When creating a new filter, instead of allocating the filter to the
event call first and then processing the filter, it is easier to
process a temporary filter and then just swap it with the call filter.
By doing this, it simplifies the code.
A filter is allocated and processed, when it is done, it is
swapped with the call filter, synchronize_sched() is called to make
sure all callers are done with the old filter (filters are called
with premption disabled), and then the old filter is freed.
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Now that the filter logic does not require to save the pred results
on the stack, we can increase the max number of preds we allow.
As the preds are index by a short value, and we use the MSBs as flags
we can increase the max preds to 2^14 (16384) which should be way
more than enough.
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The MAX_FILTER_PRED is only needed by the kernel/trace/*.c files.
Move it to kernel/trace/trace.h.
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
There are many cases that a filter will contain multiple ORs or
ANDs together near the leafs. Walking up and down the tree to get
to the next compare can be a waste.
If there are several ORs or ANDs together, fold them into a single
pred and allocate an array of the conditions that they check.
This will speed up the filter by linearly walking an array
and can still break out if a short circuit condition is met.
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Since the filter walks a tree to determine if a match is made or not,
if the tree was incorrectly created, it could cause an infinite loop.
Add a check to walk the entire tree before assigning it as a filter
to make sure the tree is correct.
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The test if we should break out early for OR and AND operations
can be optimized by comparing the current result with
(pred->op == OP_OR)
That is if the result is true and the op is an OP_OR, or
if the result is false and the op is not an OP_OR (thus an OP_AND)
we can break out early in either case. Otherwise we continue
processing.
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently the filter_match_preds() requires a stack to push
and pop the preds to determine if the filter matches the record or not.
This has two drawbacks:
1) It requires a stack to store state information. As this is done
in fast paths we can't allocate the storage for this stack, and
we can't use a global as it must be re-entrant. The stack is stored
on the kernel stack and this greatly limits how many preds we
may allow.
2) All conditions are calculated even when a short circuit exists.
a || b will always calculate a and b even though a was determined
to be true.
Using a tree we can walk a constant structure that will save
the state as we go. The algorithm is simply:
pred = root;
do {
switch (move) {
case MOVE_DOWN:
if (OR or AND) {
pred = left;
continue;
}
if (pred == root)
break;
match = pred->fn();
pred = pred->parent;
move = left child ? MOVE_UP_FROM_LEFT : MOVE_UP_FROM_RIGHT;
continue;
case MOVE_UP_FROM_LEFT:
/* Only OR or AND can be a parent */
if (match && OR || !match && AND) {
/* short circuit */
if (pred == root)
break;
pred = pred->parent;
move = left child ?
MOVE_UP_FROM_LEFT :
MOVE_UP_FROM_RIGHT;
continue;
}
pred = pred->right;
move = MOVE_DOWN;
continue;
case MOVE_UP_FROM_RIGHT:
if (pred == root)
break;
pred = pred->parent;
move = left child ? MOVE_UP_FROM_LEFT : MOVE_UP_FROM_RIGHT;
continue;
}
done = 1;
} while (!done);
This way there's no strict limit to how many preds we allow
and it also will short circuit the logical operations when possible.
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Currently we allocate an array of pointers to filter_preds, and then
allocate a separate filter_pred for each item in the array.
This adds slight overhead in the filters as it needs to derefernce
twice to get to the op condition.
Allocating the preds themselves in a single array removes a dereference
as well as helps on the cache footprint.
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
By separating out the reseting of the filter->n_preds to zero from
the reallocation of preds for the filter, we can reset groups of
filters first, call synchronize_sched() just once, and then reallocate
each of the filters in the system group.
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
For every filter that is made, we create predicates to hold every
operation within the filter. We have a max of 32 predicates that we
can hold. Currently, we allocate all 32 even if we only need to
use one.
Part of the reason we do this is that the filter can be used at
any moment by any event. Fortunately, the filter is only used
with preemption disabled. By reseting the count of preds used "n_preds"
to zero, then performing a synchronize_sched(), we can safely
free and reallocate a new array of preds.
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The ops OR and AND act different from the other ops, as they
are the only ones to take other ops as their arguements.
These ops als change the logic of the filter_match_preds.
By removing the OR and AND fn's we can also remove the val1 and val2
that is passed to all other fn's and are unused.
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
The n_preds field of a file can change at anytime, and even can become
zero, just as the filter is about to be processed by an event.
In the case that is zero on entering the filter, return 1, telling
the caller the event matchs and should be trace.
Also use a variable and assign it with ACCESS_ONCE() such that the
count stays consistent within the function.
Cc: Tom Zanussi <tzanussi@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
lockdep, timer: Fix del_timer_sync() annotation
RTC: Prevents a division by zero in kernel code.
Calling local_bh_enable() will want to actually start processing
softirqs, which isn't a good idea since this can get called with IRQs
disabled.
Cure this by using _local_bh_enable() which doesn't start processing
softirqs, and use raw_local_irq_save() to avoid any softirqs from
happening without letting lockdep think IRQs are in fact disabled.
Reported-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Yong Zhang <yong.zhang0@gmail.com>
LKML-Reference: <20110203141548.039540914@chello.nl>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Fix update_curr_rt()
sched, docs: Update schedstats documentation to version 15
Currently the syscall_meta structures for the syscall tracepoints are
placed in the __syscall_metadata section, and at link time, the linker
makes one large array of all these syscall metadata structures. On boot
up, this array is read (much like the initcall sections) and the syscall
data is processed.
The problem is that there is no guarantee that gcc will place complex
structures nicely together in an array format. Two structures in the
same file may be placed awkwardly, because gcc has no clue that they
are suppose to be in an array.
A hack was used previous to force the alignment to 4, to pack the
structures together. But this caused alignment issues with other
architectures (sparc).
Instead of packing the structures into an array, the structures' addresses
are now put into the __syscall_metadata section. As pointers are always the
natural alignment, gcc should always pack them tightly together
(otherwise initcall, extable, etc would also fail).
By having the pointers to the structures in the section, we can still
iterate the trace_events without causing unnecessary alignment problems
with other architectures, or depending on the current behaviour of
gcc that will likely change in the future just to tick us kernel developers
off a little more.
The __syscall_metadata section is also moved into the .init.data section
as it is now only needed at boot up.
Suggested-by: David Miller <davem@davemloft.net>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Make the tracepoints more robust, making them solid enough to handle compiler
changes by not relying on anything based on compiler-specific behavior with
respect to structure alignment. Implement an approach proposed by David Miller:
use an array of const pointers to refer to the individual structures, and export
this pointer array through the linker script rather than the structures per se.
It will consume 32 extra bytes per tracepoint (24 for structure padding and 8
for the pointers), but are less likely to break due to compiler changes.
History:
commit 7e066fb8 tracepoints: add DECLARE_TRACE() and DEFINE_TRACE()
added the aligned(32) type and variable attribute to the tracepoint structures
to deal with gcc happily aligning statically defined structures on 32-byte
multiples.
One attempt was to use a 8-byte alignment for tracepoint structures by applying
both the variable and type attribute to tracepoint structures definitions and
declarations. It worked fine with gcc 4.5.1, but broke with gcc 4.4.4 and 4.4.5.
The reason is that the "aligned" attribute only specify the _minimum_ alignment
for a structure, leaving both the compiler and the linker free to align on
larger multiples. Because tracepoint.c expects the structures to be placed as an
array within each section, up-alignment cause NULL-pointer exceptions due to the
extra unexpected padding.
(this patch applies on top of -tip)
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: David S. Miller <davem@davemloft.net>
LKML-Reference: <20110126222622.GA10794@Krystal>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
cpu_stopper_thread()
migration_cpu_stop()
__migrate_task()
deactivate_task()
dequeue_task()
dequeue_task_rq()
update_curr_rt()
Will call update_curr_rt() on rq->curr, which at that time is
rq->stop. The problem is that rq->stop.prio matches an RT prio and
thus falsely assumes its a rt_sched_class task.
Reported-Debuged-Tested-Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Cc: stable@kernel.org # .37
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It is quite possible for the event to have been disabled between
perf_event_read() sending the IPI and the CPU servicing the IPI and
calling __perf_event_read(), hence revalidate the state.
Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Oleg reported that on architectures with
__ARCH_WANT_INTERRUPTS_ON_CTXSW the IPI from
task_oncpu_function_call() can land before perf_event_task_sched_in()
and cause interesting situations for eg. perf_install_in_context().
This patch reworks the task_oncpu_function_call() interface to give a
more usable primitive as well as rework all its users to hopefully be
more obvious as well as remove the races.
While looking at the code I also found a number of races against
perf_event_task_sched_out() which can flip contexts between tasks so
plug those too.
Reported-and-reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently the trace_event structures are placed in the _ftrace_events
section, and at link time, the linker makes one large array of all
the trace_event structures. On boot up, this array is read (much like
the initcall sections) and the events are processed.
The problem is that there is no guarantee that gcc will place complex
structures nicely together in an array format. Two structures in the
same file may be placed awkwardly, because gcc has no clue that they
are suppose to be in an array.
A hack was used previous to force the alignment to 4, to pack the
structures together. But this caused alignment issues with other
architectures (sparc).
Instead of packing the structures into an array, the structures' addresses
are now put into the _ftrace_event section. As pointers are always the
natural alignment, gcc should always pack them tightly together
(otherwise initcall, extable, etc would also fail).
By having the pointers to the structures in the section, we can still
iterate the trace_events without causing unnecessary alignment problems
with other architectures, or depending on the current behaviour of
gcc that will likely change in the future just to tick us kernel developers
off a little more.
The _ftrace_event section is also moved into the .init.data section
as it is now only needed at boot up.
Suggested-by: David Miller <davem@davemloft.net>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
move_native_irq() masks and unmasks the interrupt line
unconditionally, but the interrupt line might be masked due to a
threaded oneshot handler in progress. Unmasking the line in that case
can lead to interrupt storms. Observed on PREEMPT_RT.
Originally-from: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@kernel.org
If it was not possible to enable watchdog for any cpu, switch
watchdog_enabled back to 0, because it's visible via
kernel.watchdog sysctl.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: <stable@kernel.org>
LKML-Reference: <1296230433-6261-2-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Passing nowatchdog to kernel disables 2 things: creation of
watchdog threads AND initialization of percpu watchdog_hrtimer.
As hrtimers are initialized only at boot it's not possible to
enable watchdog later - for me all watchdog threads started to
eat 100% of CPU time, but they could just crash.
Additionally, even if these threads would start properly,
watchdog_disable_all_cpus was guarded by no_watchdog check, so
you couldn't disable watchdog.
To fix this, remove no_watchdog variable and use already
existing watchdog_enabled variable.
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
[ removed another no_watchdog instance ]
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: <stable@kernel.org>
LKML-Reference: <1296230433-6261-1-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since check_prlimit_permission always fails in the case of SUID/GUID
processes, such processes are not able to read or set their own limits.
This commit changes this by assuming that process can always read/change
its own limits.
Signed-off-by: Kacper Kornet <kornet@camk.edu.pl>
Acked-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 927c7a9e92 ("perf: Fix race in callchains") introduced
a mismatch in the sizing of struct callchain_cpus_entries.
nr_cpu_ids must be used instead of num_possible_cpus(), or we
might get out of bound memory accesses on some machines.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Miller <davem@davemloft.net>
Cc: Stephane Eranian <eranian@google.com>
CC: stable@kernel.org
LKML-Reference: <1295980851.3588.351.camel@edumazet-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The delta in clock_task is a more fair attribution of how much time a tg has
been contributing load to the current cpu.
While not really important it also means we're more in sync (by magnitude)
with respect to periodic updates (since __update_curr deltas are clock_task
based).
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044852.007092349@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Since updates are against an entity's queuing cfs_rq it's not possible to
enter update_cfs_{shares,load} with a NULL cfs_rq. (Indeed, update_cfs_load
would crash prior to the check if we did anyway since we load is examined
during the initializers).
Also, in the update_cfs_load case there's no point
in maintaining averages for rq->cfs_rq since we don't perform shares
distribution at that level -- NULL check is replaced accordingly.
Thanks to Dan Carpenter for pointing out the deference before NULL check.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044851.825284940@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
While care is taken around the zero-point in effective_load to not exceed
the instantaneous rq->weight, it's still possible (e.g. using wake_idx != 0)
for (load + effective_load) to underflow.
In this case the comparing the unsigned values can result in incorrect balanced
decisions.
Signed-off-by: Paul Turner <pjt@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110122044851.734245014@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: wacom - pass touch resolution to clients through input_absinfo
Input: wacom - add 2 Bamboo Pen and touch models
Input: sysrq - ensure sysrq_enabled and __sysrq_enabled are consistent
Input: sparse-keymap - fix KEY_VSW handling in sparse_keymap_setup
Input: tegra-kbc - add tegra keyboard driver
Input: gpio_keys - switch to using request_any_context_irq
Input: serio - allow registered drivers to get status flag
Input: ct82710c - return proper error code for ct82c710_open
Input: bu21013_ts - added regulator support
Input: bu21013_ts - remove duplicate resolution parameters
Input: tnetv107x-ts - don't treat NULL clk as an error
Input: tnetv107x-keypad - don't treat NULL clk as an error
Fix up trivial conflicts in drivers/input/keyboard/Makefile due to
additions of tc3589x/Tegra drivers
The -rt patches change the console_semaphore to console_mutex. As a
result, a quite large chunk of the patches changes all
acquire/release_console_sem() to acquire/release_console_mutex()
This commit makes things use more neutral function names which dont make
implications about the underlying lock.
The only real change is the return value of console_trylock which is
inverted from try_acquire_console_sem()
This patch also paves the way to switching console_sem from a semaphore to
a mutex.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: make console_trylock return 1 on success, per Geert]
Signed-off-by: Torben Hohn <torbenh@gmx.de>
Cc: Thomas Gleixner <tglx@tglx.de>
Cc: Greg KH <gregkh@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf tools: Fix time function double declaration with glibc
perf tools: Fix build by checking if extra warnings are supported
perf tools: Fix build when using gcc 3.4.6
perf tools: Add missing header, fixes build
perf tools: Fix 64 bit integer format strings
perf test: Fix build on older glibcs
perf: perf_event_exit_task_context: s/rcu_dereference/rcu_dereference_raw/
perf test: Use cpu_map->[cpu] when setting affinity
perf symbols: Fix annotation of thumb code
perf: Annotate cpuctx->ctx.mutex to avoid a lockdep splat
powerpc, perf: Fix frequency calculation for overflowing counters (FSL version)
perf: Fix perf_event_init_task()/perf_event_free_task() interaction
perf: Fix find_get_context() vs perf_event_exit_task() race
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched: Fix poor interactivity on UP systems due to group scheduler nice tune bug
Currently sysrq_enabled and __sysrq_enabled are initialised separately
and inconsistently, leading to sysrq being actually enabled by reported
as not enabled in sysfs. The first change to the sysfs configurable
synchronises these two:
static int __read_mostly sysrq_enabled = 1;
static int __sysrq_enabled;
Add a common define to carry the default for these preventing them becoming
out of sync again. Default this to 1 to mirror previous behaviour.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: stable@kernel.org
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Michael Witten and Christian Kujau reported that the autogroup
scheduling feature hurts interactivity on their UP systems.
It turns out that this is an older bug in the group scheduling code,
and the wider appeal provided by the autogroup feature exposed it
more prominently.
When on UP with FAIR_GROUP_SCHED enabled, tune shares
only affect tg->shares, but is not reflected in
tg->se->load. The reason is that update_cfs_shares()
does nothing on UP.
