If counters are disabled globally when a perfcounter IRQ/NMI hits,
and if we throttle in that case, we'll promote the '0' value to
the next lapic IRQ and disable all perfcounters at that point,
permanently ...
Fix it.
[ Impact: fix hung perfcounters under load ]
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Take the counter width into account instead of assuming 32 bits.
In particular Nehalem has 44 bit wide counters, and all
arithmetics should happen on a 44-bit signed integer basis.
[ Impact: fix rare event imprecision, warning message on Nehalem ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Allow specifying a pid instead of always fork+exec'ing a command.
Because the PERF_EVENT_COMM and PERF_EVENT_MMAP events happened before
we connected, we must synthesize them so that 'perf report' can get what
it needs.
[ Impact: add new command line option ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
LKML-Reference: <20090515015046.GA13664@ghostprotocols.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
I noticed that when enabling a group via the PERF_COUNTER_IOC_ENABLE
ioctl on the group leader, the counters weren't enabled and counting
immediately on return from the ioctl, but did start counting a little
while later (presumably after a context switch).
The reason was that __perf_counter_enable calls group_sched_in which
calls hw_perf_group_sched_in, which on powerpc assumes that the caller
has called hw_perf_save_disable already. Until commit 46d686c6
("perf_counter: put whole group on when enabling group leader") it was
true that all callers of group_sched_in had called
hw_perf_save_disable first, and the powerpc hw_perf_group_sched_in
relies on that (there isn't an x86 version).
This fixes the problem by putting calls to hw_perf_save_disable /
hw_perf_restore around the calls to group_sched_in and
counter_sched_in in __perf_counter_enable. Having the calls to
hw_perf_save_disable/restore around the counter_sched_in call is
harmless and makes this call consistent with the other call sites
of counter_sched_in, which have all called hw_perf_save_disable first.
[ Impact: more precise counter group disable/enable functionality ]
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <18953.25733.53359.147452@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
A compile warning triggered because we are calling
atomic_set(&counter->count). But since counter->count
is an atomic64_t, we have to use atomic64_set.
So the count can be set short, resulting in the reset ioctl
only resetting the low word.
[ Impact: clear counter properly during the reset ioctl ]
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <18951.48285.270311.981806@drongo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The context-switch software counter gives inflated values at present
because each scheduler tick and each process-wide counter
enable/disable prctl gets counted as a context switch.
This happens because perf_counter_task_tick, perf_counter_task_disable
and perf_counter_task_enable all call perf_counter_task_sched_out,
which calls perf_swcounter_event to record a context switch event.
This fixes it by introducing a variant of perf_counter_task_sched_out
with two underscores in front for internal use within the perf_counter
code, and makes perf_counter_task_{tick,disable,enable} call it. This
variant doesn't record a context switch event, and takes a struct
perf_counter_context *. This adds the new variant rather than
changing the behaviour or interface of perf_counter_task_sched_out
because that is called from other code.
[ Impact: fix inflated context-switch event counts ]
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <18951.48034.485580.498953@drongo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Currently, if you have a group where the leader is disabled and there
are siblings that are enabled, and then you enable the leader, we only
put the leader on the PMU, and not its enabled siblings. This is
incorrect, since the enabled group members should be all on or all off
at any given point.
This fixes it by adding a call to group_sched_in in
__perf_counter_enable in the case where we're enabling a group leader.
To avoid the need for a forward declaration this also moves
group_sched_in up before __perf_counter_enable. The actual content of
group_sched_in is unchanged by this patch.
[ Impact: fix bug in counter enable code ]
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <18951.34946.451546.691693@drongo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
s/PERFMON/perfcounters for perfcounter interrupt throttling warning.
'perfmon' is the CPU feature name that is Intel-only, while we do
throttling in a generic way.
[ Impact: cleanup ]
Signed-off-by: Mike Galbraith <efault@gmx.de>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There is a buffer overwrite problem in builtin-top.c line 526, When I
tried to use ./perf top command, it was giving memory corruption
problem.
[ Impact: fix 'perf top' crash ]
LKML-Reference: <3fee128b0905092313x608e65e0l7b1116d86914114f@mail.gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Allow recording the CPU number the event was generated on.
RFC: this leaves a u32 as reserved, should we fill in the
node_id() there, or leave this open for future extention,
as userspace can already easily do the cpu->node mapping
if needed.
[ Impact: extend perfcounter output record format ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090508170029.008627711@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Much like CONFIG_RECORD_GROUP records the hw_event.config to
identify the values, allow to record this for all counters.
[ Impact: extend perfcounter output record format ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090508170028.923228280@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Corey noticed that ioctl()s on grouped counters didn't work on
the whole group. This extends the ioctl() interface to take a
second argument that is interpreted as a flags field. We then
provide PERF_IOC_FLAG_GROUP to toggle the behaviour.
Having this flag gives the greatest flexibility, allowing you
to individually enable/disable/reset counters in a group, or
all together.
[ Impact: fix group counter enable/disable semantics ]
Reported-by: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20090508170028.837558214@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
perf_counter_task_tick() does way too much work to find out
there's nothing to do. Provide an easy short-circuit for the
normal case where there are no counters on the system.
[ Impact: micro-optimization ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090508170028.750619201@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Merge reason: we moved a mutex.h commit that originated from the
perfcounters tree into core/locking - but now merge
back that branch to solve a merge artifact and to
pick up cleanups of this commit that happened in
core/locking.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Redirect the output to the parent counter and put in some sanity checks.
[ Impact: new perfcounter feature - inherited sampling counters ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090505155437.331556171@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Use -1 instead of 0 as unlocked, since 0 is a valid cpu number.
( This is not an issue right now but will be once we allow multiple
counters to output to the same mmap area. )
[ Impact: prepare code for multi-counter profile output ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090505155437.232686598@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Provide a threshold to relax the mlock accounting, increasing usability.
Each counter gets perf_counter_mlock_kb for free.
[ Impact: allow more mmap buffering ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090505155437.112113632@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Provide a way to reset an existing counter - this eases PAPI
libraries around perfcounters.
Similar to read() it doesn't collapse pending child counters.
[ Impact: new perfcounter fd ioctl method to reset counters ]
Suggested-by: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20090505155437.022272933@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Keep data_head up-to-date irrespective of notifications. This fixes
the case where you disable a counter and don't get a notification for
the last few pending events, and it also allows polling usage.
[ Impact: increase precision of perfcounter mmap-ed fields ]
Suggested-by: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20090505155436.925084300@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fixed-purpose counters stopped working in a simple 'perf stat ls' run:
<not counted> cache references
<not counted> cache misses
Due to:
ef7b3e0: perf_counter, x86: remove vendor check in fixed_mode_idx()
Which made x86_pmu.num_counters_fixed matter: if it's nonzero, the
fixed-purpose counters are utilized.
But on v2 perfmon this field is not set (despite there being
fixed-purpose PMCs). So add a quirk to set the number of fixed-purpose
counters to at least three.
[ Impact: add quirk for three fixed-purpose counters on certain Intel CPUs ]
Cc: Robert Richter <robert.richter@amd.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241002046-8832-28-git-send-email-robert.richter@amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Now percpu counters can be initialized very early. But the init
sequence uses mutex_lock(). Fortunately, perf_resource_mutex should
be a spinlock anyway, so convert it.
[ Impact: fix crash due to early init mutex use ]
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
percpu scheduling for perfcounters wants to take the context lock,
but that lock first needs to be initialized. Currently it is an
early_initcall() - but that is too late, the task tick runs much
sooner than that.
Call it explicitly from the scheduler init sequence instead.
[ Impact: fix access-before-init crash ]
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Invert the atomic_inc_not_zero() test so that we will indeed detect the
first activation.
Also rename the global num_counters, since its easy to confuse with
x86_pmu.num_counters.
[ Impact: fix non-working perfcounters on AMD CPUs, cleanup ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1241455664.7620.4938.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This used to be unstable when we had the rq->lock dependencies,
but now that they are that of the past we can turn on percpu
counter RR too.
[ Impact: handle counter over-commit for per-CPU counters too ]
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Update the documentation to reflect the current state of affairs
[ Impact: documentation update ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090501102533.296727903@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When we don't have any perf-counters active, don't act like we know
what the NMI is for.
[ Impact: fix hard hang with nmi_watchdog=2 ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090501102533.109867793@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When two (or more) contexts output to the same buffer, it is possible
to observe half written output.
Suppose we have CPU0 doing perf_counter_mmap(), CPU1 doing
perf_counter_overflow(). If CPU1 does a wakeup and exposes head to
user-space, then CPU2 can observe the data CPU0 is still writing.
[ Impact: fix occasionally corrupted profiling records ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090501102533.007821627@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This is necessary to avoid the conflict of syscall numbers.
Conflicts:
arch/x86/ia32/ia32entry.S
arch/x86/include/asm/unistd_32.h
arch/x86/include/asm/unistd_64.h
Fixes up the borked syscall numbers of perfcounters versus
preadv/pwritev as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
sys_kill has the per thread counterpart sys_tgkill. sigqueueinfo is
missing a thread directed counterpart. Such an interface is important
for migrating applications from other OSes which have the per thread
delivery implemented.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: Ulrich Drepper <drepper@redhat.com>
Split out the code from do_tkill to make it reusable by the follow up
patch which implements sys_rt_tgsigqueueinfo
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Bail out early if a record has zero size - we have no chance to make
reliable progress in that case. Print out the offset where this happens,
and print the number of bytes we missed out on.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
include/linux/mutex.h:136: warning: 'mutex_lock' declared inline after being called
include/linux/mutex.h:136: warning: previous declaration of 'mutex_lock' was here
uninline it.
[ Impact: clean up and uninline, address compiler warning ]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Eric Paris <eparis@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <200904292318.n3TNIsi6028340@imap1.linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This adds my name to the list of copyright holders on the core
perf_counter.c, since I have contributed a significant amount of the
code in there.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Robert Richter <robert.richter@amd.com>
LKML-Reference: <18936.59200.888049.746658@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ecryptfs/ecryptfs-2.6:
eCryptfs: Fix min function comparison warning
ecryptfs: fix printk format warning
