52:01 +02:00
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2009-05-22 17:17:53 -04:00
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2009-10-03 20:52:01 +02:00
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2009-05-22 17:17:53 -04:00
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2010-01-11 03:21:51 -05:00
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2009-12-29 08:35:35 +01:00
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2014-10-08 18:26:13 -04:00
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2009-12-29 08:35:35 +01:00
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2014-10-08 18:26:13 -04:00
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2009-05-22 17:17:53 -04:00
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2009-10-03 20:52:01 +02:00
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2009-11-10 11:50:21 +01:00
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2010-01-11 03:21:51 -05:00
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2009-11-10 11:50:21 +01:00
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2012-12-19 07:18:35 -08:00
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2010-01-11 03:21:48 -05:00
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2011-05-18 10:37:35 +02:00
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2012-12-19 07:18:35 -08:00
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2009-11-10 11:50:21 +01:00
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|
block: split discard into aligned requests
When a disk has large discard_granularity and small max_discard_sectors,
discards are not split with optimal alignment. In the limit case of
discard_granularity == max_discard_sectors, no request could be aligned
correctly, so in fact you might end up with no discarded logical blocks
at all.
Another example that helps showing the condition in the patch is with
discard_granularity == 64, max_discard_sectors == 128. A request that is
submitted for 256 sectors 2..257 will be split in two: 2..129, 130..257.
However, only 2 aligned blocks out of 3 are included in the request;
128..191 may be left intact and not discarded. With this patch, the
first request will be truncated to ensure good alignment of what's left,
and the split will be 2..127, 128..255, 256..257. The patch will also
take into account the discard_alignment.
At most one extra request will be introduced, because the first request
will be reduced by at most granularity-1 sectors, and granularity
must be less than max_discard_sectors. Subsequent requests will run
on round_down(max_discard_sectors, granularity) sectors, as in the
current code.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Tested-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-08-02 09:48:50 +02:00
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2009-12-03 09:24:48 +01:00
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2011-05-18 10:37:35 +02:00
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2009-12-03 09:24:48 +01:00
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2012-09-18 12:19:27 -04:00
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2007-07-24 09:28:11 +02:00
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2005-04-16 15:20:36 -07:00
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2008-01-01 10:23:02 -05:00
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2005-04-16 15:20:36 -07:00
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2010-09-15 13:08:27 +02:00
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2008-08-28 15:05:58 +09:00
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2010-09-15 13:08:27 +02:00
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2008-08-28 15:05:58 +09:00
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2005-04-16 15:20:36 -07:00
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2005-09-10 00:27:17 -07:00
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2005-04-16 15:20:36 -07:00
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2011-05-06 11:34:32 -06:00
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2005-04-16 15:20:36 -07:00
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2014-04-08 09:15:35 -06:00
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2014-04-08 09:17:40 -06:00
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2005-04-16 15:20:36 -07:00
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2010-04-01 15:01:41 -07:00
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2010-06-01 12:23:18 +02:00
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2010-04-01 15:01:41 -07:00
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2010-06-01 12:23:18 +02:00
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2010-04-01 15:01:41 -07:00
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2010-06-01 12:23:18 +02:00
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2010-04-01 15:01:41 -07:00
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2010-06-01 12:23:18 +02:00
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2010-04-01 15:01:41 -07:00
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2010-06-01 12:23:18 +02:00
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2010-04-01 15:01:41 -07:00
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2010-04-09 08:31:19 +02:00
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2010-04-01 15:01:41 -07:00
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2010-04-09 08:31:19 +02:00
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2010-04-01 15:01:41 -07:00
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2005-04-16 15:20:36 -07:00
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2008-06-30 20:04:41 +02:00
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2008-06-27 09:12:09 +02:00
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2008-06-30 20:04:41 +02:00
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2011-04-01 21:02:31 +02:00
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2008-06-30 20:04:41 +02:00
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2008-10-01 03:38:39 -04:00
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2010-09-10 20:50:10 +02:00
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2008-06-30 20:04:41 +02:00
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2008-10-02 12:53:22 +02:00
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2008-10-02 18:47:49 +02:00
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2008-06-30 20:04:41 +02:00
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2008-07-16 16:09:06 -04:00
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2008-06-30 20:04:41 +02:00
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2010-09-10 20:50:10 +02:00
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2008-06-30 20:04:41 +02:00
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2012-01-12 09:17:30 +01:00
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2008-06-30 20:04:41 +02:00
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2007-10-08 13:26:20 -04:00
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[PATCH] beginning of methods conversion
To keep the size of changesets sane we split the switch by drivers;
to keep the damn thing bisectable we do the following:
1) rename the affected methods, add ones with correct
prototypes, make (few) callers handle both. That's this changeset.
