<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/tools/perf/Documentation/perf-record.txt, branch linux-6.2.y</title>
<subtitle>Hosts the 0x221E linux distro kernel.</subtitle>
<id>https://universe.0xinfinity.dev/distro/kernel/atom?h=linux-6.2.y</id>
<link rel='self' href='https://universe.0xinfinity.dev/distro/kernel/atom?h=linux-6.2.y'/>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/'/>
<updated>2022-12-14T18:28:18Z</updated>
<entry>
<title>perf evlist: Remove group option.</title>
<updated>2022-12-14T18:28:18Z</updated>
<author>
<name>Ian Rogers</name>
<email>irogers@google.com</email>
</author>
<published>2022-12-13T23:26:51Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=5f8f95673f68914419e8657b3263736264b40e16'/>
<id>urn:sha1:5f8f95673f68914419e8657b3263736264b40e16</id>
<content type='text'>
The group option predates grouping events using curly braces added in
commit 89efb029502d7f2d ("perf tools: Add support to parse event group
syntax").

The --group option was retained for legacy support (in August
2012) but keeping it adds complexity.

Signed-off-by: Ian Rogers &lt;irogers@google.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Alexey Bayduraev &lt;alexey.v.bayduraev@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Anshuman Khandual &lt;anshuman.khandual@arm.com&gt;
Cc: Athira Jajeev &lt;atrajeev@linux.vnet.ibm.com&gt;
Cc: Eelco Chaudron &lt;echaudro@redhat.com&gt;
Cc: German Gomez &lt;german.gomez@arm.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: James Clark &lt;james.clark@arm.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Kim Phillips &lt;kim.phillips@amd.com&gt;
Cc: Leo Yan &lt;leo.yan@linaro.org&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: Riccardo Mancini &lt;rickyman7@gmail.com&gt;
Cc: Sandipan Das &lt;sandipan.das@amd.com&gt;
Cc: Sean Christopherson &lt;seanjc@google.com&gt;
Cc: Shaomin Deng &lt;dengshaomin@cdjrlc.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Cc: Timothy Hayes &lt;timothy.hayes@arm.com&gt;
Cc: Xing Zhengjun &lt;zhengjun.xing@linux.intel.com&gt;
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20221213232651.1269909-6-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Add remaining branch filters: "no_cycles", "no_flags" &amp; "hw_index"</title>
<updated>2022-12-14T14:16:12Z</updated>
<author>
<name>Anshuman Khandual</name>
<email>anshuman.khandual@arm.com</email>
</author>
<published>2022-12-05T06:44:43Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=955f6def5590ce6ca11a1c1ced0d2d1c95421059'/>
<id>urn:sha1:955f6def5590ce6ca11a1c1ced0d2d1c95421059</id>
<content type='text'>
This adds all remaining branch filters i.e "no_cycles", "no_flags" and
"hw_index". While here, also updates the documentation.

Signed-off-by: Anshuman Khandual &lt;anshuman.khandual@arm.com&gt;
Cc: James Clark &lt;james.clark@arm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lore.kernel.org/lkml/20221205064443.533587-1-anshuman.khandual@arm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf tools: Make quiet mode consistent between tools</title>
<updated>2022-10-27T19:37:26Z</updated>
<author>
<name>James Clark</name>
<email>james.clark@arm.com</email>
</author>
<published>2022-10-18T09:41:36Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=a527c2c1e2d43e9f145f5d0c5d6ac0bdf5220e22'/>
<id>urn:sha1:a527c2c1e2d43e9f145f5d0c5d6ac0bdf5220e22</id>
<content type='text'>
Use the global quiet variable everywhere so that all tools hide warnings
in quiet mode and update the documentation to reflect this.

'perf probe' claimed that errors are not printed in quiet mode but I
don't see this so remove it from the docs.

Signed-off-by: James Clark &lt;james.clark@arm.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&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;
Link: https://lore.kernel.org/r/20221018094137.783081-3-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf mem/c2c: Set PERF_SAMPLE_WEIGHT for LOAD_STORE events</title>
<updated>2022-10-06T19:29:32Z</updated>
<author>
<name>Ravi Bangoria</name>
<email>ravi.bangoria@amd.com</email>
</author>
<published>2022-10-06T15:39:42Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=4173cc055dc92f199a43775775e54dc7fafd37b6'/>
<id>urn:sha1:4173cc055dc92f199a43775775e54dc7fafd37b6</id>
<content type='text'>
Currently perf sets PERF_SAMPLE_WEIGHT flag only for mem load events.
Set it for combined load-store event as well which will enable recording
of load latency by default on arch that does not support independent
mem load event.

Also document missing -W in perf-record man page.