So introduce update_cfs_shares() for UP && FAIR_GROUP_SCHED.
This issue was found when enable autogroup scheduling was enabled,
but it is an older bug that also exists on cgroup.cpu on UP.
Reported-and-Tested-by: Michael Witten <mfwitten@gmail.com>
Reported-and-Tested-by: Christian Kujau <christian@nerdbynature.de>
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Acked-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Mike Galbraith <efault@gmx.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <20110124073352.GA24186@windriver.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently only drivers that are built as modules have their versions
shown in /sys/module/<module_name>/version, but this information might
also be useful for built-in drivers as well. This especially important
for drivers that do not define any parameters - such drivers, if
built-in, are completely invisible from userspace.
This patch changes MODULE_VERSION() macro so that in case when we are
compiling built-in module, version information is stored in a separate
section. Kernel then uses this data to create 'version' sysfs attribute
in the same fashion it creates attributes for module parameters.
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* 'fixes-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: note the nested NOT_RUNNING test in worker_clr_flags() isn't a noop
workqueue: relax lockdep annotation on flush_work()
In theory, almost every user of task->child->perf_event_ctxp[]
is wrong. find_get_context() can install the new context at any
moment, we need read_barrier_depends().
dbe08d82ce "perf: Fix
find_get_context() vs perf_event_exit_task() race" added
rcu_dereference() into perf_event_exit_task_context() to make
the precedent, but this makes __rcu_dereference_check() unhappy.
Use rcu_dereference_raw() to shut up the warning.
Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: acme@redhat.com
Cc: paulus@samba.org
Cc: stern@rowland.harvard.edu
Cc: a.p.zijlstra@chello.nl
Cc: fweisbec@gmail.com
Cc: roland@redhat.com
Cc: prasad@linux.vnet.ibm.com
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
LKML-Reference: <20110121174547.GA8796@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Lockdep spotted:
loop_1b_instruc/1899 is trying to acquire lock:
(event_mutex){+.+.+.}, at: [<ffffffff810e1908>] perf_trace_init+0x3b/0x2f7
but task is already holding lock:
(&ctx->mutex){+.+.+.}, at: [<ffffffff810eb45b>] perf_event_init_context+0xc0/0x218
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&ctx->mutex){+.+.+.}:
-> #2 (cpu_hotplug.lock){+.+.+.}:
-> #1 (module_mutex){+.+...}:
-> #0 (event_mutex){+.+.+.}:
But because the deadlock would be cpuhotplug (cpu-event) vs fork
(task-event) it cannot, in fact, happen. We can annotate this by giving the
perf_event_context used for the cpuctx a different lock class from those
used by tasks.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
All architectures are finally converted. Remove the cruft.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Michal Simek <monstr@monstr.eu>
Acked-by: David Howells <dhowells@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jeff Dike <jdike@addtoit.com>
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
smp: Allow on_each_cpu() to be called while early_boot_irqs_disabled status to init/main.c
lockdep: Move early boot local IRQ enable/disable status to init/main.c
* akpm:
kernel/smp.c: consolidate writes in smp_call_function_interrupt()
kernel/smp.c: fix smp_call_function_many() SMP race
memcg: correctly order reading PCG_USED and pc->mem_cgroup
backlight: fix 88pm860x_bl macro collision
drivers/leds/ledtrig-gpio.c: make output match input, tighten input checking
MAINTAINERS: update Atmel AT91 entry
mm: fix truncate_setsize() comment
memcg: fix rmdir, force_empty with THP
memcg: fix LRU accounting with THP
memcg: fix USED bit handling at uncharge in THP
memcg: modify accounting function for supporting THP better
fs/direct-io.c: don't try to allocate more than BIO_MAX_PAGES in a bio
mm: compaction: prevent division-by-zero during user-requested compaction
mm/vmscan.c: remove duplicate include of compaction.h
memblock: fix memblock_is_region_memory()
thp: keep highpte mapped until it is no longer needed
kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT
