linux-stable.git/include/linux/perf_event.h, branch v3.5.3

perf: Limit callchains to 127

2012-06-06T15:08:00+00:00

Stack depth of 255 seems excessive, given that copy_from_user_nmi()
could be slow.

Signed-off-by: Arun Sharma 
Cc: Linus Torvalds 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1334961696-19580-3-git-send-email-asharma@fb.com
Signed-off-by: Ingo Molnar

perf tools: Check if callchain is corrupted

2012-05-31T14:20:34+00:00

We faced segmentation fault on perf top -G at very high sampling rate
due to a corrupted callchain. While the root cause was not revealed (I
failed to figure it out), this patch tries to protect us from the
segfault on such cases.

Reported-by: Arnaldo Carvalho de Melo 
Signed-off-by: Namhyung Kim 
Cc: Namhyung Kim 
Cc: Paul Mackerras 
Cc: Peter Zijlstra 
Cc: Sunjin Yang 
Link: http://lkml.kernel.org/r/1338443007-24857-2-git-send-email-namhyung.kim@lge.com
Signed-off-by: Arnaldo Carvalho de Melo

Revert "sched, perf: Use a single callback into the scheduler"

2012-05-23T15:40:51+00:00

This reverts commit cb04ff9ac424 ("sched, perf: Use a single
callback into the scheduler").

Before this change was introduced, the process switch worked
like this (wrt. to perf event schedule):

     schedule (prev, next)
       - schedule out all perf events for prev
       - switch to next
       - schedule in all perf events for current (next)

After the commit, the process switch looks like:

     schedule (prev, next)
       - schedule out all perf events for prev
       - schedule in all perf events for (next)
       - switch to next

The problem is, that after we schedule perf events in, the pmu
is enabled and we can receive events even before we make the
switch to next - so "current" still being prev process (event
SAMPLE data are filled based on the value of the "current"
process).

Thats exactly what we see for test__PERF_RECORD test. We receive
SAMPLES with PID of the process that our tracee is scheduled
from.

Discussed with Peter Zijlstra:

 > Bah!, yeah I guess reverting is the right thing for now. Sad
 > though.
 >
 > So by having the two hooks we have a black-spot between them
 > where we receive no events at all, this black-spot covers the
 > hand-over of current and we thus don't receive the 'wrong'
 > events.
 >
 > I rather liked we could do away with both that black-spot and
 > clean up the code a little, but apparently people rely on it.

Signed-off-by: Jiri Olsa 
Acked-by: Peter Zijlstra 
Cc: acme@redhat.com
Cc: paulus@samba.org
Cc: cjashfor@linux.vnet.ibm.com
Cc: fweisbec@gmail.com
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/20120523111302.GC1638@m.brq.redhat.com
Signed-off-by: Ingo Molnar

sched, perf: Use a single callback into the scheduler

2012-05-09T13:23:17+00:00

We can easily use a single callback for both sched-in and sched-out. This
reduces the code footprint in the scheduler path as well as removes
the PMU black spot otherwise present between the out and in callback.

Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/n/tip-o56ajxp1edwqg6x9d31wb805@git.kernel.org
Signed-off-by: Ingo Molnar

perf: Pass last sampling period to perf_sample_data_init()

2012-05-09T13:23:12+00:00

We always need to pass the last sample period to
perf_sample_data_init(), otherwise the event distribution will be
wrong. Thus, modifiyng the function interface with the required period
as argument. So basically a pattern like this:

        perf_sample_data_init(&data, ~0ULL);
        data.period = event->hw.last_period;

will now be like that:

        perf_sample_data_init(&data, ~0ULL, event->hw.last_period);

Avoids unininitialized data.period and simplifies code.

Signed-off-by: Robert Richter 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1333390758-10893-3-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar

perf: Move mmap page data_head offset assertion out of header

2012-03-24T07:46:59+00:00

Having the build time assertion in header is making the perf
build fail on x86 with:

  ../../include/linux/perf_event.h:411:32: error: variably modified \
		‘__assert_mmap_data_head_offset’ at file scope [-Werror]

I'm moving the build time validation out of the header, because
I think it's better than to lessen the perf build warn/error
check.

