The code for trace events to format the raw recorded event data
into human readable format in the 'trace' file is repeated for every
event in the system. When you have over 500 events, this can add up
quite a bit.
By making helper functions in the core kernel to do the work
instead, we can shrink the size of the kernel down a bit.
With a kernel configured with 502 events, the change in size was:
text data bss dec hex filename
12991007 1913568 9785344 24689919 178bcff /tmp/vmlinux.orig
12990946 1913568 9785344 24689858 178bcc2 /tmp/vmlinux.patched
Note, this version does not save as much as the version of this patch
I had a few years ago. That is because in the mean time, commit
f71130de5c ("tracing: Add a helper function for event print functions")
did a lot of the work my original patch did. But this change helps
slightly, and is part of a larger clean up to reduce the size much further.
Link: http://lkml.kernel.org/r/20120810034707.378538034@goodmis.org
Cc: Li Zefan <lizefan@huawei.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Having ftrace_write() return -EPERM on failure, as that's what the callers
return, then we can clean up the code a bit. That is, instead of:
if (ftrace_write(...))
return -EPERM;
return 0;
or
if (ftrace_write(...)) {
ret = -EPERM;
goto_out;
}
We can instead have:
return ftrace_write(...);
or
ret = ftrace_write(...);
if (ret)
goto out;
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Support for Qualcomm Krait processors (run perf on your phone!)
* Support for Cortex-A12 (run perf stat on your FPGA!)
* Support for perf_sample_event_took, allowing us to automatically decrease
the sample rate if we can't handle the PMU interrupts quickly enough
(run perf record on your FPGA!).
As part of the Krait support, we also gain support for PPI generation by
the PMU.
The A31 Colombus board has 3 I2C controllers that should be usable. However,
the first one is not working for some reason on the hardware I have been able
to test it on, while it should really be the same controller. Enable the i2c1
and i2c2 busses, and mark i2c0 as in failure in the DT.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
The i2c controllers have a few muxing options on the A31. Enable the
ones found in the A31 Colombus board.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
The A31 has 4 I2C controllers that are the same than the one in the
other Allwinner SoCs, except for the fact that they are asserted in
reset by the reset unit.
Add these i2c controllers to the DTSI.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
The call to update_cpu_masks() from within topology_init()
is completely redundant. This patch removes it.
Signed-off-by: Philipp Hachtmann <phacht@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The whole compat exec domain code doesn't make any difference.
From the registered s390_exec_domain:
- exec domain name is only displayed in /proc/execdomains
- handler is unused
- pers_low and pers_high are only used internally to find this specific
exec domain otherwise the default exec domain will be used
- all other fields match the default exec domain
So let's get rid of this.
Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The unconditionally built keyboard driver, drivers/s390/char/keyboard.c,
requires CONFIG_TTY, so select it from CONFIG_S390 to prevent a build
error.
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
The cpu array size calculation uses the NR_CPUS config option, which
was recently increased from 64 to 256. With a value of 256, the cpu
array will no longer fit into one APPLDATA record and loading the
appldata_os module fails with the following error:
could not insert 'appldata_os': Cannot allocate memory
Use num_possible_cpus() instead of NR_CPUS. For z/VM, this will still
result in a value of 64. This is not true for LPAR, but the appldata
feature is not available for LPAR.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If x86-sysfb platform-devices are removed from a system, we should
properly unload vesafb. Otherwise, we end up releasing the parent while
our vesa framebuffer is still running. This currently works just fine, but
will cause problems on handover to real hw. So add the ->remove() callback
and unregister vesafb.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
If x86-sysfb platform-devices are removed from a system, we should
properly unload efifb. Otherwise, we end up releasing the parent while our
efi framebuffer is still running. This currently works just fine, but will
cause problems on handover to real hw. So add the ->remove() callback and
unregister efifb.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Switch to devres allocators to clean up the error unwinding paths.
