<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/tools/include/uapi/linux/perf_event.h, branch linux-5.6.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>perf tools: Add kernel AUX area sampling definitions</title>
<updated>2019-11-21T13:54:20+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2019-11-15T12:42:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=98dcf14d7f9c9482144b9015d481bf6b63bce965'/>
<id>98dcf14d7f9c9482144b9015d481bf6b63bce965</id>
<content type='text'>
Add kernel AUX area sampling definitions, which brings perf_event.h into
line with the kernel version.

New sample type PERF_SAMPLE_AUX requests a sample of the AUX area
buffer.  New perf_event_attr member 'aux_sample_size' specifies the
desired size of the sample.

Also add support for parsing samples containing AUX area data i.e.
PERF_SAMPLE_AUX.

Committer notes:

I squashed the first two patches in this series to avoid breaking
automatic bisection, i.e. after applying only the original first patch
in this series we would have:

  # perf test -v parsing
  26: Sample parsing                                        :
  --- start ---
  test child forked, pid 17018
  sample format has changed, some new PERF_SAMPLE_ bit was introduced - test needs updating
  test child finished with -1
  ---- end ----
  Sample parsing: FAILED!
  #

With the two paches combined:

  # perf test parsing
  26: Sample parsing                                        : Ok
  #

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Link: http://lore.kernel.org/lkml/20191115124225.5247-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add kernel AUX area sampling definitions, which brings perf_event.h into
line with the kernel version.

New sample type PERF_SAMPLE_AUX requests a sample of the AUX area
buffer.  New perf_event_attr member 'aux_sample_size' specifies the
desired size of the sample.

Also add support for parsing samples containing AUX area data i.e.
PERF_SAMPLE_AUX.

Committer notes:

I squashed the first two patches in this series to avoid breaking
automatic bisection, i.e. after applying only the original first patch
in this series we would have:

  # perf test -v parsing
  26: Sample parsing                                        :
  --- start ---
  test child forked, pid 17018
  sample format has changed, some new PERF_SAMPLE_ bit was introduced - test needs updating
  test child finished with -1
  ---- end ----
  Sample parsing: FAILED!
  #

With the two paches combined:

  # perf test parsing
  26: Sample parsing                                        : Ok
  #

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Link: http://lore.kernel.org/lkml/20191115124225.5247-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Add aux_output attribute flag</title>
<updated>2019-08-14T13:59:59+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2019-08-06T08:46:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5a4b58e5d64ac7ebca175ffd8d74ca1b5cb0a01f'/>
<id>5a4b58e5d64ac7ebca175ffd8d74ca1b5cb0a01f</id>
<content type='text'>
Add aux_output attribute flag to match the kernel's perf_event.h file.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/20190806084606.4021-4-alexander.shishkin@linux.intel.com
Signed-off-by: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add aux_output attribute flag to match the kernel's perf_event.h file.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/20190806084606.4021-4-alexander.shishkin@linux.intel.com
Signed-off-by: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools headers uapi: Sync tools/include/uapi/linux/perf_event.h</title>
<updated>2019-01-21T20:00:57+00:00</updated>
<author>
<name>Song Liu</name>
<email>songliubraving@fb.com</email>
</author>
<published>2019-01-17T16:15:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=df063c83aa2c58412ddf533ada9aaf25986120ec'/>
<id>df063c83aa2c58412ddf533ada9aaf25986120ec</id>
<content type='text'>
Sync for PERF_RECORD_BPF_EVENT.

Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Reviewed-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: kernel-team@fb.com
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20190117161521.1341602-5-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Sync for PERF_RECORD_BPF_EVENT.

Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Reviewed-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: kernel-team@fb.com
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20190117161521.1341602-5-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools headers uapi: Sync tools/include/uapi/linux/perf_event.h</title>
<updated>2019-01-21T20:00:57+00:00</updated>
<author>
<name>Song Liu</name>
<email>songliubraving@fb.com</email>
</author>
<published>2019-01-17T16:15:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d764ac6464915523e68e220b6aa4c3c2eb8e3f94'/>
<id>d764ac6464915523e68e220b6aa4c3c2eb8e3f94</id>
<content type='text'>
Sync changes for PERF_RECORD_KSYMBOL.

Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Reviewed-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: kernel-team@fb.com
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20190117161521.1341602-3-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Sync changes for PERF_RECORD_KSYMBOL.

Signed-off-by: Song Liu &lt;songliubraving@fb.com&gt;
Reviewed-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Alexei Starovoitov &lt;ast@kernel.org&gt;
Cc: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: kernel-team@fb.com
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20190117161521.1341602-3-songliubraving@fb.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf/core: Remove unused perf_flags</title>
<updated>2019-01-21T10:01:31+00:00</updated>
<author>
<name>Andrew Murray</name>
<email>andrew.murray@arm.com</email>
</author>
<published>2019-01-10T13:53:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ad07c8ceb6631a83b62d405a61448bba92adac68'/>
<id>ad07c8ceb6631a83b62d405a61448bba92adac68</id>
<content type='text'>
Now that perf_flags is not used we remove it.

Signed-off-by: Andrew Murray &lt;andrew.murray@arm.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Ivan Kokshaysky &lt;ink@jurassic.park.msu.ru&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Matt Turner &lt;mattst88@gmail.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Richard Henderson &lt;rth@twiddle.net&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Sascha Hauer &lt;s.hauer@pengutronix.de&gt;
Cc: Shawn Guo &lt;shawnguo@kernel.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: robin.murphy@arm.com
Cc: suzuki.poulose@arm.com
Link: https://lkml.kernel.org/r/1547128414-50693-13-git-send-email-andrew.murray@arm.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Now that perf_flags is not used we remove it.

Signed-off-by: Andrew Murray &lt;andrew.murray@arm.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Ivan Kokshaysky &lt;ink@jurassic.park.msu.ru&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Matt Turner &lt;mattst88@gmail.com&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Richard Henderson &lt;rth@twiddle.net&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Sascha Hauer &lt;s.hauer@pengutronix.de&gt;
Cc: Shawn Guo &lt;shawnguo@kernel.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: robin.murphy@arm.com
Cc: suzuki.poulose@arm.com
Link: https://lkml.kernel.org/r/1547128414-50693-13-git-send-email-andrew.murray@arm.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Don't clone maps from parent when synthesizing forks</title>
<updated>2018-10-31T13:18:01+00:00</updated>
<author>
<name>David Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2018-10-31T05:24:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4f8f382e635707ddaddf8269a116e4f8cc8835c0'/>
<id>4f8f382e635707ddaddf8269a116e4f8cc8835c0</id>
<content type='text'>
When synthesizing FORK events, we are trying to create thread objects
for the already running tasks on the machine.

Normally, for a kernel FORK event, we want to clone the parent's maps
because that is what the kernel just did.

But when synthesizing, this should not be done.  If we do, we end up
with overlapping maps as we process the sythesized MMAP2 events that
get delivered shortly thereafter.

Use the FORK event misc flags in an internal way to signal this
situation, so we can elide the map clone when appropriate.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Don Zickus &lt;dzickus@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Joe Mario &lt;jmario@redhat.com&gt;
Link: http://lkml.kernel.org/r/20181030.222404.2085088822877051075.davem@davemloft.net
[ Added comment about flag use in machine__process_fork_event(),
  use ternary op in thread__clone_map_groups() as suggested by Jiri ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When synthesizing FORK events, we are trying to create thread objects
for the already running tasks on the machine.

Normally, for a kernel FORK event, we want to clone the parent's maps
because that is what the kernel just did.

But when synthesizing, this should not be done.  If we do, we end up
with overlapping maps as we process the sythesized MMAP2 events that
get delivered shortly thereafter.

Use the FORK event misc flags in an internal way to signal this
situation, so we can elide the map clone when appropriate.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Don Zickus &lt;dzickus@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Joe Mario &lt;jmario@redhat.com&gt;
Link: http://lkml.kernel.org/r/20181030.222404.2085088822877051075.davem@davemloft.net
[ Added comment about flag use in machine__process_fork_event(),
  use ternary op in thread__clone_map_groups() as suggested by Jiri ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools headers uapi: Update tools's copy of linux/perf_event.h</title>
<updated>2018-09-11T13:57:13+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2018-09-11T13:57:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0ee03d936cbb300309ed6154ac1cc12b63e9785f'/>
<id>0ee03d936cbb300309ed6154ac1cc12b63e9785f</id>
<content type='text'>
To get the changes in:

	09121255c784 ("perf/UAPI: Clearly mark __PERF_SAMPLE_CALLCHAIN_EARLY as internal use")

This cures the following warning during perf's build:

	Warning: Kernel ABI header at 'tools/include/uapi/linux/perf_event.h' differs from latest version at 'include/uapi/linux/perf_event.h'
	diff -u tools/include/uapi/linux/perf_event.h include/uapi/linux/perf_event.h

Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: https://lkml.kernel.org/n/tip-2vvwh2o19orn56di0ksrtgzr@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
To get the changes in:

	09121255c784 ("perf/UAPI: Clearly mark __PERF_SAMPLE_CALLCHAIN_EARLY as internal use")

This cures the following warning during perf's build:

	Warning: Kernel ABI header at 'tools/include/uapi/linux/perf_event.h' differs from latest version at 'include/uapi/linux/perf_event.h'
	diff -u tools/include/uapi/linux/perf_event.h include/uapi/linux/perf_event.h

Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: https://lkml.kernel.org/n/tip-2vvwh2o19orn56di0ksrtgzr@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools headers uapi: Update tools's copy of linux/perf_event.h</title>
<updated>2018-07-30T14:41:56+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2018-07-30T14:41:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2c3ee0e1779d2e08bc08734bc8475daaf94d0ba4'/>
<id>2c3ee0e1779d2e08bc08734bc8475daaf94d0ba4</id>
<content type='text'>
To get the changes in:

  6cbc304f2f36 ("perf/x86/intel: Fix unwind errors from PEBS entries (mk-II)")

That do not imply any changes in the tooling side, the (ab)use of
sample_type is entirely done in kernel space, nothing for userspace to
witness here.

This cures the following warning during perf's build:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/perf_event.h' differs from latest version at 'include/uapi/linux/perf_event.h'

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Prashant Bhole &lt;bhole_prashant_q7@lab.ntt.co.jp&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vince Weaver &lt;vincent.weaver@maine.edu&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: https://lkml.kernel.org/n/tip-o64mjoy35s9gd1gitunw1zg4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
To get the changes in:

  6cbc304f2f36 ("perf/x86/intel: Fix unwind errors from PEBS entries (mk-II)")

That do not imply any changes in the tooling side, the (ab)use of
sample_type is entirely done in kernel space, nothing for userspace to
witness here.

This cures the following warning during perf's build:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/perf_event.h' differs from latest version at 'include/uapi/linux/perf_event.h'

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Prashant Bhole &lt;bhole_prashant_q7@lab.ntt.co.jp&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vince Weaver &lt;vincent.weaver@maine.edu&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: https://lkml.kernel.org/n/tip-o64mjoy35s9gd1gitunw1zg4@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf/core: Store context switch out type in PERF_RECORD_SWITCH[_CPU_WIDE]</title>
<updated>2018-04-17T12:47:39+00:00</updated>
<author>
<name>Alexey Budankov</name>
<email>alexey.budankov@linux.intel.com</email>
</author>
<published>2018-04-09T07:25:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=101592b4904ecf6b8ed2a4784d41d180319d95a1'/>
<id>101592b4904ecf6b8ed2a4784d41d180319d95a1</id>
<content type='text'>
Store preempting context switch out event into Perf trace as a part of
PERF_RECORD_SWITCH[_CPU_WIDE] record.

Percentage of preempting and non-preempting context switches help
understanding the nature of workloads (CPU or IO bound) that are running
on a machine;

The event is treated as preemption one when task-&gt;state value of the
thread being switched out is TASK_RUNNING. Event type encoding is
implemented using PERF_RECORD_MISC_SWITCH_OUT_PREEMPT bit;

Signed-off-by: Alexey Budankov &lt;alexey.budankov@linux.intel.com&gt;
Acked-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: http://lkml.kernel.org/r/9ff84e83-a0ca-dd82-a6d0-cb951689be74@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Store preempting context switch out event into Perf trace as a part of
PERF_RECORD_SWITCH[_CPU_WIDE] record.

Percentage of preempting and non-preempting context switches help
understanding the nature of workloads (CPU or IO bound) that are running
on a machine;

The event is treated as preemption one when task-&gt;state value of the
thread being switched out is TASK_RUNNING. Event type encoding is
implemented using PERF_RECORD_MISC_SWITCH_OUT_PREEMPT bit;

Signed-off-by: Alexey Budankov &lt;alexey.budankov@linux.intel.com&gt;
Acked-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: http://lkml.kernel.org/r/9ff84e83-a0ca-dd82-a6d0-cb951689be74@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf/core: Implement fast breakpoint modification via _IOC_MODIFY_ATTRIBUTES</title>
<updated>2018-03-13T14:24:02+00:00</updated>
<author>
<name>Milind Chabbi</name>
<email>chabbi.milind@gmail.com</email>
</author>
<published>2018-03-12T13:45:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=32ff77e8cc9e66cc4fb38098f64fd54cc8f54573'/>
<id>32ff77e8cc9e66cc4fb38098f64fd54cc8f54573</id>
<content type='text'>
Problem and motivation: Once a breakpoint perf event (PERF_TYPE_BREAKPOINT)
is created, there is no flexibility to change the breakpoint type
(bp_type), breakpoint address (bp_addr), or breakpoint length (bp_len). The
only option is to close the perf event and configure a new breakpoint
event. This inflexibility has a significant performance overhead. For
example, sampling-based, lightweight performance profilers (and also
concurrency bug detection tools),  monitor different addresses for a short
duration using PERF_TYPE_BREAKPOINT and change the address (bp_addr) to
another address or change the kind of breakpoint (bp_type) from  "write" to
a "read" or vice-versa or change the length (bp_len) of the address being
monitored. The cost of these modifications is prohibitive since it involves
unmapping the circular buffer associated with the perf event, closing the
perf event, opening another perf event and mmaping another circular buffer.

Solution: The new ioctl flag for perf events,
PERF_EVENT_IOC_MODIFY_ATTRIBUTES, introduced in this patch takes a pointer
to a struct perf_event_attr as an argument to update an old breakpoint
event with new address, type, and size. This facility allows retaining a
previous mmaped perf events ring buffer and avoids having to close and
reopen another perf event.

This patch supports only changing PERF_TYPE_BREAKPOINT event type; future
implementations can extend this feature. The patch replicates some of its
functionality of modify_user_hw_breakpoint() in
kernel/events/hw_breakpoint.c. modify_user_hw_breakpoint cannot be called
directly since perf_event_ctx_lock() is already held in _perf_ioctl().

Evidence: Experiments show that the baseline (not able to modify an already
created breakpoint) costs an order of magnitude (~10x) more than the
suggested optimization (having the ability to dynamically modifying a
configured breakpoint via ioctl). When the breakpoints typically do not
trap, the speedup due to the suggested optimization is ~10x; even when the
breakpoints always trap, the speedup is ~4x due to the suggested
optimization.

Testing: tests posted at
https://github.com/linux-contrib/perf_event_modify_bp demonstrate the
performance significance of this patch. Tests also check the functional
correctness of the patch.

Signed-off-by: Milind Chabbi &lt;chabbi.milind@gmail.com&gt;
[ Using modify_user_hw_breakpoint_check function. ]
[ Reformated PERF_EVENT_IOC_*, so the values are all in one column. ]
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Hari Bathini &lt;hbathini@linux.vnet.ibm.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Oleg Nesterov &lt;onestero@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Sukadev Bhattiprolu &lt;sukadev@linux.vnet.ibm.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Link: http://lkml.kernel.org/r/20180312134548.31532-8-jolsa@kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Problem and motivation: Once a breakpoint perf event (PERF_TYPE_BREAKPOINT)
is created, there is no flexibility to change the breakpoint type
(bp_type), breakpoint address (bp_addr), or breakpoint length (bp_len). The
only option is to close the perf event and configure a new breakpoint
event. This inflexibility has a significant performance overhead. For
example, sampling-based, lightweight performance profilers (and also
concurrency bug detection tools),  monitor different addresses for a short
duration using PERF_TYPE_BREAKPOINT and change the address (bp_addr) to
another address or change the kind of breakpoint (bp_type) from  "write" to
a "read" or vice-versa or change the length (bp_len) of the address being
monitored. The cost of these modifications is prohibitive since it involves
unmapping the circular buffer associated with the perf event, closing the
perf event, opening another perf event and mmaping another circular buffer.

Solution: The new ioctl flag for perf events,
PERF_EVENT_IOC_MODIFY_ATTRIBUTES, introduced in this patch takes a pointer
to a struct perf_event_attr as an argument to update an old breakpoint
event with new address, type, and size. This facility allows retaining a
previous mmaped perf events ring buffer and avoids having to close and
reopen another perf event.

This patch supports only changing PERF_TYPE_BREAKPOINT event type; future
implementations can extend this feature. The patch replicates some of its
functionality of modify_user_hw_breakpoint() in
kernel/events/hw_breakpoint.c. modify_user_hw_breakpoint cannot be called
directly since perf_event_ctx_lock() is already held in _perf_ioctl().

Evidence: Experiments show that the baseline (not able to modify an already
created breakpoint) costs an order of magnitude (~10x) more than the
suggested optimization (having the ability to dynamically modifying a
configured breakpoint via ioctl). When the breakpoints typically do not
trap, the speedup due to the suggested optimization is ~10x; even when the
breakpoints always trap, the speedup is ~4x due to the suggested
optimization.

Testing: tests posted at
https://github.com/linux-contrib/perf_event_modify_bp demonstrate the
performance significance of this patch. Tests also check the functional
correctness of the patch.

Signed-off-by: Milind Chabbi &lt;chabbi.milind@gmail.com&gt;
[ Using modify_user_hw_breakpoint_check function. ]
[ Reformated PERF_EVENT_IOC_*, so the values are all in one column. ]
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Hari Bathini &lt;hbathini@linux.vnet.ibm.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Oleg Nesterov &lt;onestero@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Sukadev Bhattiprolu &lt;sukadev@linux.vnet.ibm.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Link: http://lkml.kernel.org/r/20180312134548.31532-8-jolsa@kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
