linux-stable.git/tools/perf/util/session.c, branch linux-4.1.y

perf session: Don't rely on evlist in pipe mode

2018-05-23T01:33:45+00:00

[ Upstream commit 0973ad97c187e06aece61f685b9c3b2d93290a73 ]

Session sets a number parameters that rely on evlist. These parameters
are not used in pipe-mode and should not be set, since evlist is
unavailable. Fix that.

Signed-off-by: David Carrillo-Cisneros 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: He Kuang 
Cc: Masami Hiramatsu 
Cc: Paul Turner 
Cc: Peter Zijlstra 
Cc: Simon Que 
Cc: Stephane Eranian 
Cc: Wang Nan 
Link: http://lkml.kernel.org/r/20170410201432.24807-6-davidcc@google.com
[ Check if file != NULL in perf_session__new(), like when used by builtin-top.c ]
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf inject: Copy events when reordering events in pipe mode

2018-05-23T01:33:45+00:00

[ Upstream commit 1e0d4f0200e4dbdfc38d818f329d8a0955f7c6f5 ]

__perf_session__process_pipe_events reuses the same memory buffer to
process all events in the pipe.

When reordering is needed (e.g. -b option), events are not immediately
flushed, but kept around until reordering is possible, causing
memory corruption.

The problem is usually observed by a "Unknown sample error" output. It
can easily be reproduced by:

  perf record -o - noploop | perf inject -b > output

Committer testing:

Before:

  $ perf record -o - stress -t 2 -c 2 | perf inject -b > /dev/null
  stress: info: [8297] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
  stress: info: [8297] successful run completed in 2s
  [ perf record: Woken up 3 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  Warning:
  Found 1 unknown events!

  Is this an older tool processing a perf.data file generated by a more recent tool?

  If that is not the case, consider reporting to linux-kernel@vger.kernel.org.

  $

After:

  $ perf record -o - stress -t 2 -c 2 | perf inject -b > /dev/null
  stress: info: [9027] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
  stress: info: [9027] successful run completed in 2s
  [ perf record: Woken up 3 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  no symbols found in /usr/bin/stress, maybe install a debug package?
  no symbols found in /usr/bin/stress, maybe install a debug package?
  $

Signed-off-by: David Carrillo-Cisneros 
Tested-by: Arnaldo Carvalho de Melo 
Acked-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: He Kuang 
Cc: Masami Hiramatsu 
Cc: Paul Turner 
Cc: Peter Zijlstra 
Cc: Simon Que 
Cc: Stephane Eranian 
Cc: Wang Nan 
Link: http://lkml.kernel.org/r/20170410201432.24807-3-davidcc@google.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf kvm record/report: 'unprocessable sample' error while recording/reporting guest data

2016-02-03T21:23:16+00:00

[ Upstream commit 3caeaa562733c4836e61086ec07666635006a787 ]

While recording guest samples in host using perf kvm record, it will
populate unprocessable sample error, though samples will be recorded
properly. While generating report using perf kvm report, no samples will
be processed and same error will populate. We have seen this behaviour
with upstream perf(4.4-rc3) on x86 and ppc64 hardware.

Reason behind this failure is, when it tries to fetch machine from
rb_tree of machines, it fails. As a part of tracing a bug, we figured
out that this code was incorrectly refactored in commit 54245fdc3576
("perf session: Remove wrappers to machines__find").

This patch will change the functionality such that if it can't fetch
machine in first trial, it will create one node of machine and add that to
rb_tree. So next time when it tries to fetch same machine from rb_tree,
it won't fail. Actually it was the case before refactoring of code in
aforementioned commit.

This patch is generated from acme perf/core branch.

Below I've mention an example that demonstrate the behaviour before and
after applying patch.

Before applying patch:
[Note: One needs to run guest before recording data in host]

  ravi@ravi-bangoria:~$ ./perf kvm record -a
  Warning:
  5903 unprocessable samples recorded.
  Do you have a KVM guest running and not using 'perf kvm'?
  [ perf record: Captured and wrote 1.409 MB perf.data.guest (285 samples) ]

  ravi@ravi-bangoria:~$ ./perf kvm report --stdio
  Warning:
  5903 unprocessable samples recorded.
  Do you have a KVM guest running and not using 'perf kvm'?
  # To display the perf.data header info, please use --header/--header-only options.
  #
  # Total Lost Samples: 0
  #
  # Samples: 285  of event 'cycles'
  # Event count (approx.): 88715406
  #
  # Overhead  Command  Shared Object  Symbol
  # ........  .......  .............  ......
  #