Signed-off-by: Daniel Mack <zonque@gmail.com>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
This is necessary in order to make the core set file->private_data to
miscdev in use. We need that information later to dereference the
container of the device, so we can get access to our private struct from
other callbacks.
Signed-off-by: Daniel Mack <zonque@gmail.com>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Instead of passing around struct platform_device, use struct device.
That saves one level of dereference. Also, call platform devices pdev,
and provide a shortcut for &pdev->dev.
Signed-off-by: Daniel Mack <zonque@gmail.com>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Prefix some functions with more specific names. While at it, kill some
stray newlines and other coding style related minor things.
Signed-off-by: Daniel Mack <zonque@gmail.com>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
If we know that first N areas are all in use, we can obviously skip
them when searching for a free one. And that kind of hint is very
easy to maintain.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tejun Heo <tj@kernel.org>
Current code keeps +-length for each area in chunk->map[]. It has
several unpleasant consequences:
* even if we know that first 50 areas are all in use, allocation
still needs to go through all those areas just to sum their sizes, just
to get the offset of free one.
* freeing needs to find the array entry refering to the area
in question; again, the need to sum the sizes until we reach the offset
we are interested in. Note that offsets are monotonous, so simple
binary search would do here.
New data representation: array of <offset,in-use flag> pairs.
Each pair is represented by one int - we use offset|1 for <offset, in use>
and offset for <offset, free> (we make sure that all offsets are even).
In the end we put a sentry entry - <total size, in use>. The first
entry is <0, flag>; it would be possible to store together the flag
for Nth area and offset for N+1st, but that leads to much hairier code.
In other words, where the old variant would have
4, -8, -4, 4, -12, 100
(4 bytes free, 8 in use, 4 in use, 4 free, 12 in use, 100 free) we store
<0,0>, <4,1>, <12,1>, <16,0>, <20,1>, <32,0>, <132,1>
i.e.
0, 5, 13, 16, 21, 32, 133
This commit switches to new data representation and takes care of a couple
of low-hanging fruits in free_pcpu_area() - one is the switch to binary
search, another is not doing two memmove() when one would do. Speeding
the alloc side up (by keeping track of how many areas in the beginning are
known to be all in use) also becomes possible - that'll be done in the next
commit.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tejun Heo <tj@kernel.org>
... and simplify the results a bit. Makes the next step easier
to deal with - we will be changing the data representation for
chunk->map[] and it's easier to do if the code in question is
not split between pcpu_alloc_area() and pcpu_split_block().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tejun Heo <tj@kernel.org>
It uses the wrong mode index because there is no break statement.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
For some platforms, a poll state is inserted in the cpuidle driver states.
The flags for the state do not indicate that timekeeping is not affected.
As the state does not do anything apart from calling cpu_relax(), the
times returned by ktime_get should remain valid. Add the missing flag.
Signed-off-by: Tuukka Tikkanen <tuukka.tikkanen@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The hash set type is very broken and was never meant to be merged in this
state. Missing RCU synchronization on element removal, leaking chain
refcounts when used as a verdict map, races during lookups, a fixed table
size are probably just some of the problems. Luckily it is currently
never chosen by the kernel when the rbtree type is also available.
Rewrite it to be usable.
The new implementation supports automatic hash table resizing using RCU,
based on Paul McKenney's and Josh Triplett's algorithm "Optimized Resizing
For RCU-Protected Hash Tables" described in [1].
Resizing doesn't require a second list head in the elements, it works by
chosing a hash function that remaps elements to a predictable set of buckets,
only resizing by integral factors and
- during expansion: linking new buckets to the old bucket that contains
elements for any of the new buckets, thereby creating imprecise chains,
then incrementally seperating the elements until the new buckets only
contain elements that hash directly to them.
- during shrinking: linking the hash chains of all old buckets that hash
to the same new bucket to form a single chain.
Expansion requires at most the number of elements in the longest hash chain
grace periods, shrinking requires a single grace period.
Due to the requirement of having hash chains/elements linked to multiple
buckets during resizing, homemade single linked lists are used instead of
the existing list helpers, that don't support this in a clean fashion.
