<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/tools/perf/util/record.h, branch linux-5.14.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.</subtitle>
<id>https://universe.0xinfinity.dev/distro/kernel/atom?h=linux-5.14.y</id>
<link rel='self' href='https://universe.0xinfinity.dev/distro/kernel/atom?h=linux-5.14.y'/>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/'/>
<updated>2021-01-20T17:34:20Z</updated>
<entry>
<title>perf record: Add support for PERF_SAMPLE_CODE_PAGE_SIZE</title>
<updated>2021-01-20T17:34:20Z</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@linux.intel.com</email>
</author>
<published>2021-01-05T19:57:49Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=c1de7f3d84ca324c7cda85c3ce27b11741af2124'/>
<id>urn:sha1:c1de7f3d84ca324c7cda85c3ce27b11741af2124</id>
<content type='text'>
Adds the infrastructure to sample the code address page size.

Introduce a new --code-page-size option for perf record.

Signed-off-by: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Originally-by: Stephane Eranian &lt;eranian@google.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Link: https://lore.kernel.org/r/20210105195752.43489-4-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Add --buildid-mmap option to enable PERF_RECORD_MMAP2's build id</title>
<updated>2020-12-28T14:35:57Z</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2020-12-14T10:54:57Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=e29386c8f7d71fa59a6524b174a9c75ff74be580'/>
<id>urn:sha1:e29386c8f7d71fa59a6524b174a9c75ff74be580</id>
<content type='text'>
Add --buildid-mmap option to enable build id in PERF_RECORD_MMAP2 events.

It will only work if there's kernel support for that and it disables
build id cache (implies --no-buildid).

It's also possible to enable it permanently via config option in
~/.perfconfig file:

  [record]
  build-id=mmap

Also added build_id bit in the verbose output for perf_event_attr:

  # perf record --buildid-mmap -vv
  ...
  perf_event_attr:
    type                             1
    size                             120
    ...
    build_id                         1

Adding also missing text_poke bit.

Committer testing:

  $ perf record -h build

   Usage: perf record [&lt;options&gt;] [&lt;command&gt;]
      or: perf record [&lt;options&gt;] -- &lt;command&gt; [&lt;options&gt;]

      -B, --no-buildid      do not collect buildids in perf.data
      -N, --no-buildid-cache
                            do not update the buildid cache
          --buildid-all     Record build-id of all DSOs regardless of hits
          --buildid-mmap    Record build-id in map events

  $

  $ perf record --buildid-mmap sleep 1
  Failed: no support to record build id in mmap events, update your kernel.
  $

After adding the needed kernel bits in a test kernel:

  $ perf record -vv --buildid-mmap sleep 1 |&amp; grep -m1 build
  Enabling build id in mmap2 events.
  $ perf evlist -v
  cycles:u: size: 120, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD, read_format: ID, disabled: 1, inherit: 1, exclude_kernel: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1, build_id: 1
  $

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Acked-by: Ian Rogers &lt;irogers@google.com&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Alexei Budankov &lt;abudankov@huawei.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Michael Petlan &lt;mpetlan@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lore.kernel.org/lkml/20201214105457.543111-16-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Support new sample type for data page size</title>
<updated>2020-12-17T17:36:16Z</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@linux.intel.com</email>
</author>
<published>2020-11-30T17:27:53Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=542b88fd12769bf5be307b11ca0f94a6140bba82'/>
<id>urn:sha1:542b88fd12769bf5be307b11ca0f94a6140bba82</id>
<content type='text'>
Support new sample type PERF_SAMPLE_DATA_PAGE_SIZE for page size.

Add new option --data-page-size to record sample data page size.

Signed-off-by: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Link: http://lore.kernel.org/lkml/20201130172803.2676-3-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf tools: Add FIFO file names as alternative options to --control</title>
<updated>2020-09-04T17:38:15Z</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2020-09-02T10:57:07Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=a8fcbd269b4340c36dbf99b4453bcbfe128d93fb'/>
<id>urn:sha1:a8fcbd269b4340c36dbf99b4453bcbfe128d93fb</id>
<content type='text'>
Enable the --control option to accept file names as an alternative to
file descriptors.

Example:

  $ mkfifo perf.control
  $ mkfifo perf.ack
  $ cat perf.ack &amp;
  [1] 6808
  $ perf record --control fifo:perf.control,perf.ack -- sleep 300 &amp;
  [2] 6810
  $ echo disable &gt; perf.control
  $ Events disabled
  ack

  $ echo enable &gt; perf.control
  $ Events enabled
  ack

  $ echo disable &gt; perf.control
  $ Events disabled
  ack

  $ kill %2
  [ perf record: Woken up 4 times to write data ]
  $ [ perf record: Captured and wrote 0.018 MB perf.data (7 samples) ]

  [1]-  Done                    cat perf.ack
  [2]+  Terminated              perf record --control fifo:perf.control,perf.ack -- sleep 300
  $

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Acked-by: Alexey Budankov &lt;alexey.budankov@linux.intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: http://lore.kernel.org/lkml/20200902105707.11491-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Introduce --control fd:ctl-fd[,ack-fd] options</title>
<updated>2020-08-04T11:50:52Z</updated>
<author>
<name>Alexey Budankov</name>
<email>alexey.budankov@linux.intel.com</email>
</author>
<published>2020-07-17T07:08:23Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=1d078ccb33807546c73e07a79fca6a976b7ecac8'/>
<id>urn:sha1:1d078ccb33807546c73e07a79fca6a976b7ecac8</id>
<content type='text'>
Introduce --control fd:ctl-fd[,ack-fd] options to pass open file
descriptors numbers from command line.

Extend perf-record.txt file with --control fd:ctl-fd[,ack-fd] options
description.

Document possible usage model introduced by --control fd:ctl-fd[,ack-fd]
options by providing example bash shell script.

Signed-off-by: Alexey Budankov &lt;alexey.budankov@linux.intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lore.kernel.org/lkml/8dc01e1a-3a80-3f67-5385-4bc7112b0dd3@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Extend -D,--delay option with -1 value</title>
<updated>2020-08-04T11:50:04Z</updated>
<author>
<name>Alexey Budankov</name>
<email>alexey.budankov@linux.intel.com</email>
</author>
<published>2020-07-17T07:07:03Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=68cd3b45b93d07f7e7d853f330d3a37b560b04f2'/>
<id>urn:sha1:68cd3b45b93d07f7e7d853f330d3a37b560b04f2</id>
<content type='text'>
Extend -D,--delay option with -1 to start collection with events
disabled to be enabled later by 'enable' command provided via control
file descriptor.

Signed-off-by: Alexey Budankov &lt;alexey.budankov@linux.intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Acked-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lore.kernel.org/lkml/3e7d362c-7973-ee5d-e81e-c60ea22432c3@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf tools: Add support for PERF_RECORD_TEXT_POKE</title>
<updated>2020-07-10T11:20:01Z</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2020-05-12T12:19:18Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=246eba8e9041c4774738645c72b6efac7601db22'/>
<id>urn:sha1:246eba8e9041c4774738645c72b6efac7601db22</id>
<content type='text'>
Add processing for PERF_RECORD_TEXT_POKE events. When a text poke event
is processed, then the kernel dso data cache is updated with the poked
bytes.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Leo Yan &lt;leo.yan@linaro.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Cc: x86@kernel.org
Link: http://lore.kernel.org/lkml/20200512121922.8997-12-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Respect --no-switch-events</title>
<updated>2020-05-28T14:33:36Z</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2020-05-28T12:08:58Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=16b4b4e1a0038365a6734a4f50aba77e57865c8e'/>
<id>urn:sha1:16b4b4e1a0038365a6734a4f50aba77e57865c8e</id>
<content type='text'>
Context switch events are added automatically by Intel PT and Coresight.

Make it possible to suppress them. That is useful for tracing the
scheduler without the disturbance that the switch event processing
creates.

Example:

  Prerequisites:

    $ which perf
    ~/bin/perf
    $ sudo setcap "cap_sys_rawio,cap_sys_admin,cap_sys_ptrace,cap_syslog,cap_ipc_lock=ep" ~/bin/perf
    $ sudo chmod +r /proc/kcore

  Before:

    $ perf record --no-switch-events --kcore -a -e intel_pt//k -- sleep 0.001
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.938 MB perf.data ]
    $ perf script -D | grep PERF_RECORD_SWITCH | wc -l
    572

  After:

    $ perf record --no-switch-events --kcore -a -e intel_pt//k -- sleep 0.001
    Warning:
    Intel Processor Trace decoding will not be possible except for kernel tracing!
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.838 MB perf.data ]
    $ perf script -D | grep PERF_RECORD_SWITCH | wc -l
    0

    $ sudo chmod go-r /proc/kcore
    $ sudo setcap -r ~/bin/perf

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Mathieu Poirier &lt;mathieu.poirier@linaro.org&gt;
Link: http://lore.kernel.org/lkml/20200528120859.21604-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Add num-synthesize-threads option</title>
<updated>2020-04-23T14:10:41Z</updated>
<author>
<name>Stephane Eranian</name>
<email>eranian@google.com</email>
</author>
<published>2020-04-22T15:50:38Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=d99c22eabee45f40ca44b877a1adde028f14b6b4'/>
<id>urn:sha1:d99c22eabee45f40ca44b877a1adde028f14b6b4</id>
<content type='text'>
To control degree of parallelism of the synthesize_mmap() code which
is scanning /proc/PID/task/PID/maps and can be time consuming.
Mimic perf top way of handling the option.
If not specified will default to 1 thread, i.e. default behavior before
this option.

On a desktop computer the processing of /proc/PID/task/PID/maps isn't
slow enough to warrant parallel processing and the thread creation has
some cost - hence the default of 1. On a loaded server with
&gt;100 cores it is possible to see synthesis times in the order of
seconds and in this case having the option is desirable.

As the processing is a synchronization point, it is legitimate to worry if
Amdahl's law will apply to this patch. Profiling with this patch in
place:
https://lore.kernel.org/lkml/20200415054050.31645-4-irogers@google.com/
shows:
...
      - 32.59% __perf_event__synthesize_threads
         - 32.54% __event__synthesize_thread
            + 22.13% perf_event__synthesize_mmap_events
            + 6.68% perf_event__get_comm_ids.constprop.0
            + 1.49% process_synthesized_event
            + 1.29% __GI___readdir64
            + 0.60% __opendir
...
That is the processing is 1.49% of execution time and there is plenty to
make parallel. This is shown in the benchmark in this patch:

https://lore.kernel.org/lkml/20200415054050.31645-2-irogers@google.com/

  Computing performance of multi threaded perf event synthesis by
  synthesizing events on CPU 0:
   Number of synthesis threads: 1
     Average synthesis took: 127729.000 usec (+- 3372.880 usec)
     Average num. events: 21548.600 (+- 0.306)
     Average time per event 5.927 usec
   Number of synthesis threads: 2
     Average synthesis took: 88863.500 usec (+- 385.168 usec)
     Average num. events: 21552.800 (+- 0.327)
     Average time per event 4.123 usec
   Number of synthesis threads: 3
     Average synthesis took: 83257.400 usec (+- 348.617 usec)
     Average num. events: 21553.200 (+- 0.327)
     Average time per event 3.863 usec
   Number of synthesis threads: 4
     Average synthesis took: 75093.000 usec (+- 422.978 usec)
     Average num. events: 21554.200 (+- 0.200)
     Average time per event 3.484 usec
   Number of synthesis threads: 5
     Average synthesis took: 64896.600 usec (+- 353.348 usec)
     Average num. events: 21558.000 (+- 0.000)
     Average time per event 3.010 usec
   Number of synthesis threads: 6
     Average synthesis took: 59210.200 usec (+- 342.890 usec)
     Average num. events: 21560.000 (+- 0.000)
     Average time per event 2.746 usec
   Number of synthesis threads: 7
     Average synthesis took: 54093.900 usec (+- 306.247 usec)
     Average num. events: 21562.000 (+- 0.000)
     Average time per event 2.509 usec
   Number of synthesis threads: 8
     Average synthesis took: 48938.700 usec (+- 341.732 usec)
     Average num. events: 21564.000 (+- 0.000)
     Average time per event 2.269 usec

Where average time per synthesized event goes from 5.927 usec with 1
thread to 2.269 usec with 8. This isn't a linear speed up as not all of
synthesize code has been made parallel. If the synthesis time was about
10 seconds then using 8 threads may bring this down to less than 4.

Signed-off-by: Stephane Eranian &lt;eranian@google.com&gt;
Reviewed-by: Ian Rogers &lt;irogers@google.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Alexey Budankov &lt;alexey.budankov@linux.intel.com&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Tony Jones &lt;tonyj@suse.de&gt;
Cc: yuzhoujian &lt;yuzhoujian@didichuxing.com&gt;
Link: http://lore.kernel.org/lkml/20200422155038.9380-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Add --all-cgroups option</title>
<updated>2020-04-03T12:37:55Z</updated>
<author>
<name>Namhyung Kim</name>
<email>namhyung@kernel.org</email>
</author>
<published>2020-03-25T12:45:34Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=8fb4b67939e169fca68174e9ac7be79fe9a04498'/>
<id>urn:sha1:8fb4b67939e169fca68174e9ac7be79fe9a04498</id>
<content type='text'>
The --all-cgroups option is to enable cgroup profiling support.  It
tells kernel to record CGROUP events in the ring buffer so that perf
report can identify task/cgroup association later.

  [root@seventh ~]# perf record --all-cgroups --namespaces /wb/cgtest
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.042 MB perf.data (558 samples) ]
  [root@seventh ~]# perf report --stdio -s cgroup_id,cgroup,pid
  # To display the perf.data header info, please use --header/--header-only options.
  #
  #
  # Total Lost Samples: 0
  #
  # Samples: 558  of event 'cycles'
  # Event count (approx.): 458017341
  #
  # Overhead  cgroup id (dev/inode)  Cgroup          Pid:Command
  # ........  .....................  ..........  ...............
  #
      33.15%  4/0xeffffffb           /sub           9615:looper0
      32.83%  4/0xf00002f5           /sub/cgrp2     9620:looper2
      32.79%  4/0xf00002f4           /sub/cgrp1     9619:looper1
       0.35%  4/0xf00002f5           /sub/cgrp2     9618:cgtest
       0.34%  4/0xf00002f4           /sub/cgrp1     9617:cgtest
       0.32%  4/0xeffffffb           /              9615:looper0
       0.11%  4/0xeffffffb           /sub           9617:cgtest
       0.10%  4/0xeffffffb           /sub           9618:cgtest

  #
  # (Tip: Sample related events with: perf record -e '{cycles,instructions}:S')
  #
  [root@seventh ~]#

Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lore.kernel.org/lkml/20200325124536.2800725-8-namhyung@kernel.org
Link: http://lore.kernel.org/lkml/20200402015249.3800462-1-namhyung@kernel.org
[ Extracted the HAVE_FILE_HANDLE from the followup patch ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
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