Signed-off-by: Ravi Bangoria &lt;ravi.bangoria@amd.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Ali Saidi &lt;alisaidi@amazon.com&gt;
Cc: Ananth Narayan &lt;ananth.narayan@amd.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Joe Mario &lt;jmario@redhat.com&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Kim Phillips &lt;kim.phillips@amd.com&gt;
Cc: Leo Yan &lt;leo.yan@linaro.org&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: Sandipan Das &lt;sandipan.das@amd.com&gt;
Cc: Santosh Shukla &lt;santosh.shukla@amd.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: x86@kernel.org
Link: https://lore.kernel.org/r/20221006153946.7816-5-ravi.bangoria@amd.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf branch: Add branch privilege information request flag</title>
<updated>2022-10-04T11:55:20Z</updated>
<author>
<name>Anshuman Khandual</name>
<email>anshuman.khandual@arm.com</email>
</author>
<published>2022-08-24T04:48:21Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=bcb96ce6d2544ae0738cf54fd0a6d048fad791ec'/>
<id>urn:sha1:bcb96ce6d2544ae0738cf54fd0a6d048fad791ec</id>
<content type='text'>
This updates the perf tools with branch privilege information request flag
i.e PERF_SAMPLE_BRANCH_PRIV_SAVE that has been added earlier in the kernel.
This also updates 'perf record' documentation, branch_modes[], and generic
branch privilege level enumeration as added earlier in the kernel.

Signed-off-by: Anshuman Khandual &lt;anshuman.khandual@arm.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: James Clark &lt;james.clark@arm.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&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: Robin Murphy &lt;robin.murphy@arm.com&gt;
Cc: Suzuki Poulouse &lt;suzuki.poulose@arm.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220824044822.70230-8-anshuman.khandual@arm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Allow multiple recording time ranges</title>
<updated>2022-10-04T11:55:19Z</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2022-08-24T07:28:14Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=6657a099e1858e4a39b501c38c16c6ef77c71a5a'/>
<id>urn:sha1:6657a099e1858e4a39b501c38c16c6ef77c71a5a</id>
<content type='text'>
AUX area traces can produce too much data to record successfully or
analyze subsequently. Add another means to reduce data collection by
allowing multiple recording time ranges.

This is useful, for instance, in cases where a workload produces
predictably reproducible events in specific time ranges.

Today we only have perf record -D &lt;msecs&gt; to start at a specific region, or
some complicated approach using snapshot mode and external scripts sending
signals or using the fifos. But these approaches are difficult to set up
compared with simply having perf do it.

Extend perf record option -D/--delay option to specifying relative time
stamps for start stop controlled by perf with the right time offset, for
instance:

    perf record -e intel_pt// -D 10-20,30-40

to record 10ms to 20ms into the trace and 30ms to 40ms.

Example:

 The example workload is:

 $ cat repeat-usleep.c

 int usleep(useconds_t usec);

 int usage(int ret, const char *msg)
 {
         if (msg)
                 fprintf(stderr, "%s\n", msg);

         fprintf(stderr, "Usage is: repeat-usleep &lt;microseconds&gt;\n");

         return ret;
 }

 int main(int argc, char *argv[])
 {
         unsigned long usecs;
         char *end_ptr;

         if (argc != 2)
                 return usage(1, "Error: Wrong number of arguments!");

         errno = 0;
         usecs = strtoul(argv[1], &amp;end_ptr, 0);
         if (errno || *end_ptr || usecs &gt; UINT_MAX)
                 return usage(1, "Error: Invalid argument!");

         while (1) {
                 int ret = usleep(usecs);

                 if (ret &amp; errno != EINTR)
                         return usage(1, "Error: usleep() failed!");
         }

         return 0;
 }

 $ perf record -e intel_pt//u --delay 10-20,40-70,110-160 -- ./repeat-usleep 500
 Events disabled
 Events enabled
 Events disabled
 Events enabled
 Events disabled
 Events enabled
 Events disabled
 [ perf record: Woken up 5 times to write data ]
 [ perf record: Captured and wrote 0.204 MB perf.data ]
 Terminated

 A dlfilter is used to determine continuous data collection (timestamps
 less than 1ms apart):

 $ cat dlfilter-show-delays.c

 static __u64 start_time;
 static __u64 last_time;

 int start(void **data, void *ctx)
 {
         printf("%-17s\t%-9s\t%-6s\n", " Time", " Duration", " Delay");
         return 0;
 }

 int filter_event_early(void *data, const struct perf_dlfilter_sample *sample, void *ctx)
 {
         __u64 delta;

         if (!sample-&gt;time)
                 return 1;
         if (!last_time)
                 goto out;
         delta = sample-&gt;time - last_time;
         if (delta &lt; 1000000)
                 goto out2;;
         printf("%17.9f\t%9.1f\t%6.1f\n", start_time / 1000000000.0, (last_time - start_time) / 1000000.0, delta / 1000000.0);
 out:
         start_time = sample-&gt;time;
 out2:
         last_time = sample-&gt;time;
         return 1;
 }

 int stop(void *data, void *ctx)
 {
         printf("%17.9f\t%9.1f\n", start_time / 1000000000.0, (last_time - start_time) / 1000000.0);
         return 0;
 }

 The result shows the times roughly match the --delay option:

 $ perf script --itrace=qb --dlfilter dlfilter-show-delays.so
  Time                    Duration        Delay
   39215.302317300             9.7         20.5
   39215.332480217            30.4         40.9
   39215.403837717            49.8

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexey Bayduraev &lt;alexey.v.bayduraev@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: https://lore.kernel.org/r/20220824072814.16422-6-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf docs: Update the documentation for the save_type filter</title>
<updated>2022-08-27T14:55:17Z</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@linux.intel.com</email>
</author>
<published>2022-08-16T12:56:12Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=3126204ce3d9ab083cbdc2d61ab93746232eb89b'/>
<id>urn:sha1:3126204ce3d9ab083cbdc2d61ab93746232eb89b</id>
<content type='text'>
Update the documentation to reflect the kernel changes.

Signed-off-by: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: https://lore.kernel.org/r/20220816125612.2042397-2-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Fix manpage formatting of description of support to hybrid systems</title>
<updated>2022-08-27T14:55:17Z</updated>
<author>
<name>Andi Kleen</name>
<email>ak@linux.intel.com</email>
</author>
<published>2022-08-18T10:01:27Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=e89eaa611c7568d1288a2ccca88355a9434f2d47'/>
<id>urn:sha1:e89eaa611c7568d1288a2ccca88355a9434f2d47</id>
<content type='text'>
The Intel hybrid description is written in a different style than the
rest of the perf record man page. There were some new command line
options added after it which resulted in very strange section ordering.
Move the hybrid include last.

Also the sub sections in the hybrid document don't fit the record
manpage well (especially since it talks about all kinds of unrelated
commands). I left this for now, but would be better to separate this
properly in the different man pages.

It would be better to use sub sections for the other sections, but these
don't seem to be supported in AsciiDoc?

Some of the examples are still misrendered in the manpage with an
indented troff command, but I don't know how to fix that.

In any case it's now better than before.

Signed-off-by: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: zhengjun.xing@intel.com
Link: https://lore.kernel.org/r/20220818100127.249401-1-ak@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Allow to specify max stack depth of fp callchain</title>
<updated>2022-07-12T12:56:05Z</updated>
<author>
<name>Namhyung Kim</name>
<email>namhyung@kernel.org</email>
</author>
<published>2022-06-15T16:32:21Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=7cb2a53f7f413734734bac214c4855e9863b9853'/>
<id>urn:sha1:7cb2a53f7f413734734bac214c4855e9863b9853</id>
<content type='text'>
Currently it has no interface to specify the max stack depth for perf
record.  Extend the command line parameter to accept a number after
'fp' to specify the depth like '--call-graph fp,32'.

Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Boqun Feng &lt;boqun.feng@gmail.com&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Waiman Long &lt;longman@redhat.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Link: https://lore.kernel.org/r/20220615163222.1275500-7-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf record: Add new option to sample identifier</title>
<updated>2022-06-23T14:54:22Z</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2022-06-15T05:25:11Z</published>
<link rel='alternate' type='text/html' href='https://universe.0xinfinity.dev/distro/kernel/commit/?id=61110883a02090cb5fd1f890978e238cc99f0164'/>
<id>urn:sha1:61110883a02090cb5fd1f890978e238cc99f0164</id>
<content type='text'>
In preparation for recording sideband events in a virtual machine guest so
that they can be injected into a host perf.data file.

Add an option to always include sample type PERF_SAMPLE_IDENTIFIER.

Committer testing:

  # perf record sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.020 MB perf.data (7 samples) ]
  # perf evlist -v
  cycles: size: 128, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1
  #
  #
  # perf record --sample-identifier sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.022 MB perf.data (7 samples) ]
  # perf evlist -v
  cycles: size: 128, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD|IDENTIFIER, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, mmap2: 1, comm_exec: 1, ksymbol: 1, bpf_event: 1
  #

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Acked-by: Ian Rogers &lt;irogers@google.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: https://lore.kernel.org/r/20220615052511.4441-1-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
</feed>