  # (For a higher level overview, try: perf report --sort comm,dso)
  #

After applying patch:

  ravi@ravi-bangoria:~$ ./perf kvm record -a
  [ perf record: Captured and wrote 1.188 MB perf.data.guest (17 samples) ]

  ravi@ravi-bangoria:~$ ./perf kvm report --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  #
  # Total Lost Samples: 0
  #
  # Samples: 17  of event 'cycles'
  # Event count (approx.): 700746
  #
  # Overhead  Command  Shared Object     Symbol
  # ........  .......  ................  ......................
  #
      34.19%  :5758    [unknown]         [g] 0xffffffff818682ab
      22.79%  :5758    [unknown]         [g] 0xffffffff812dc7f8
      22.79%  :5758    [unknown]         [g] 0xffffffff818650d0
      14.83%  :5758    [unknown]         [g] 0xffffffff8161a1b6
       2.49%  :5758    [unknown]         [g] 0xffffffff818692bf
       0.48%  :5758    [unknown]         [g] 0xffffffff81869253
       0.05%  :5758    [unknown]         [g] 0xffffffff81869250

Signed-off-by: Ravi Bangoria 
Cc: Naveen N. Rao 
Cc: stable@vger.kernel.org # v3.19+
Fixes: 54245fdc3576 ("perf session: Remove wrappers to machines__find")
Link: http://lkml.kernel.org/r/1449471302-11283-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf kmaps: Check kmaps to make code more robust

2015-04-08T12:07:03+00:00

This patch add checks in places where map__kmap is used to get kmaps
from struct kmap.

Error messages are added at map__kmap to warn invalid accessing of kmap
(for the case of !map->dso->kernel, kmap(map) does not exists at all).

Also, introduces map__kmaps() to warn uninitialized kmaps.

Reviewed-by: Ingo Molnar 
Signed-off-by: Wang Nan 
Cc: pi3orama@163.com
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Zefan Li 
Link: http://lkml.kernel.org/r/1428394966-131044-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo

perf ordered_samples: Remove references to perf_{evlist,tool} and machines

2015-03-31T20:52:32+00:00

As these can be obtained from the ordered_events pointer, via
container_of, reducing the cross section of ordered_samples.

These were added to ordered_samples in:

 commit b7b61cbebd789a3dbca522e3fdb727fe5c95593f
 Author: Arnaldo Carvalho de Melo 
 Date:   Tue Mar 3 11:58:45 2015 -0300

    perf ordered_events: Shorten function signatures

    By keeping pointers to machines, evlist and tool in ordered_events.

But that was more a transitional patch while moving stuff out from
perf_session.c to ordered_events.c and possibly not even needed by then,
as we could use the container_of() method and instead of having the
nr_unordered_samples stats in events_stats, we can have it in
ordered_samples.

Based-on-a-patch-by: Jiri Olsa 
Acked-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Borislav Petkov 
Cc: David Ahern 
Cc: Don Zickus 
Cc: Frederic Weisbecker 
Cc: Namhyung Kim 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/n/tip-4lk0t9js82g0tfc0x1onpkjt@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf session: Always initialize ordered_events

2015-03-31T20:52:31+00:00

Even when it is not used to actually reorder events, some of its fields
are used, like session->ordered_events->tool, to shorten function
signatures where tool, for instance, was being passed, as the tool is
needed for the ordered_events code, we need it there and might as well
use it for other perf_session needs.

This fixes a problem where 'perf script' had some condition that made
session->ordered_events not to be initialized even with its
script->tool ordered_events related flags asking for it to be, which
looks like another bug and needs to be investigated further.

Always initializing session->ordered_events at least leaves the current
assumptions in place, so do it now.

Reported-by: David Ahern 
Reviewed-by: David Ahern 
Tested-by: David Ahern 
Cc: Adrian Hunter 
Cc: Borislav Petkov 
Cc: Don Zickus 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/n/tip-b1xxk0rwkz2a0gip1uufmjqg@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf ordered_events: Adopt queue() method

2015-03-12T15:39:51+00:00

From perf_session, will be used in 'trace'.

Cc: Adrian Hunter 
Cc: Borislav Petkov 
Cc: David Ahern 
Cc: Don Zickus 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/n/tip-mfihndzaumx44h6y37ng2irb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: tool->finished_round() doesn't need perf_session

2015-03-12T15:39:49+00:00

It is all about flushing the ordered queue or piping it thru, no need
for a perf_session pointer.

Cc: Adrian Hunter 
Cc: Borislav Petkov 
Cc: David Ahern 
Cc: Don Zickus 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/n/tip-g47fx3ys0t9271cp0dcabjc7@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf ordered_events: Allow tools to specify a deliver method

2015-03-12T15:39:46+00:00

So that we can simplify the deliver method to pass just:

 (ordered_events, ordered_event, sample);

Cc: Adrian Hunter 
Cc: Borislav Petkov 
Cc: David Ahern 
Cc: Don Zickus 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/n/tip-j0s4bpxs5qza5tnkvjwom9rw@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf ordered_events: Shorten function signatures

2015-03-11T13:17:09+00:00

By keeping pointers to machines, evlist and tool in ordered_events.

Cc: Adrian Hunter 
Cc: Borislav Petkov 
Cc: David Ahern 
Cc: Don Zickus 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Stephane Eranian 
Link: http://lkml.kernel.org/n/tip-0c6huyaf59mqtm2ek9pmposl@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo