<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/tools/perf/util, branch v4.16.2</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: Fix trigger class trigger_on()</title>
<updated>2018-03-06T14:31:14+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2018-02-28T08:39:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=de19e5c3c51fdb1ff20d0f61d099db902ff7494b'/>
<id>de19e5c3c51fdb1ff20d0f61d099db902ff7494b</id>
<content type='text'>
trigger_on() means that the trigger is available but not ready, however
trigger_on() was making it ready. That can segfault if the signal comes
before trigger_ready(). e.g. (USR2 signal delivery not shown)

  $ perf record -e intel_pt//u -S sleep 1
  perf: Segmentation fault
  Obtained 16 stack frames.
  /home/ahunter/bin/perf(sighandler_dump_stack+0x40) [0x4ec550]
  /lib/x86_64-linux-gnu/libc.so.6(+0x36caf) [0x7fa76411acaf]
  /home/ahunter/bin/perf(perf_evsel__disable+0x26) [0x4b9dd6]
  /home/ahunter/bin/perf() [0x43a45b]
  /lib/x86_64-linux-gnu/libc.so.6(+0x36caf) [0x7fa76411acaf]
  /lib/x86_64-linux-gnu/libc.so.6(__xstat64+0x15) [0x7fa7641d2cc5]
  /home/ahunter/bin/perf() [0x4ec6c9]
  /home/ahunter/bin/perf() [0x4ec73b]
  /home/ahunter/bin/perf() [0x4ec73b]
  /home/ahunter/bin/perf() [0x4ec73b]
  /home/ahunter/bin/perf() [0x4eca15]
  /home/ahunter/bin/perf(machine__create_kernel_maps+0x257) [0x4f0b77]
  /home/ahunter/bin/perf(perf_session__new+0xc0) [0x4f86f0]
  /home/ahunter/bin/perf(cmd_record+0x722) [0x43c132]
  /home/ahunter/bin/perf() [0x4a11ae]
  /home/ahunter/bin/perf(main+0x5d4) [0x427fb4]

Note, for testing purposes, this is hard to hit unless you add some sleep()
in builtin-record.c before record__open().

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Cc: stable@vger.kernel.org
Fixes: 3dcc4436fa6f ("perf tools: Introduce trigger class")
Link: http://lkml.kernel.org/r/1519807144-30694-1-git-send-email-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>
trigger_on() means that the trigger is available but not ready, however
trigger_on() was making it ready. That can segfault if the signal comes
before trigger_ready(). e.g. (USR2 signal delivery not shown)

  $ perf record -e intel_pt//u -S sleep 1
  perf: Segmentation fault
  Obtained 16 stack frames.
  /home/ahunter/bin/perf(sighandler_dump_stack+0x40) [0x4ec550]
  /lib/x86_64-linux-gnu/libc.so.6(+0x36caf) [0x7fa76411acaf]
  /home/ahunter/bin/perf(perf_evsel__disable+0x26) [0x4b9dd6]
  /home/ahunter/bin/perf() [0x43a45b]
  /lib/x86_64-linux-gnu/libc.so.6(+0x36caf) [0x7fa76411acaf]
  /lib/x86_64-linux-gnu/libc.so.6(__xstat64+0x15) [0x7fa7641d2cc5]
  /home/ahunter/bin/perf() [0x4ec6c9]
  /home/ahunter/bin/perf() [0x4ec73b]
  /home/ahunter/bin/perf() [0x4ec73b]
  /home/ahunter/bin/perf() [0x4ec73b]
  /home/ahunter/bin/perf() [0x4eca15]
  /home/ahunter/bin/perf(machine__create_kernel_maps+0x257) [0x4f0b77]
  /home/ahunter/bin/perf(perf_session__new+0xc0) [0x4f86f0]
  /home/ahunter/bin/perf(cmd_record+0x722) [0x43c132]
  /home/ahunter/bin/perf() [0x4a11ae]
  /home/ahunter/bin/perf(main+0x5d4) [0x427fb4]

Note, for testing purposes, this is hard to hit unless you add some sleep()
in builtin-record.c before record__open().

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Cc: stable@vger.kernel.org
Fixes: 3dcc4436fa6f ("perf tools: Introduce trigger class")
Link: http://lkml.kernel.org/r/1519807144-30694-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf auxtrace: Prevent decoding when --no-itrace</title>
<updated>2018-03-06T14:05:47+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2018-03-06T09:13:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2e2967f4c398e0f984a6c04daa3a79512e2bb74e'/>
<id>2e2967f4c398e0f984a6c04daa3a79512e2bb74e</id>
<content type='text'>
Prevent auxtrace_queues__process_index() from queuing AUX area data for
decoding when the --no-itrace option has been used.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Link: http://lkml.kernel.org/r/1520327598-1317-3-git-send-email-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>
Prevent auxtrace_queues__process_index() from queuing AUX area data for
decoding when the --no-itrace option has been used.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Link: http://lkml.kernel.org/r/1520327598-1317-3-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf record: Fix crash in pipe mode</title>
<updated>2018-03-05T14:52:41+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2018-03-02T16:13:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cfacbabd1d9c35d2a179650b2911f17a8d8620b8'/>
<id>cfacbabd1d9c35d2a179650b2911f17a8d8620b8</id>
<content type='text'>
Currently we can crash perf record when running in pipe mode, like:

  $ perf record ls | perf report
  # To display the perf.data header info, please use --header/--header-only options.
  #
  perf: Segmentation fault
  Error:
  The - file has no samples!

The callstack of the crash is:

    0x0000000000515242 in perf_event__synthesize_event_update_name
  3513            ev = event_update_event__new(len + 1, PERF_EVENT_UPDATE__NAME, evsel-&gt;id[0]);
  (gdb) bt
  #0  0x0000000000515242 in perf_event__synthesize_event_update_name
  #1  0x00000000005158a4 in perf_event__synthesize_extra_attr
  #2  0x0000000000443347 in record__synthesize
  #3  0x00000000004438e3 in __cmd_record
  #4  0x000000000044514e in cmd_record
  #5  0x00000000004cbc95 in run_builtin
  #6  0x00000000004cbf02 in handle_internal_command
  #7  0x00000000004cc054 in run_argv
  #8  0x00000000004cc422 in main

The reason of the crash is that the evsel does not have ids array
allocated and the pipe's synthesize code tries to access it.

We don't force evsel ids allocation when we have single event, because
it's not needed. However we need it when we are in pipe mode even for
single event as a key for evsel update event.

Fixing this by forcing evsel ids allocation event for single event, when
we are in pipe mode.

Signed-off-by: Jiri Olsa &lt;jolsa@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: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/20180302161354.30192-1-jolsa@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>
Currently we can crash perf record when running in pipe mode, like:

  $ perf record ls | perf report
  # To display the perf.data header info, please use --header/--header-only options.
  #
  perf: Segmentation fault
  Error:
  The - file has no samples!

The callstack of the crash is:

    0x0000000000515242 in perf_event__synthesize_event_update_name
  3513            ev = event_update_event__new(len + 1, PERF_EVENT_UPDATE__NAME, evsel-&gt;id[0]);
  (gdb) bt
  #0  0x0000000000515242 in perf_event__synthesize_event_update_name
  #1  0x00000000005158a4 in perf_event__synthesize_extra_attr
  #2  0x0000000000443347 in record__synthesize
  #3  0x00000000004438e3 in __cmd_record
  #4  0x000000000044514e in cmd_record
  #5  0x00000000004cbc95 in run_builtin
  #6  0x00000000004cbf02 in handle_internal_command
  #7  0x00000000004cc054 in run_argv
  #8  0x00000000004cc422 in main

The reason of the crash is that the evsel does not have ids array
allocated and the pipe's synthesize code tries to access it.

We don't force evsel ids allocation when we have single event, because
it's not needed. However we need it when we are in pipe mode even for
single event as a key for evsel update event.

Fixing this by forcing evsel ids allocation event for single event, when
we are in pipe mode.

Signed-off-by: Jiri Olsa &lt;jolsa@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: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/20180302161354.30192-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Substitute yet another strtoull()</title>
<updated>2018-02-15T12:57:19+00:00</updated>
<author>
<name>Andy Shevchenko</name>
<email>andriy.shevchenko@linux.intel.com</email>
</author>
<published>2018-01-29T13:03:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6677d26c8befa462eab9be6c5335a939011e7e65'/>
<id>6677d26c8befa462eab9be6c5335a939011e7e65</id>
<content type='text'>
Instead of home grown function let's use what library provides us.

Signed-off-by: Andriy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: http://lkml.kernel.org/r/20180129130359.1490-1-andriy.shevchenko@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>
Instead of home grown function let's use what library provides us.

Signed-off-by: Andriy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Link: http://lkml.kernel.org/r/20180129130359.1490-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf hists browser: Add parameter to disable lost event warning</title>
<updated>2018-02-15T12:56:26+00:00</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@intel.com</email>
</author>
<published>2018-01-18T21:26:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=06cc1a470ab237b991901729b125404c164f3660'/>
<id>06cc1a470ab237b991901729b125404c164f3660</id>
<content type='text'>
For overwrite mode, the ringbuffer will be paused. The event lost is
expected. It needs a way to notify the browser not print the warning.

It will be used later for perf top to disable lost event warning in
overwrite mode. There is no behavior change for now.

Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1516310792-208685-15-git-send-email-kan.liang@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>
For overwrite mode, the ringbuffer will be paused. The event lost is
expected. It needs a way to notify the browser not print the warning.

It will be used later for perf top to disable lost event warning in
overwrite mode. There is no behavior change for now.

Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1516310792-208685-15-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf evsel: Expose the perf_missing_features struct</title>
<updated>2018-02-15T12:54:53+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2018-02-02T14:27:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9a831b3a32c5daf5d7cc672334d51930f78e4ea3'/>
<id>9a831b3a32c5daf5d7cc672334d51930f78e4ea3</id>
<content type='text'>
As tools may need to adjust to missing features, as 'perf top' will, in
the next csets, to cope with a missing 'write_backward' feature.

Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: https://lkml.kernel.org/n/tip-jelngl9q1ooaizvkcput9tic@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>
As tools may need to adjust to missing features, as 'perf top' will, in
the next csets, to cope with a missing 'write_backward' feature.

Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Kan Liang &lt;kan.liang@intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: https://lkml.kernel.org/n/tip-jelngl9q1ooaizvkcput9tic@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf mmap: Discard legacy interface for mmap read</title>
<updated>2018-02-15T12:54:17+00:00</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@intel.com</email>
</author>
<published>2018-01-18T21:26:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3effc2f165a842d640873e29d4c5cc1650143aef'/>
<id>3effc2f165a842d640873e29d4c5cc1650143aef</id>
<content type='text'>
Discards perf_mmap__read_backward() and perf_mmap__read_catchup(). No
tools use them.

There are tools still use perf_mmap__read_forward(). Keep it, but add
comments to point to the new interface for future use.

Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1516310792-208685-11-git-send-email-kan.liang@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>
Discards perf_mmap__read_backward() and perf_mmap__read_catchup(). No
tools use them.

There are tools still use perf_mmap__read_forward(). Keep it, but add
comments to point to the new interface for future use.

Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1516310792-208685-11-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf mmap: Introduce perf_mmap__read_event()</title>
<updated>2018-02-15T12:53:40+00:00</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@intel.com</email>
</author>
<published>2018-01-18T21:26:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7bb45972952db9298fe5cc440160dcad1a66bfbc'/>
<id>7bb45972952db9298fe5cc440160dcad1a66bfbc</id>
<content type='text'>
Except for 'perf record', the other perf tools read events one by one
from the ring buffer using perf_mmap__read_forward(). But it only
supports non-overwrite mode.

Introduce perf_mmap__read_event() to support both non-overwrite and
overwrite mode.

Usage:
perf_mmap__read_init()
while(event = perf_mmap__read_event()) {
        //process the event
        perf_mmap__consume()
}
perf_mmap__read_done()

It cannot use perf_mmap__read_backward(). Because it always reads the
stale buffer which is already processed. Furthermore, the forward and
backward concepts have been removed. The perf_mmap__read_backward() will
be replaced and discarded later.

Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1516310792-208685-9-git-send-email-kan.liang@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>
Except for 'perf record', the other perf tools read events one by one
from the ring buffer using perf_mmap__read_forward(). But it only
supports non-overwrite mode.

Introduce perf_mmap__read_event() to support both non-overwrite and
overwrite mode.

Usage:
perf_mmap__read_init()
while(event = perf_mmap__read_event()) {
        //process the event
        perf_mmap__consume()
}
perf_mmap__read_done()

It cannot use perf_mmap__read_backward(). Because it always reads the
stale buffer which is already processed. Furthermore, the forward and
backward concepts have been removed. The perf_mmap__read_backward() will
be replaced and discarded later.

Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1516310792-208685-9-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf mmap: Introduce perf_mmap__read_done()</title>
<updated>2018-02-15T12:53:15+00:00</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@intel.com</email>
</author>
<published>2018-01-18T21:26:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ee023de05f35484691f7d9e5c1f92195ac4d64d2'/>
<id>ee023de05f35484691f7d9e5c1f92195ac4d64d2</id>
<content type='text'>
The direction of overwrite mode is backward. The last perf_mmap__read()
will set tail to map-&gt;prev. Need to correct the map-&gt;prev to head which
is the end of next read.

It will be used later.

Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1516310792-208685-8-git-send-email-kan.liang@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>
The direction of overwrite mode is backward. The last perf_mmap__read()
will set tail to map-&gt;prev. Need to correct the map-&gt;prev to head which
is the end of next read.

It will be used later.

Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1516310792-208685-8-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf mmap: Discard 'prev' in perf_mmap__read()</title>
<updated>2018-02-15T12:53:06+00:00</updated>
<author>
<name>Kan Liang</name>
<email>kan.liang@intel.com</email>
</author>
<published>2018-01-18T21:26:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b4b036b4c76341a5034e872aca3727c4988a7304'/>
<id>b4b036b4c76341a5034e872aca3727c4988a7304</id>
<content type='text'>
The 'start' and 'prev' variables are duplicates in perf_mmap__read().

Use 'map-&gt;prev' to replace 'start' in perf_mmap__read_*().

Suggested-by: Wang Nan &lt;wangnan0@huawei.com&gt;
Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1516310792-208685-7-git-send-email-kan.liang@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>
The 'start' and 'prev' variables are duplicates in perf_mmap__read().

Use 'map-&gt;prev' to replace 'start' in perf_mmap__read_*().

Suggested-by: Wang Nan &lt;wangnan0@huawei.com&gt;
Signed-off-by: Kan Liang &lt;kan.liang@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: Jin Yao &lt;yao.jin@linux.intel.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1516310792-208685-7-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