As a side effect, the amount of memory required per element is reduced by
one pointer.
Expansion is triggered when the load factors exceeds 75%, shrinking when
the load factor goes below 30%. Both operations are allowed to fail and
will be retried on the next insertion or removal if their respective
conditions still hold.
[1] http://dl.acm.org/citation.cfm?id=2002181.2002192
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_conntrack_lock is a monolithic lock and suffers from huge contention
on current generation servers (8 or more core/threads).
Perf locking congestion is clear on base kernel:
- 72.56% ksoftirqd/6 [kernel.kallsyms] [k] _raw_spin_lock_bh
- _raw_spin_lock_bh
+ 25.33% init_conntrack
+ 24.86% nf_ct_delete_from_lists
+ 24.62% __nf_conntrack_confirm
+ 24.38% destroy_conntrack
+ 0.70% tcp_packet
+ 2.21% ksoftirqd/6 [kernel.kallsyms] [k] fib_table_lookup
+ 1.15% ksoftirqd/6 [kernel.kallsyms] [k] __slab_free
+ 0.77% ksoftirqd/6 [kernel.kallsyms] [k] inet_getpeer
+ 0.70% ksoftirqd/6 [nf_conntrack] [k] nf_ct_delete
+ 0.55% ksoftirqd/6 [ip_tables] [k] ipt_do_table
This patch change conntrack locking and provides a huge performance
improvement. SYN-flood attack tested on a 24-core E5-2695v2(ES) with
10Gbit/s ixgbe (with tool trafgen):
Base kernel: 810.405 new conntrack/sec
After patch: 2.233.876 new conntrack/sec
Notice other floods attack (SYN+ACK or ACK) can easily be deflected using:
# iptables -A INPUT -m state --state INVALID -j DROP
# sysctl -w net/netfilter/nf_conntrack_tcp_loose=0
Use an array of hashed spinlocks to protect insertions/deletions of
conntracks into the hash table. 1024 spinlocks seem to give good
results, at minimal cost (4KB memory). Due to lockdep max depth,
1024 becomes 8 if CONFIG_LOCKDEP=y
The hash resize is a bit tricky, because we need to take all locks in
the array. A seqcount_t is used to synchronize the hash table users
with the resizing process.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Netfilter expectations are protected with the same lock as conntrack
entries (nf_conntrack_lock). This patch split out expectations locking
to use it's own lock (nf_conntrack_expect_lock).
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Preparation for disconnecting the nf_conntrack_lock from the
expectations code. Once the nf_conntrack_lock is lifted, a race
condition is exposed.
The expectations master conntrack exp->master, can race with
delete operations, as the refcnt increment happens too late in
init_conntrack(). Race is against other CPUs invoking
->destroy() (destroy_conntrack()), or nf_ct_delete() (via timeout
or early_drop()).
Avoid this race in nf_ct_find_expectation() by using atomic_inc_not_zero(),
and checking if nf_ct_is_dying() (path via nf_ct_delete()).
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
One spinlock per cpu to protect dying/unconfirmed/template special lists.
(These lists are now per cpu, a bit like the untracked ct)
Add a @cpu field to nf_conn, to make sure we hold the appropriate
spinlock at removal time.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Changes while reading through the netfilter code.
Added hint about how conntrack nf_conn refcnt is accessed.
And renamed repl_hash to reply_hash for readability
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Via Simon Horman:
====================
* Whitespace cleanup spotted by checkpatch.pl from Tingwei Liu.
* Section conflict cleanup, basically removal of one wrong __read_mostly,
from Andi Kleen.
====================
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
vprintk use is not prefixed by a KERN_<LEVEL>,
so emit these messages at KERN_ERR level.
Using %pV can save some code and allow fs_err to
be used, so do it.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Convert a couple of uses of pr_<level> to fs_<level>
Add and use fs_emerg.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Add pr_fmt, remove embedded "GFS2: " prefixes.
This now consistently emits lower case "gfs2: " for each message.
Other miscellanea around these changes:
o Add missing newlines
o Coalesce formats
o Realign arguments
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
If multiple nodes fail and their recovery work runs simultaneously, they
would use the same unprotected variables in the superblock. For example,
they would stomp on each other's revoked blocks lists, which resulted
in file system metadata corruption. This patch moves the necessary
variables so that each journal has its own separate area for tracking
its journal replay.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Additionally to have the second (data) bitrate available the data bitrate
has to be greater or equal to the arbitration bitrate in CAN FD.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The configuration for CAN FD depends on CAN_CTRLMODE_FD enabled in the driver
specific ctrlmode_supported capabilities.
The configuration can be done either with the 'fd { on | off }' option in the
'ip' tool from iproute2 or by setting the CAN netdevice MTU to CAN_MTU (16) or
to CANFD_MTU (72).
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
As CAN FD offers a second bitrate for the data section of the CAN frame the
infrastructure for storing and configuring this second bitrate is introduced.
Improved the readability of the if-statement by inserting some newlines.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
As the bittiming calculation functions are to be used with different
bittiming_const structures for CAN and CAN FD the direct reference to
priv->bittiming_const inside these functions has to be removed.
Also moved the check for existing bittiming const to one place.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch moves a sanity check in order to have a second user for CAN FD.
Also simplify the return value generation in can_get_bittiming() as only
correct return values of can_[calc|fixup]_bittiming() lead to a return value of
zero.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
When setting the bitrate both can_calc_bittiming() and can_fixup_bittiming()
lead to the bitrate variable to be set, when a proper bit timing is available.
Only then the bitrate configuration is stored for the device, so checking for
priv->bittiming.bitrate is always sufficient.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
The skbuff protocol value was formerly fixed/sanitized to ETH_P_CAN in
can_put_echo_skb(). With CAN FD this value has to be preserved.
This patch changes the hard assignment of the protocol value to a check of
valid protocol values for CAN and CAN FD.
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch converts the dev_<level> printing to netdev_<level>, this makes it
possible to remove the "struct device *dev" pointer from the "struct
ican3_dev".
Cc: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Seems like we have an old bug, where we incidently overwrites
the max_antenna_gain we pass to firmware, with zero value.
End of all we are artifically reducing the output power.
This patch removes the excessive assignment on max_antenna_gain,
which is being provided by regulatory domain, and consequently
improves the tx power.
Signed-off-by: Marek Puzyniak <marek.puzyniak@tieto.com>
Signed-off-by: Bartosz Markowski <bartosz.markowski@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Consolidate the list of msdu skbs into the msdu-head skb, delete the
rest of the skbs, pass the msdu-head skb on up the stack as normal.
Tested with high-speed TCP and UDP traffic on modified firmware that
supports raw-rx.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Lenovo IdeaPad 410Y with ALC282 codec makes loud click noises at boot
and shutdown. Also, it wrongly misdetects the acpi_thinkpad hook.
This patch adds a device-specific fixup for disabling the shutup
callback that is the cause of the click noise and also avoiding the
thinpad_helper calls.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=71511
Reported-and-tested-by: Guilherme Amadio <guilherme.amadio@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
iproute2 already defines a structure with that name, let's use another one to
avoid any conflict.
CC: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
This is required since commit 2025172e32 "spi/bitbang: Use core message pump".
spi-bitbang now uses core message pump, so it needs to call spi_master_suspend/
spi_master_resume to start/stop the queue while suspend/resume.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Back in commit 23956703 ("xfs: inode log reservations are too
small"), the reservation size was increased to take into account the
difference in size between the in-memory BMBT block headers and the
on-disk BMDR headers. This solved a transaction overrun when logging
the inode size.
Recently, however, we've seen a number of these same overruns on
kernels with the above fix in it. All of them have been by 4 bytes,
so we must still not be accounting for something correctly.
Through inspection it turns out the above commit didn't take into
account everything it should have. That is, it only accounts for a
single log op_hdr structure, when it can actually require up to four
op_hdrs - one for each region (log iovec) that is formatted. These
regions are the inode log format header, the inode core, and the two
forks that can be held in the literal area of the inode.
This means we are not accounting for 36 bytes of log space that the
transaction can use, and hence when we get inodes in certain formats
with particular fragmentation patterns we can overrun the
transaction. Fix this by adding the correct accounting for log
op_headers in the transaction.
Tested-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
xfs_aops_discard_page() was introduced in the following commit:
xfs: truncate delalloc extents when IO fails in writeback
... to clean up left over delalloc ranges after I/O failure in
->writepage(). generic/224 tests for this scenario and occasionally
reproduces panics on sub-4k blocksize filesystems.
The cause of this is failure to clean up the delalloc range on a
page where the first buffer does not match one of the expected
states of xfs_check_page_type(). If a buffer is not unwritten,
delayed or dirty&mapped, xfs_check_page_type() stops and
immediately returns 0.
The stress test of generic/224 creates a scenario where the first
several buffers of a page with delayed buffers are mapped & uptodate
and some subsequent buffer is delayed. If the ->writepage() happens
to fail for this page, xfs_aops_discard_page() incorrectly skips
the entire page.
This then causes later failures either when direct IO maps the range
and finds the stale delayed buffer, or we evict the inode and find
that the inode still has a delayed block reservation accounted to
it.
We can easily fix this xfs_aops_discard_page() failure by making
xfs_check_page_type() check all buffers, but this breaks
xfs_convert_page() more than it is already broken. Indeed,
xfs_convert_page() wants xfs_check_page_type() to tell it if the
first buffers on the pages are of a type that can be aggregated into
the contiguous IO that is already being built.
xfs_convert_page() should not be writing random buffers out of a
page, but the current behaviour will cause it to do so if there are
buffers that don't match the current specification on the page.
Hence for xfs_convert_page() we need to:
a) return "not ok" if the first buffer on the page does not
match the specification provided to we don't write anything;
and
b) abort it's buffer-add-to-io loop the moment we come
across a buffer that does not match the specification.
Hence we need to fix both xfs_check_page_type() and
xfs_convert_page() to work correctly with pages that have mixed
buffer types, whilst allowing xfs_aops_discard_page() to scan all
buffers on the page for a type match.
Reported-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
The inode chunk allocation path can lead to deadlock conditions if
a transaction is dirtied with an AGF (to fix up the freelist) for
an AG that cannot satisfy the actual allocation request. This code
path is written to try and avoid this scenario, but it can be
reproduced by running xfstests generic/270 in a loop on a 512b fs.
An example situation is:
- process A attempts an inode allocation on AG 3, modifies
the freelist, fails the allocation and ultimately moves on to
AG 0 with the AG 3 AGF held
- process B is doing a free space operation (i.e., truncate) and
acquires the AG 0 AGF, waits on the AG 3 AGF
- process A acquires the AG 0 AGI, waits on the AG 0 AGF (deadlock)
The problem here is that process A acquired the AG 3 AGF while
moving on to AG 0 (and releasing the AG 3 AGI with the AG 3 AGF
held). xfs_dialloc() makes one pass through each of the AGs when
attempting to allocate an inode chunk. The expectation is a clean
transaction if a particular AG cannot satisfy the allocation
request. xfs_ialloc_ag_alloc() is written to support this through
use of the minalignslop allocation args field.
When using the agi->agi_newino optimization, we attempt an exact
bno allocation request based on the location of the previously
allocated chunk. minalignslop is set to inform the allocator that
we will require alignment on this chunk, and thus to not allow the
request for this AG if the extra space is not available. Suppose
that the AG in question has just enough space for this request, but
not at the requested bno. xfs_alloc_fix_freelist() will proceed as
normal as it determines the request should succeed, and thus it is
allowed to modify the agf. xfs_alloc_ag_vextent() ultimately fails
because the requested bno is not available. In response, the caller
moves on to a NEAR_BNO allocation request for the same AG. The
alignment is set, but the minalignslop field is never reset. This
increases the overall requirement of the request from the first
attempt. If this delta is the difference between allocation success
and failure for the AG, xfs_alloc_fix_freelist() rejects this
request outright the second time around and causes the allocation
request to unnecessarily fail for this AG.
To address this situation, reset the minalignslop field immediately
after use and prevent it from leaking into subsequent requests.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
When we map pages in the buffer cache, we can do so in GFP_NOFS
contexts. However, the vmap interfaces do not provide any method of
communicating this information to memory reclaim, and hence we get
lockdep complaining about it regularly and occassionally see hangs
that may be vmap related reclaim deadlocks. We can also see these
same problems from anywhere where we use vmalloc for a large buffer
(e.g. attribute code) inside a transaction context.
A typical lockdep report shows up as a reclaim state warning like so:
[14046.101458] =================================
[14046.102850] [ INFO: inconsistent lock state ]
[14046.102850] 3.14.0-rc4+ #2 Not tainted
[14046.102850] ---------------------------------
[14046.102850] inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage.
[14046.102850] kswapd0/14 [HC0[0]:SC0[0]:HE1:SE1] takes:
[14046.102850] (&xfs_dir_ilock_class){++++?+}, at: [<791a04bb>] xfs_ilock+0xff/0x16a
[14046.102850] {RECLAIM_FS-ON-W} state was registered at:
[14046.102850] [<7904cdb1>] mark_held_locks+0x81/0xe7
[14046.102850] [<7904d390>] lockdep_trace_alloc+0x5c/0xb4
[14046.102850] [<790c2c28>] kmem_cache_alloc_trace+0x2b/0x11e
[14046.102850] [<790ba7f4>] vm_map_ram+0x119/0x3e6
[14046.102850] [<7914e124>] _xfs_buf_map_pages+0x5b/0xcf
[14046.102850] [<7914ed74>] xfs_buf_get_map+0x67/0x13f
[14046.102850] [<7917506f>] xfs_attr_rmtval_set+0x396/0x4d5
[14046.102850] [<7916e8bb>] xfs_attr_leaf_addname+0x18f/0x37d
[14046.102850] [<7916ed9e>] xfs_attr_set_int+0x2f5/0x3e8
[14046.102850] [<7916eefc>] xfs_attr_set+0x6b/0x74
[14046.102850] [<79168355>] xfs_xattr_set+0x61/0x81
[14046.102850] [<790e5b10>] generic_setxattr+0x59/0x68
[14046.102850] [<790e4c06>] __vfs_setxattr_noperm+0x58/0xce
[14046.102850] [<790e4d0a>] vfs_setxattr+0x8e/0x92
[14046.102850] [<790e4ddd>] setxattr+0xcf/0x159
[14046.102850] [<790e5423>] SyS_lsetxattr+0x88/0xbb
[14046.102850] [<79268438>] sysenter_do_call+0x12/0x36
Now, we can't completely remove these traces - mainly because
vm_map_ram() will do GFP_KERNEL allocation and that generates the
above warning before we get into the reclaim code, but we can turn
them all into false positive warnings.
To do that, use the method that DM and other IO context code uses to
avoid this problem: there is a process flag to tell memory reclaim
not to do IO that we can set appropriately. That prevents GFP_KERNEL
context reclaim being done from deep inside the vmalloc code in
places we can't directly pass a GFP_NOFS context to. That interface
has a pair of wrapper functions: memalloc_noio_save() and
memalloc_noio_restore().
Adding them around vm_map_ram and the vzalloc call in
kmem_alloc_large() will prevent deadlocks and most lockdep reports
for this issue. Also, convert the vzalloc() call in
kmem_alloc_large() to use __vmalloc() so that we can pass the
correct gfp context to the data page allocation routine inside
__vmalloc() so that it is clear that GFP_NOFS context is important
to this vmalloc call.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
