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287,753 commits

Author SHA1 Message Date
Steven Rostedt
762e120788 tracing: Have stack tracing set filtered functions at boot
Add stacktrace_filter= to the kernel command line that lets
the user pick specific functions to check the stack on.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:26:49 -05:00
Steven Rostedt
2a85a37f16 ftrace: Allow access to the boot time function enabling
Change set_ftrace_early_filter() to ftrace_set_early_filter()
and make it a global function. This will allow other subsystems
in the kernel to be able to enable function tracing at start
up and reuse the ftrace function parsing code.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:26:35 -05:00
Steven Rostedt
d2d45c7a03 tracing: Have stack_tracer use a separate list of functions
The stack_tracer is used to look at every function and check
if the current stack is bigger than the last recorded max stack size.
When a new max is found, then it saves that stack off.

Currently the stack tracer is limited by the global_ops of
the function tracer. As the stack tracer has nothing to do with
the ftrace function tracer, except that it uses it as its internal
engine, the stack tracer should have its own list.

A new file is added to the tracing debugfs directory called:

  stack_trace_filter

that can be used to select which functions you want to check the stack
on.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:25:57 -05:00
Steven Rostedt
69a3083c4a ftrace: Decouple hash items from showing filtered functions
The set_ftrace_filter shows "hashed" functions, which are functions
that are added with operations to them (like traceon and traceoff).

As other subsystems may be able to show what functions they are
using for function tracing, the hash items should no longer
be shown just because the FILTER flag is set. As they have nothing
to do with other subsystems filters.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:25:24 -05:00
Steven Rostedt
fc13cb0ce4 ftrace: Allow other users of function tracing to use the output listing
The function tracer is set up to allow any other subsystem (like perf)
to use it. Ftrace already has a way to list what functions are enabled
by the global_ops. It would be very helpful to let other users of
the function tracer to be able to use the same code.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:25:06 -05:00
Steven Rostedt
06a51d9307 ftrace: Create ftrace_hash_empty() helper routine
There are two types of hashes in the ftrace_ops; one type
is the filter_hash and the other is the notrace_hash. Either
one may be null, meaning it has no elements. But when elements
are added, the hash is allocated.

Throughout the code, a check needs to be made to see if a hash
exists or the hash has elements, but the check if the hash exists
is usually missing causing the possible "NULL pointer dereference bug".

Add a helper routine called "ftrace_hash_empty()" that returns
true if the hash doesn't exist or its count is zero. As they mean
the same thing.

Last-bug-reported-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:23:11 -05:00
Steven Rostedt
c842e97552 ftrace: Fix ftrace hash record update with notrace
When disabling the "notrace" records, that means we want to trace them.
If the notrace_hash is zero, it means that we want to trace all
records. But to disable a zero notrace_hash means nothing.

The check for the notrace_hash count was incorrect with:

	if (hash && !hash->count)
		return

With the correct comment above it that states that we do nothing
if the notrace_hash has zero count. But !hash also means that
the notrace hash has zero count. I think this was done to
protect against dereferencing NULL. But if !hash is true, then
we go through the following loop without doing a single thing.

Fix it to:

	if (!hash || !hash->count)
		return;

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:21:43 -05:00
Steven Rostedt
5855fead9c ftrace: Use bsearch to find record ip
Now that each set of pages in the function list are sorted by
ip, we can use bsearch to find a record within each set of pages.
This speeds up the ftrace_location() function by magnitudes.

For archs (like x86) that need to add a breakpoint at every function
that will be converted from a nop to a callback and vice versa,
the breakpoint callback needs to know if the breakpoint was for
ftrace or not. It requires finding the breakpoint ip within the
records. Doing a linear search is extremely inefficient. It is
a must to be able to do a fast binary search to find these locations.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:20:50 -05:00
Steven Rostedt
68950619f8 ftrace: Sort the mcount records on each page
Sort records by ip locations of the ftrace mcount calls on each of the
set of pages in the function list. This helps in localizing cache
usuage when updating the function locations, as well as gives us
the ability to quickly find an ip location in the list.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:19:58 -05:00
Steven Rostedt
85ae32ae01 ftrace: Replace record newlist with record page list
As new functions come in to be initalized from mcount to nop,
they are done by groups of pages. Whether it is the core kernel
or a module. There's no need to keep track of these on a per record
basis.

At startup, and as any module is loaded, the functions to be
traced are stored in a group of pages and added to the function
list at the end. We just need to keep a pointer to the first
page of the list that was added, and use that to know where to
start on the list for initializing functions.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:19:03 -05:00
Steven Rostedt
a790087554 ftrace: Allocate the mcount record pages as groups
Allocate the mcount record pages as a group of pages as big
as can be allocated and waste no more than a single page.

Grouping the mcount pages as much as possible helps with cache
locality, as we do not need to redirect with descriptors as we
cross from page to page. It also allows us to do more with the
records later on (sort them with bigger benefits).

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:18:30 -05:00
Steven Rostedt
3208230983 ftrace: Remove usage of "freed" records
Records that are added to the function trace table are
permanently there, except for modules. By separating out the
modules to their own pages that can be freed in one shot
we can remove the "freed" flag and simplify some of the record
management.

Another benefit of doing this is that we can also move the
records around; sort them.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:17:57 -05:00
Steven Rostedt
c88fd8634e ftrace: Allow archs to modify code without stop machine
The stop machine method to modify all functions in the kernel
(some 20,000 of them) is the safest way to do so across all archs.
But some archs may not need this big hammer approach to modify code
on SMP machines, and can simply just update the code it needs.

Adding a weak function arch_ftrace_update_code() that now does the
stop machine, will also let any arch override this method.

If the arch needs to check the system and then decide if it can
avoid stop machine, it can still call ftrace_run_stop_machine() to
use the old method.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:16:58 -05:00
Steven Rostedt
45959ee7aa ftrace: Do not function trace inlined functions
When gcc inlines a function, it does not mark it with the mcount
prologue, which in turn means that inlined functions are not traced
by the function tracer. But if CONFIG_OPTIMIZE_INLINING is set, then
gcc is allowed not to inline a function that is marked inline.

Depending on the options and the compiler, a function may or may
not be traced by the function tracer, depending on whether gcc
decides to inline a function or not. This has caused several
problems in the pass becaues gcc is not always consistent with
what it decides to inline between different gcc versions.

Some places should not be traced (like paravirt native_* functions)
and these are mostly marked as inline. When gcc decides not to
inline the function, and if that function should not be traced, then
the ftrace function tracer will suddenly break when it use to work
fine. This becomes even harder to debug when different versions of
gcc will not inline that function, making the same kernel and config
work for some gcc versions and not work for others.

By making all functions marked inline to not be traced will remove
the ambiguity that gcc adds when it comes to tracing functions marked
inline. All gcc versions will be consistent with what functions are
traced and having volatile working code will be removed.

Note, only the inline macro when CONFIG_OPTIMIZE_INLINING is set needs
to have notrace added, as the attribute __always_inline will force
the function to be inlined and then not traced.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:14:34 -05:00
Jiri Olsa
30fb6aa740 ftrace: Fix unregister ftrace_ops accounting
Multiple users of the function tracer can register their functions
with the ftrace_ops structure. The accounting within ftrace will
update the counter on each function record that is being traced.
When the ftrace_ops filtering adds or removes functions, the
function records will be updated accordingly if the ftrace_ops is
still registered.

When a ftrace_ops is removed, the counter of the function records,
that the ftrace_ops traces, are decremented. When they reach zero
the functions that they represent are modified to stop calling the
mcount code.

When changes are made, the code is updated via stop_machine() with
a command passed to the function to tell it what to do. There is an
ENABLE and DISABLE command that tells the called function to enable
or disable the functions. But the ENABLE is really a misnomer as it
should just update the records, as records that have been enabled
and now have a count of zero should be disabled.

The DISABLE command is used to disable all functions regardless of
their counter values. This is the big off switch and is not the
complement of the ENABLE command.

To make matters worse, when a ftrace_ops is unregistered and there
is another ftrace_ops registered, neither the DISABLE nor the
ENABLE command are set when calling into the stop_machine() function
and the records will not be updated to match their counter. A command
is passed to that function that will update the mcount code to call
the registered callback directly if it is the only one left. This
means that the ftrace_ops that is still registered will have its callback
called by all functions that have been set for it as well as the ftrace_ops
that was just unregistered.

Here's a way to trigger this bug. Compile the kernel with
CONFIG_FUNCTION_PROFILER set and with CONFIG_FUNCTION_GRAPH not set:

 CONFIG_FUNCTION_PROFILER=y
 # CONFIG_FUNCTION_GRAPH is not set

This will force the function profiler to use the function tracer instead
of the function graph tracer.

  # cd /sys/kernel/debug/tracing
  # echo schedule > set_ftrace_filter
  # echo function > current_tracer
  # cat set_ftrace_filter
 schedule
  # cat trace
 # tracer: nop
 #
 # entries-in-buffer/entries-written: 692/68108025   #P:4
 #
 #                              _-----=> irqs-off
 #                             / _----=> need-resched
 #                            | / _---=> hardirq/softirq
 #                            || / _--=> preempt-depth
 #                            ||| /     delay
 #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
 #              | |       |   ||||       |         |
      kworker/0:2-909   [000] ....   531.235574: schedule <-worker_thread
           <idle>-0     [001] .N..   531.235575: schedule <-cpu_idle
      kworker/0:2-909   [000] ....   531.235597: schedule <-worker_thread
             sshd-2563  [001] ....   531.235647: schedule <-schedule_hrtimeout_range_clock

  # echo 1 > function_profile_enabled
  # echo 0 > function_porfile_enabled
  # cat set_ftrace_filter
 schedule
  # cat trace
 # tracer: function
 #
 # entries-in-buffer/entries-written: 159701/118821262   #P:4
 #
 #                              _-----=> irqs-off
 #                             / _----=> need-resched
 #                            | / _---=> hardirq/softirq
 #                            || / _--=> preempt-depth
 #                            ||| /     delay
 #           TASK-PID   CPU#  ||||    TIMESTAMP  FUNCTION
 #              | |       |   ||||       |         |
           <idle>-0     [002] ...1   604.870655: local_touch_nmi <-cpu_idle
           <idle>-0     [002] d..1   604.870655: enter_idle <-cpu_idle
           <idle>-0     [002] d..1   604.870656: atomic_notifier_call_chain <-enter_idle
           <idle>-0     [002] d..1   604.870656: __atomic_notifier_call_chain <-atomic_notifier_call_chain

The same problem could have happened with the trace_probe_ops,
but they are modified with the set_frace_filter file which does the
update at closure of the file.

The simple solution is to change ENABLE to UPDATE and call it every
time an ftrace_ops is unregistered.

Link: http://lkml.kernel.org/r/1323105776-26961-3-git-send-email-jolsa@redhat.com

Cc: stable@vger.kernel.org # 3.0+
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:09:14 -05:00
Felipe Balbi
eeb720fb21 usb: dwc3: gadget: add support for SG lists
add support for SG lists on dwc3 driver. With
this we can e.g. use VFS layer's SG lists on
storage gadgets so that we can start bigger
transfers and improve throughput.

Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:24:46 +02:00
Felipe Balbi
42f8eb7a10 usb: dwc3: gadget: don't force 'LST' always
the LST bit is to be set on the last of a series
of consecutive TRBs. We had a workaround for a
problem where data would get corrupted but that
doesn't happen anymore. It's likely that it was
caused by some FPGA instability during development
phase.

Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:24:46 +02:00
Felipe Balbi
68e823e24a usb: dwc3: gadget: don't return anything on prepare trbs
all that function does is setup a TRB to be sent
to HW later. There's no need to return anything
actually.

Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:24:45 +02:00
Felipe Balbi
c71fc37c19 usb: dwc3: gadget: re-factor dwc3_prepare_trbs()
In order to make it easier to add SG support,
let's split the big loop out to its own function.

Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:24:45 +02:00
Felipe Balbi
898c608678 usb: gadget: introduce support for sg lists
Some controllers support scatter/gather transfers
and that might be very useful for some gadget drivers.

This means that we can make use of larger buffer
allocations which means we will have less completion
IRQs overtime, thus improving the perceived performance.

Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:24:44 +02:00
Felipe Balbi
14ff96e04c usb: renesas: pipe: convert a long if into a XOR operation
This is just a minor optimization for the long
if we have on the driver.

When we want to check that one input is true
and the other must be false, the bitwise XOR
operator will achieve that for us.

Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:24:43 +02:00
Felipe Contreras
abfbe33410 usb: gadget: remove useless depends on Kconfig
Where are inside an 'if USB_GADGET'.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:24:43 +02:00
Heiko Stübner
922be95a3f usb: gadget: s3c-hsudc: remove the_controller global
Instead use container_of to retrieve the s3c_hsudc from the
struct usb_gadget pointer.

[ balbi@ti.com : changed verbose container_of() into
	an already provided helper 'to_hsudc()' ]

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:24:42 +02:00
Heiko Stübner
dee19be7d8 usb: gadget: s3c-hsudc: use release_mem_region instead of release_resource
As the memory region is requested through request_mem_region
use the correct paired method to release it in the error path
and don't go "beneath the API".

Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:24:41 +02:00
Heiko Stübner
bab7d037c8 usb: gadget: s3c-hsudc: Add regulator handling
The udc has three supplies: vdda (3.3V), vddi (1.2V) and vddosc (1.8-3.3V).
Turn these on and off on start and stop calls.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:24:40 +02:00
Heiko Stübner
d93e2600d8 usb: gadget: s3c-hsudc: use udc_start and udc_stop functions
udc_start and udc_stop reduce code duplication in comparison to
start and stop generalising calls done by all drivers
(i.e. bind and unbind) and moving these calls to common code.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:24:39 +02:00
Heiko Stübner
103495aaf0 usb: gadget: s3c-hsudc: move device registration to probe
Instead of adding and deleting the gadget device in the start and stop
invocations. Use device_register in the probe method to initialize
and add the gadget device.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:24:39 +02:00
Heiko Stübner
e9bcb9e5fe usb: gadget: s3c-hsudc: add missing otg_put_transceiver in probe
The number of get and put calls should always be equal.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:24:38 +02:00
Heiko Stübner
a197756271 usb: gadget: s3c-hsudc: add __devinit to probe function
Fixes possible section mismatch warnings.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:24:37 +02:00
Heiko Stübner
715a3e41e7 usb: gadget: s3c-hsudc: move platform_data struct to global header
Gadget drivers should be compilable on all architectures.
This patch removes one dependency on architecture-specific code.

Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:24:27 +02:00
Vladimir Zapolskiy
b0945c07d9 usb: musb: remove extern qualifier from musb_debug.h header
This change removes confusing extern qualifier, which doesn't have any practical
sense there.

Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@nokia.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2011-12-21 13:21:02 +02:00
Daniel Kurtz
4371ea8202 HID: usbhid: defer LED setting to a workqueue
Defer LED setting action to a workqueue.
This is more likely to send all LED change events in a single URB.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Acked-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-12-21 11:18:35 +01:00
Daniel Kurtz
f0befcd64b HID: usbhid: hid-core: submit queued urbs before suspend
If any userspace program has opened a keyboard device, the input core
de-activates the keyboard's LEDs upon suspend().  It does this by sending
individual EV_LED[LED_X]=0 events to the underlying device driver by
directly calling the driver's registered event() handler.

The usb-hid driver event() handler processes each request by immediately
attempting to submit a CTRL URB to turn off the LED.  USB URB submission
is asynchronous.  First the URB is added to the head of the ctrl queue.
Then, if the CTRL_RUNNING flag is false, the URB is submitted immediately
(and CTRL_RUNNING is set).  If the CTRL_RUNNING flag was already true,
then the newly queued URB is submitted in the ctrl completion handler when
all previously submitted URBs have completed.  When all queued URBs have
been submitted, the completion handler clears the CTRL_RUNNING flag.

In the 2-LED suspend case, at input suspend(), 2 LED event CTRL URBs get
queued, with only the first actually submitted.  Soon after input
suspend() handler finishes, the usb-hid suspend() handler gets called.
Since this is NOT a PM_EVENT_AUTO suspend, the handler sets
REPORTED_IDLE, then waits for io to complete.

Unfortunately, this usually happens while the first LED request is
actually still being processed.  Thus when the completion handler tries
to submit the second LED request it fails, since REPORTED_IDLE is
already set!  This REPORTED_IDLE check failure causes the completion
handler to complete, however without clearing the CTRL_RUNNING flag.
This, in turn, means that the suspend() handler's wait_io() condition
is never satisfied, and instead it times out after 10 seconds, aborting
the original system suspend.

This patch changes the behavior to the following:
  (1) allow completion handler to finish submitting all queued URBs, even if
      REPORTED_IDLE is set.  This guarantees that all URBs queued before the
      hid-core suspend() call will be submitted before the system is
      suspended.
  (2) if REPORTED_IDLE is set and the URB queue is empty, queue, but
      don't submit, new URB submission requests.  These queued requests get
      submitted when resume() flushes the URB queue. This is similar to the
      existing behavior, however, any requests that arrive while the queue is
      not yet empty will still get submitted before suspend.
  (3) set the RUNNING flag when flushing the URB queue in resume().
      This keeps URBs that were queued in (2) from colliding with any new
      URBs that are being submitted during the resume process.  The new URB
      submission requests upon resume get properly queued behind the ones
      being flushed instead of the current situation where they collide,
      causing memory corruption and oopses.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Acked-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-12-21 11:18:35 +01:00
Daniel Kurtz
ede6a8b239 HID: usbhid: remove LED_ON
LED_ON was defined in the original version of the hid-core autosuspend patch.
However, during review, the setting and clearing of it was redone
using ledcount.  The test was left in accidentally.

Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Acked-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-12-21 11:18:35 +01:00
Dave Airlie
4cf73129cb Merge remote-tracking branch 'pfdo/drm-fixes' into drm-core-next
-next reported a messy merge, so I've merged my upstream pull into
my -next tree.

Conflicts:
	drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
2011-12-21 09:50:56 +00:00
Daisuke Nishimura
62af3783e4 sched: Fix cgroup movement of waking process
There is a small race between try_to_wake_up() and sched_move_task(),
which is trying to move the process being woken up.

    try_to_wake_up() on CPU0       sched_move_task() on CPU1
--------------------------------+---------------------------------
  raw_spin_lock_irqsave(p->pi_lock)
  task_waking_fair()
    ->p.se.vruntime -= cfs_rq->min_vruntime
  ttwu_queue()
    ->send reschedule IPI to CPU1
  raw_spin_unlock_irqsave(p->pi_lock)
                                   task_rq_lock()
                                     -> tring to aquire both p->pi_lock and
                                        rq->lock with IRQ disabled
                                   task_move_group_fair()
                                     -> p.se.vruntime
                                          -= (old)cfs_rq->min_vruntime
                                          += (new)cfs_rq->min_vruntime
                                   task_rq_unlock()

                                   (via IPI)
                                   sched_ttwu_pending()
                                     raw_spin_lock(rq->lock)
                                     ttwu_do_activate()
                                       ...
                                       enqueue_entity()
                                         child.se->vruntime += cfs_rq->min_vruntime
                                     raw_spin_unlock(rq->lock)

As a result, vruntime of the process becomes far bigger than min_vruntime,
if (new)cfs_rq->min_vruntime >> (old)cfs_rq->min_vruntime.

This patch fixes this problem by just ignoring such process in
task_move_group_fair(), because the vruntime has already been normalized in
task_waking_fair().

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20111215143741.df82dd50.nishimura@mxp.nes.nec.co.jp
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:34:52 +01:00
Daisuke Nishimura
7ceff013c4 sched: Fix cgroup movement of newly created process
There is a small race between do_fork() and sched_move_task(), which is
trying to move the child.

            do_fork()                 sched_move_task()
--------------------------------+---------------------------------
  copy_process()
    sched_fork()
      task_fork_fair()
        -> vruntime of the child is initialized
           based on that of the parent.
  -> we can see the child in "tasks" file now.
                                    task_rq_lock()
                                    task_move_group_fair()
                                      -> child.se.vruntime
                                           -= (old)cfs_rq->min_vruntime
                                           += (new)cfs_rq->min_vruntime
                                    task_rq_unlock()
  wake_up_new_task()
    ...
    enqueue_entity()
      child.se.vruntime += cfs_rq->min_vruntime

As a result, vruntime of the child becomes far bigger than min_vruntime,
if (new)cfs_rq->min_vruntime >> (old)cfs_rq->min_vruntime.

This patch fixes this problem by just ignoring such process in
task_move_group_fair(), because the vruntime has already been normalized in
task_fork_fair().

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20111215143607.2ee12c5d.nishimura@mxp.nes.nec.co.jp
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:34:51 +01:00
Daisuke Nishimura
4fc420c91f sched: Fix cgroup movement of forking process
There is a small race between task_fork_fair() and sched_move_task(),
which is trying to move the parent.

        task_fork_fair()                 sched_move_task()
--------------------------------+---------------------------------
  cfs_rq = task_cfs_rq(current)
    -> cfs_rq is the "old" one.
  curr = cfs_rq->curr
    -> curr is set to the parent.
                                    task_rq_lock()
                                    dequeue_task()
                                      ->parent.se.vruntime -= (old)cfs_rq->min_vruntime
                                    enqueue_task()
                                      ->parent.se.vruntime += (new)cfs_rq->min_vruntime
                                    task_rq_unlock()
  raw_spin_lock_irqsave(rq->lock)
  se->vruntime = curr->vruntime
    -> vruntime of the child is set to that of the parent
       which has already been updated by sched_move_task().
  se->vruntime -= (old)cfs_rq->min_vruntime.
  raw_spin_unlock_irqrestore(rq->lock)

As a result, vruntime of the child becomes far bigger than expected,
if (new)cfs_rq->min_vruntime >> (old)cfs_rq->min_vruntime.

This patch fixes this problem by setting "cfs_rq" and "curr" after
holding the rq->lock.

Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Tejun Heo <tj@kernel.org>
Link: http://lkml.kernel.org/r/20111215143655.662676b0.nishimura@mxp.nes.nec.co.jp
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:34:49 +01:00
Kamalesh Babulal
11534ec5b6 sched: Remove cfs bandwidth period check in tg_set_cfs_period()
Remove cfs bandwidth period check from tg_set_cfs_period.
Invalid bandwidth period's lower/upper limits are denoted
by min_cfs_quota_period/max_cfs_quota_period repsectively,
and are checked against valid period in tg_set_cfs_bandwidth().

As pjt pointed out, negative input will result in very large unsigned
numbers and will be caught by the max allowed period test.

Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Acked-by: Paul Turner <pjt@google.com>
[ammended changelog to mention negative values]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20111210135925.GA14593@linux.vnet.ibm.com
--
 kernel/sched/core.c |    3 ---
 1 file changed, 3 deletions(-)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:34:48 +01:00
Peter Zijlstra
a195f004e9 sched: Fix load-balance lock-breaking
The current lock break relies on contention on the rq locks, something
which might never come because we've got IRQs disabled. Or will be
very likely because on anything with more than 2 cpus a synchronized
load-balance pass will very likely cause contention on the rq locks.

Also the sched_nr_migrate thing fails when it gets trapped the loops
of either the cgroup muck in load_balance_fair() or the move_tasks()
load condition.

Instead, use the new lb_flags field to propagate break/abort
conditions for all these loops and create a new loop outside the irq
disabled on the break being required.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-tsceb6w61q0gakmsccix6xxi@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:34:47 +01:00
Peter Zijlstra
5b54b56be5 sched: Replace all_pinned with a generic flags field
Replace the all_pinned argument with a flags field so that we can add
some extra controls throughout that entire call chain.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-33kevm71m924ok1gpxd720v3@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:34:45 +01:00
Peter Zijlstra
518cd62341 sched: Only queue remote wakeups when crossing cache boundaries
Mike reported a 13% drop in netperf TCP_RR performance due to the
new remote wakeup code. Suresh too noticed some performance issues
with it.

Reducing the IPIs to only cross cache domains solves the observed
performance issues.

Reported-by: Suresh Siddha <suresh.b.siddha@intel.com>
Reported-by: Mike Galbraith <efault@gmx.de>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Dave Kleikamp <dave.kleikamp@oracle.com>
Link: http://lkml.kernel.org/r/1323338531.17673.7.camel@twins
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:34:44 +01:00
Stephane Eranian
f1ac18af21 perf: Add support for PERF_HW_COUNT_REF_CPU_CYCLES
Add new generic hw event: ref-cycles, which maps to
PERF_HW_COUNT_REF_CPUCYCLES:

 $ perf stat -e ref-cycles ls

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323559734-3488-5-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:26:41 +01:00
Stephane Eranian
9c1497ea59 perf events: Add Intel x86 mapping for PERF_COUNT_HW_REF_CPU_CYCLES
Add event maps for Intel x86 processors (with architected PMU v2 or later).

On AMD, there is frequency scaling but no Turbo. There is no core
cycle event not subject to frequency scaling, therefore we do not
provide a mapping.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323559734-3488-4-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:26:39 +01:00
Stephane Eranian
c37e17497e perf events: Add PERF_COUNT_HW_REF_CPU_CYCLES generic PMU event
This event counts the number of reference core cpu cycles.
Reference means that the event increments at a constant rate which
is not subject to core CPU frequency adjustments. The event may
not count when the processor is in halted (low power) state.
As such, it may not be equivalent to wall clock time. However,
when the processor is not halted state, the event keeps
a constant correlation with wall clock time.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323559734-3488-3-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:26:37 +01:00
Stephane Eranian
cd09c0c40a perf events: Enable raw event support for Intel unhalted_reference_cycles event
This patch adds the encoding and definitions necessary for the
unhalted_reference_cycles event avaialble since Intel Core 2 processors.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323559734-3488-2-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:26:32 +01:00
Peter Zijlstra
f07fdec50a lockdep/waitqueues: Add better annotation
-> #2 (&tty->write_wait){-.-...}:

is a lot more informative than:

 -> #2 (key#19){-.....}:

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/n/tip-8zpopbny51023rdb0qq67eye@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:07:39 +01:00
Ingo Molnar
2d2b7749e8 Merge commit 'v3.2-rc6' into core/locking
Merge reason: Pick up the latest fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:06:37 +01:00
Francisco Jerez
b2e0d195d2 drm/nouveau: Fix notifier blocks over the 4GB mark.
Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
2011-12-21 19:01:47 +10:00
Francisco Jerez
4e03b4af6d drm/nouveau: Fix pushbufs over the 4GB mark.
Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Tested-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
2011-12-21 19:01:46 +10:00