2) for each driver convert to new methods. *ALL* drivers
are converted in this series.
3) kill the old (renamed) methods.
Note that it _is_ a flagday; all in-tree drivers are converted and by the
end of this series no trace of old methods remain. The only reason why
we do that this way is to keep the damn thing bisectable and allow per-driver
debugging if anything goes wrong.
New methods:
open(bdev, mode)
release(disk, mode)
ioctl(bdev, mode, cmd, arg) /* Called without BKL */
compat_ioctl(bdev, mode, cmd, arg)
locked_ioctl(bdev, mode, cmd, arg) /* Called with BKL, legacy */
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-03-02 09:09:22 -05:00
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2013-05-05 21:52:57 -04:00
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2014-06-04 16:07:46 -07:00
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[PATCH] beginning of methods conversion
To keep the size of changesets sane we split the switch by drivers;
to keep the damn thing bisectable we do the following:
1) rename the affected methods, add ones with correct
prototypes, make (few) callers handle both. That's this changeset.
2) for each driver convert to new methods. *ALL* drivers
are converted in this series.
3) kill the old (renamed) methods.
Note that it _is_ a flagday; all in-tree drivers are converted and by the
end of this series no trace of old methods remain. The only reason why
we do that this way is to keep the damn thing bisectable and allow per-driver
debugging if anything goes wrong.
New methods:
open(bdev, mode)
release(disk, mode)
ioctl(bdev, mode, cmd, arg) /* Called without BKL */
compat_ioctl(bdev, mode, cmd, arg)
locked_ioctl(bdev, mode, cmd, arg) /* Called with BKL, legacy */
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-03-02 09:09:22 -05:00
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2007-10-08 13:26:20 -04:00
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implement in-kernel gendisk events handling
Currently, media presence polling for removeable block devices is done
from userland. There are several issues with this.
* Polling is done by periodically opening the device. For SCSI
devices, the command sequence generated by such action involves a
few different commands including TEST_UNIT_READY. This behavior,
while perfectly legal, is different from Windows which only issues
single command, GET_EVENT_STATUS_NOTIFICATION. Unfortunately, some
ATAPI devices lock up after being periodically queried such command
sequences.
* There is no reliable and unintrusive way for a userland program to
tell whether the target device is safe for media presence polling.
For example, polling for media presence during an on-going burning
session can make it fail. The polling program can avoid this by
opening the device with O_EXCL but then it risks making a valid
exclusive user of the device fail w/ -EBUSY.
* Userland polling is unnecessarily heavy and in-kernel implementation
is lighter and better coordinated (workqueue, timer slack).
This patch implements framework for in-kernel disk event handling,
which includes media presence polling.
* bdops->check_events() is added, which supercedes ->media_changed().
It should check whether there's any pending event and return if so.
Currently, two events are defined - DISK_EVENT_MEDIA_CHANGE and
DISK_EVENT_EJECT_REQUEST. ->check_events() is guaranteed not to be
called parallelly.
* gendisk->events and ->async_events are added. These should be
initialized by block driver before passing the device to add_disk().
The former contains the mask of all supported events and the latter
the mask of all events which the device can report without polling.
/sys/block/*/events[_async] export these to userland.
* Kernel parameter block.events_dfl_poll_msecs controls the system
polling interval (default is 0 which means disable) and
/sys/block/*/events_poll_msecs control polling intervals for
individual devices (default is -1 meaning use system setting). Note
that if a device can report all supported events asynchronously and
its polling interval isn't explicitly set, the device won't be
polled regardless of the system polling interval.
* If a device is opened exclusively with write access, event checking
is automatically disabled until all write exclusive accesses are
released.
* There are event 'clearing' events. For example, both of currently
defined events are cleared after the device has been successfully
opened. This information is passed to ->check_events() callback
using @clearing argument as a hint.
* Event checking is always performed from system_nrt_wq and timer
slack is set to 25% for polling.
* Nothing changes for drivers which implement ->media_changed() but
not ->check_events(). Going forward, all drivers will be converted
to ->check_events() and ->media_change() will be dropped.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-12-08 20:57:37 +01:00
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2007-10-08 13:26:20 -04:00
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2010-05-15 20:09:29 +02:00
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2007-10-08 13:26:20 -04:00
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2010-05-17 11:02:43 +05:30
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2007-10-08 13:26:20 -04:00
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2007-08-29 20:34:12 -04:00
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2014-06-04 16:07:46 -07:00
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[PATCH] BLOCK: Make it possible to disable the block layer [try #6]
Make it possible to disable the block layer. Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.
This patch does the following:
(*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
support.
(*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
an item that uses the block layer. This includes:
(*) Block I/O tracing.
(*) Disk partition code.
(*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.
(*) The SCSI layer. As far as I can tell, even SCSI chardevs use the
block layer to do scheduling. Some drivers that use SCSI facilities -
such as USB storage - end up disabled indirectly from this.
(*) Various block-based device drivers, such as IDE and the old CDROM
drivers.
(*) MTD blockdev handling and FTL.
(*) JFFS - which uses set_bdev_super(), something it could avoid doing by
taking a leaf out of JFFS2's book.
(*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is,
however, still used in places, and so is still available.
(*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
parts of linux/fs.h.
(*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.
(*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.
(*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
is not enabled.
(*) fs/no-block.c is created to hold out-of-line stubs and things that are
required when CONFIG_BLOCK is not set:
(*) Default blockdev file operations (to give error ENODEV on opening).
(*) Makes some /proc changes:
(*) /proc/devices does not list any blockdevs.
(*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.
(*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.
(*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
given command other than Q_SYNC or if a special device is specified.
(*) In init/do_mounts.c, no reference is made to the blockdev routines if
CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2.
(*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
error ENOSYS by way of cond_syscall if so).
(*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
CONFIG_BLOCK is not set, since they can't then happen.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:45:40 +02:00
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2014-06-04 16:06:27 -07:00
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|
[PATCH] BLOCK: Make it possible to disable the block layer [try #6]
Make it possible to disable the block layer. Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.
This patch does the following:
(*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
support.
(*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
an item that uses the block layer. This includes:
(*) Block I/O tracing.
(*) Disk partition code.
(*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.
(*) The SCSI layer. As far as I can tell, even SCSI chardevs use the
block layer to do scheduling. Some drivers that use SCSI facilities -
such as USB storage - end up disabled indirectly from this.
(*) Various block-based device drivers, such as IDE and the old CDROM
drivers.
(*) MTD blockdev handling and FTL.
(*) JFFS - which uses set_bdev_super(), something it could avoid doing by
taking a leaf out of JFFS2's book.
(*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is,
however, still used in places, and so is still available.
(*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
parts of linux/fs.h.
(*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.
(*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.
(*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
is not enabled.
(*) fs/no-block.c is created to hold out-of-line stubs and things that are
required when CONFIG_BLOCK is not set:
(*) Default blockdev file operations (to give error ENODEV on opening).
(*) Makes some /proc changes:
(*) /proc/devices does not list any blockdevs.
(*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.
(*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.
(*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
given command other than Q_SYNC or if a special device is specified.
(*) In init/do_mounts.c, no reference is made to the blockdev routines if
CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2.
(*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
error ENOSYS by way of cond_syscall if so).
(*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
CONFIG_BLOCK is not set, since they can't then happen.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:45:40 +02:00
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2011-03-11 20:17:08 +01:00
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2011-03-08 13:19:51 +01:00
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2011-03-11 20:17:08 +01:00
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2011-03-08 13:19:51 +01:00
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2011-03-11 20:17:08 +01:00
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2011-03-08 13:19:51 +01:00
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2011-04-16 13:27:55 +02:00
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2011-03-08 13:19:51 +01:00
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2014-06-04 16:06:27 -07:00
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|
[PATCH] BLOCK: Make it possible to disable the block layer [try #6]
Make it possible to disable the block layer. Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.
This patch does the following:
(*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
support.
(*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
an item that uses the block layer. This includes:
(*) Block I/O tracing.
(*) Disk partition code.
(*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.
(*) The SCSI layer. As far as I can tell, even SCSI chardevs use the
block layer to do scheduling. Some drivers that use SCSI facilities -
such as USB storage - end up disabled indirectly from this.
(*) Various block-based device drivers, such as IDE and the old CDROM
drivers.
(*) MTD blockdev handling and FTL.
(*) JFFS - which uses set_bdev_super(), something it could avoid doing by
taking a leaf out of JFFS2's book.
(*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is,
however, still used in places, and so is still available.
(*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
parts of linux/fs.h.
(*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.
(*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.
(*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
is not enabled.
(*) fs/no-block.c is created to hold out-of-line stubs and things that are
required when CONFIG_BLOCK is not set:
(*) Default blockdev file operations (to give error ENODEV on opening).
(*) Makes some /proc changes:
(*) /proc/devices does not list any blockdevs.
(*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.
(*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.
(*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
given command other than Q_SYNC or if a special device is specified.
(*) In init/do_mounts.c, no reference is made to the blockdev routines if
CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2.
(*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
error ENOSYS by way of cond_syscall if so).
(*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
CONFIG_BLOCK is not set, since they can't then happen.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:45:40 +02:00
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2005-04-16 15:20:36 -07:00
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