Signed-off-by: Jiri Olsa 
Cc: acme@redhat.com
Cc: a.p.zijlstra@chello.nl
Cc: paulus@samba.org
Cc: cjashfor@linux.vnet.ibm.com
Cc: fweisbec@gmail.com
Link: http://lkml.kernel.org/r/1332513680-7870-1-git-send-email-jolsa@redhat.com
Signed-off-by: Ingo Molnar

perf: Fix mmap_page capabilities and docs

2012-03-23T08:52:16+00:00

Complete the syscall-less self-profiling feature and address
all complaints, namely:

 - capabilities, so we can detect what is actually available at runtime

     Add a capabilities field to perf_event_mmap_page to indicate
     what is actually available for use.

 - on x86: RDPMC weirdness due to being 40/48 bits and not sign-extending
   properly.

 - ABI documentation as to how all this stuff works.

Also improve the documentation for the new features.

Signed-off-by: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Vince Weaver 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Link: http://lkml.kernel.org/r/1332433596.2487.33.camel@twins
Signed-off-by: Ingo Molnar

perf: Adding sysfs group format attribute for pmu device

2012-03-16T17:06:06+00:00

Adding sysfs group 'format' attribute for pmu device that
contains a syntax description on how to construct raw events.

The event configuration is described in following
struct pefr_event_attr attributes:

  config
  config1
  config2

Each sysfs attribute within the format attribute group,
describes mapping of name and bitfield definition within
one of above attributes.

eg:
  "/sys/.../format/event" contains "config:0-7"
  "/sys/.../format/umask" contains "config:8-15"
  "/sys/.../format/usr"   contains "config:16"

the attribute value syntax is:

  line:      config ':' bits
  config:    'config' | 'config1' | 'config2"
  bits:      bits ',' bit_term | bit_term
  bit_term:  VALUE '-' VALUE | VALUE

Adding format attribute definitions for x86 cpu pmus.

Acked-by: Peter Zijlstra 
Signed-off-by: Peter Zijlstra 
Signed-off-by: Jiri Olsa 
Link: http://lkml.kernel.org/n/tip-vhdk5y2hyype9j63prymty36@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf: Add ABI reference sizes

2012-03-09T07:26:05+00:00

This patch adds reference sizes for revision 1
and 2 of the perf_event ABI, i.e., the size of
the perf_event_attr struct.

With Rev1: config2 was added = +8 bytes
With Rev2: branch_sample_type was added = +8 bytes

Adds the definition for Rev1, Rev2.

This is useful for tools trying to decode the revision
numbers based on the size of the struct.

Signed-off-by: Stephane Eranian 
Cc: peterz@infradead.org
Cc: acme@redhat.com
Cc: robert.richter@amd.com
Cc: ming.m.lin@intel.com
Cc: andi@firstfloor.org
Cc: asharma@fb.com
Cc: ravitillo@lbl.gov
Cc: vweaver1@eecs.utk.edu
Cc: khandual@linux.vnet.ibm.com
Cc: dsahern@gmail.com
Link: http://lkml.kernel.org/r/1328826068-11713-16-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar

perf: Add callback to flush branch_stack on context switch

2012-03-05T13:55:42+00:00

With branch stack sampling, it is possible to filter by priv levels.

In system-wide mode, that means it is possible to capture only user
level branches. The builtin SW LBR filter needs to disassemble code
based on LBR captured addresses. For that, it needs to know the task
the addresses are associated with. Because of context switches, the
content of the branch stack buffer may contain addresses from
different tasks.

We need a callback on context switch to either flush the branch stack
or save it. This patch adds a new callback in struct pmu which is called
during context switches. The callback is called only when necessary.
That is when a system-wide context has, at least, one event which
uses PERF_SAMPLE_BRANCH_STACK. The callback is never called for
per-thread context.

In this version, the Intel x86 code simply flushes (resets) the LBR
on context switches (fills it with zeroes). Those zeroed branches are
then filtered out by the SW filter.

Signed-off-by: Stephane Eranian 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1328826068-11713-11-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar