<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/tools/perf/util/thread.h, branch linux-3.14.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 thread: Move comm_list check into function</title>
<updated>2013-11-27T17:58:37+00:00</updated>
<author>
<name>David Ahern</name>
<email>dsahern@gmail.com</email>
</author>
<published>2013-11-18T20:32:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1f3878c11ca8c9f2d9545ec6e1e6bb5386e0565f'/>
<id>1f3878c11ca8c9f2d9545ec6e1e6bb5386e0565f</id>
<content type='text'>
Signed-off-by: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.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: http://lkml.kernel.org/r/1384806771-2945-5-git-send-email-dsahern@gmail.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>
Signed-off-by: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.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: http://lkml.kernel.org/r/1384806771-2945-5-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Finish the removal of 'self' arguments</title>
<updated>2013-11-05T18:32:36+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2013-11-05T18:32:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=316c7136f8bad924609163b9b115f68d59a68c82'/>
<id>316c7136f8bad924609163b9b115f68d59a68c82</id>
<content type='text'>
They convey no information, perhaps I was bitten by some snake at some
point, complete the detox by naming the last of those arguments more
sensibly.

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/n/tip-u1r0dnjoro08dgztiy2g3t2q@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>
They convey no information, perhaps I was bitten by some snake at some
point, complete the detox by naming the last of those arguments more
sensibly.

Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/n/tip-u1r0dnjoro08dgztiy2g3t2q@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Get current comm instead of last one</title>
<updated>2013-11-04T15:16:39+00:00</updated>
<author>
<name>Namhyung Kim</name>
<email>namhyung.kim@lge.com</email>
</author>
<published>2013-09-13T07:28:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4dfced359fbc719a35527416f1b4b3999647f68b'/>
<id>4dfced359fbc719a35527416f1b4b3999647f68b</id>
<content type='text'>
At insert time, a hist entry should reference comm at the time otherwise
it'll get the last comm anyway.

Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Acked-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Tested-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Link: http://lkml.kernel.org/n/tip-n6pykiiymtgmcjs834go2t8x@git.kernel.org
[ Fixed up const pointer issues ]
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>
At insert time, a hist entry should reference comm at the time otherwise
it'll get the last comm anyway.

Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Acked-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Tested-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Link: http://lkml.kernel.org/n/tip-n6pykiiymtgmcjs834go2t8x@git.kernel.org
[ Fixed up const pointer issues ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Add new COMM infrastructure</title>
<updated>2013-11-04T15:13:53+00:00</updated>
<author>
<name>Frederic Weisbecker</name>
<email>fweisbec@gmail.com</email>
</author>
<published>2013-09-11T14:56:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1902efe7f626fdebe1520f5ff11f1309ec506708'/>
<id>1902efe7f626fdebe1520f5ff11f1309ec506708</id>
<content type='text'>
This new COMM infrastructure provides two features:

1) It keeps track of all comms lifecycle for a given thread. This way we
can associate a timeframe to any thread COMM, as long as
PERF_SAMPLE_TIME samples are joined to COMM and fork events.

As a result we should have more precise COMM sorted hists with seperated
entries for pre and post exec time after a fork.

2) It also makes sure that a given COMM string is not duplicated but
rather shared among the threads that refer to it. This way the threads
COMM can be compared against pointer values from the sort
infrastructure.

Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Tested-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/n/tip-hwjf70b2wve9m2kosxiq8bb3@git.kernel.org
[ Rename some accessor functions ]
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
[ Use __ as separator for class__method for private comm_str methods ]
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>
This new COMM infrastructure provides two features:

1) It keeps track of all comms lifecycle for a given thread. This way we
can associate a timeframe to any thread COMM, as long as
PERF_SAMPLE_TIME samples are joined to COMM and fork events.

As a result we should have more precise COMM sorted hists with seperated
entries for pre and post exec time after a fork.

2) It also makes sure that a given COMM string is not duplicated but
rather shared among the threads that refer to it. This way the threads
COMM can be compared against pointer values from the sort
infrastructure.

Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Tested-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/n/tip-hwjf70b2wve9m2kosxiq8bb3@git.kernel.org
[ Rename some accessor functions ]
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
[ Use __ as separator for class__method for private comm_str methods ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Add time argument on COMM setting</title>
<updated>2013-11-04T14:57:06+00:00</updated>
<author>
<name>Frederic Weisbecker</name>
<email>fweisbec@gmail.com</email>
</author>
<published>2013-09-11T14:18:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=162f0befda3becc2cc9f44075fccc030e55baec1'/>
<id>162f0befda3becc2cc9f44075fccc030e55baec1</id>
<content type='text'>
This way we can later delimit a lifecycle for the COMM and map a hist to
a precise COMM:timeslice couple.

PERF_RECORD_COMM and PERF_RECORD_FORK events that don't have
PERF_SAMPLE_TIME samples can only send 0 value as a timestamp and thus
should overwrite any previous COMM on a given thread because there is no
sensible way to keep track of all the comms lifecycles in a thread
without time informations.

Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Tested-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/n/tip-6tyow99vgmmtt9qwr2u2lqd7@git.kernel.org
[ Made it cope with PERF_RECORD_MMAP2 ]
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>
This way we can later delimit a lifecycle for the COMM and map a hist to
a precise COMM:timeslice couple.

PERF_RECORD_COMM and PERF_RECORD_FORK events that don't have
PERF_SAMPLE_TIME samples can only send 0 value as a timestamp and thus
should overwrite any previous COMM on a given thread because there is no
sensible way to keep track of all the comms lifecycles in a thread
without time informations.

Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Tested-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/n/tip-6tyow99vgmmtt9qwr2u2lqd7@git.kernel.org
[ Made it cope with PERF_RECORD_MMAP2 ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Use an accessor to read thread comm</title>
<updated>2013-11-04T14:50:28+00:00</updated>
<author>
<name>Frederic Weisbecker</name>
<email>fweisbec@gmail.com</email>
</author>
<published>2013-09-11T12:46:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b9c5143a012a543c4ee872498d6dbae5c10beb2e'/>
<id>b9c5143a012a543c4ee872498d6dbae5c10beb2e</id>
<content type='text'>
As the thread comm is going to be implemented by way of a more
complicated data structure than just a pointer to a string from the
thread struct, convert the readers of comm to use an accessor instead of
accessing it directly.

The accessor will be later overriden to support an enhanced comm
implementation.

Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Tested-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/n/tip-wr683zwy94hmj4ibogmnv9ce@git.kernel.org
[ Rename thread__comm_curr() to thread__comm_str() ]
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
[ Fixed up some minor const pointer issues ]
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 the thread comm is going to be implemented by way of a more
complicated data structure than just a pointer to a string from the
thread struct, convert the readers of comm to use an accessor instead of
accessing it directly.

The accessor will be later overriden to support an enhanced comm
implementation.

Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Tested-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/n/tip-wr683zwy94hmj4ibogmnv9ce@git.kernel.org
[ Rename thread__comm_curr() to thread__comm_str() ]
Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
[ Fixed up some minor const pointer issues ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Add pid to struct thread</title>
<updated>2013-08-27T14:05:53+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2013-08-26T13:00:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=99d725fc65563a85d4290342c81b00a673c6be66'/>
<id>99d725fc65563a85d4290342c81b00a673c6be66</id>
<content type='text'>
Record pid on struct thread.  The member is named 'pid_' to avoid
confusion with the 'tid' member which was previously named 'pid'.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Acked-by: David Ahern &lt;dsahern@gmail.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Namhyung Kim &lt;namhyung@gmail.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/r/1377522030-27870-3-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>
Record pid on struct thread.  The member is named 'pid_' to avoid
confusion with the 'tid' member which was previously named 'pid'.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Acked-by: David Ahern &lt;dsahern@gmail.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Namhyung Kim &lt;namhyung@gmail.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/r/1377522030-27870-3-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 tools: Sample after exit loses thread correlation</title>
<updated>2013-08-26T20:25:36+00:00</updated>
<author>
<name>David Ahern</name>
<email>dsahern@gmail.com</email>
</author>
<published>2013-08-14T14:49:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=236a3bbd5cb51edbf9550f5a7df885665d18a271'/>
<id>236a3bbd5cb51edbf9550f5a7df885665d18a271</id>
<content type='text'>
Occassionally events (e.g., context-switch, sched tracepoints) are losing
the conversion of sample data associated with a thread. For example:

$ perf record -e sched:sched_switch -c 1 -a -- sleep 5
$ perf script
&lt;selected events shown&gt;
    ls 30482 [000] 1379727.583037: sched:sched_switch: prev_comm=ls prev_pid=30482 ...
    ls 30482 [000] 1379727.586339: sched:sched_switch: prev_comm=ls prev_pid=30482 ...
:30482 30482 [000] 1379727.589462: sched:sched_switch: prev_comm=ls prev_pid=30482 ...

The last line lost the conversion from tid to comm. If you look at the events
(perf script -D) you see why - a SAMPLE event is generated after the EXIT:

0 1379727589449774 0x1540b0 [0x38]: PERF_RECORD_EXIT(30482:30482):(30482:30482)
0 1379727589462497 0x1540e8 [0x80]: PERF_RECORD_SAMPLE(IP, 1): 30482/30482: 0xffffffff816416f1 period: 1 addr: 0
... thread: :30482:30482

When perf processes the EXIT event the thread is moved to the dead_threads
list. When the SAMPLE event is processed no thread exists for the pid so a new
one is created by machine__findnew_thread.

This patch address the problem by delaying the move to the dead_threads list
until the tid is re-used (per Adrian's suggestion).

With this patch we get the previous example shows:

  ls 30482 [000] 1379727.583037: sched:sched_switch: prev_comm=ls prev_pid=30482 ...
  ls 30482 [000] 1379727.586339: sched:sched_switch: prev_comm=ls prev_pid=30482 ...
  ls 30482 [000] 1379727.589462: sched:sched_switch: prev_comm=ls prev_pid=30482 ...

and

  0 1379727589449774 0x1540b0 [0x38]: PERF_RECORD_EXIT(30482:30482):(30482:30482)
  0 1379727589462497 0x1540e8 [0x80]: PERF_RECORD_SAMPLE(IP, 1): 30482/30482: 0xffffffff816416f1 period: 1 addr: 0
  ... thread: ls:30482

v4: per Arnaldo's request add dead flag to thread struct and set when task exits

v3: re-do from a time based check to a delayed move to dead_threads list

v2: Rebased to latest perf/core branch. Changed time comparison to use
    a macro which explicitly shows the time basis

Signed-off-by: David Ahern &lt;dsahern@gmail.com&gt;
Acked-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&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: http://lkml.kernel.org/r/1376491767-84171-1-git-send-email-dsahern@gmail.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>
Occassionally events (e.g., context-switch, sched tracepoints) are losing
the conversion of sample data associated with a thread. For example:

$ perf record -e sched:sched_switch -c 1 -a -- sleep 5
$ perf script
&lt;selected events shown&gt;
    ls 30482 [000] 1379727.583037: sched:sched_switch: prev_comm=ls prev_pid=30482 ...
    ls 30482 [000] 1379727.586339: sched:sched_switch: prev_comm=ls prev_pid=30482 ...
:30482 30482 [000] 1379727.589462: sched:sched_switch: prev_comm=ls prev_pid=30482 ...

The last line lost the conversion from tid to comm. If you look at the events
(perf script -D) you see why - a SAMPLE event is generated after the EXIT:

0 1379727589449774 0x1540b0 [0x38]: PERF_RECORD_EXIT(30482:30482):(30482:30482)
0 1379727589462497 0x1540e8 [0x80]: PERF_RECORD_SAMPLE(IP, 1): 30482/30482: 0xffffffff816416f1 period: 1 addr: 0
... thread: :30482:30482

When perf processes the EXIT event the thread is moved to the dead_threads
list. When the SAMPLE event is processed no thread exists for the pid so a new
one is created by machine__findnew_thread.

This patch address the problem by delaying the move to the dead_threads list
until the tid is re-used (per Adrian's suggestion).

With this patch we get the previous example shows:

  ls 30482 [000] 1379727.583037: sched:sched_switch: prev_comm=ls prev_pid=30482 ...
  ls 30482 [000] 1379727.586339: sched:sched_switch: prev_comm=ls prev_pid=30482 ...
  ls 30482 [000] 1379727.589462: sched:sched_switch: prev_comm=ls prev_pid=30482 ...

and

  0 1379727589449774 0x1540b0 [0x38]: PERF_RECORD_EXIT(30482:30482):(30482:30482)
  0 1379727589462497 0x1540e8 [0x80]: PERF_RECORD_SAMPLE(IP, 1): 30482/30482: 0xffffffff816416f1 period: 1 addr: 0
  ... thread: ls:30482

v4: per Arnaldo's request add dead flag to thread struct and set when task exits

v3: re-do from a time based check to a delayed move to dead_threads list

v2: Rebased to latest perf/core branch. Changed time comparison to use
    a macro which explicitly shows the time basis

Signed-off-by: David Ahern &lt;dsahern@gmail.com&gt;
Acked-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&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: http://lkml.kernel.org/r/1376491767-84171-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Remove filter parameter of thread__find_addr_map()</title>
<updated>2013-08-12T13:31:12+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2013-08-08T11:32:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=326f59bf645ea6c99709c67d9712df46019fa7a8'/>
<id>326f59bf645ea6c99709c67d9712df46019fa7a8</id>
<content type='text'>
Now that the symbol filter is recorded on the machine there is no need
to pass it to thread__find_addr_map().  So remove it.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Namhyung Kim &lt;namhyung@gmail.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/r/1375961547-30267-9-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>
Now that the symbol filter is recorded on the machine there is no need
to pass it to thread__find_addr_map().  So remove it.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Namhyung Kim &lt;namhyung@gmail.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/r/1375961547-30267-9-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 tools: Remove filter parameter of thread__find_addr_location()</title>
<updated>2013-08-12T13:31:12+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2013-08-08T11:32:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=61710bdee324aab1c148c8573ee49cea59d05874'/>
<id>61710bdee324aab1c148c8573ee49cea59d05874</id>
<content type='text'>
Now that the symbol filter is recorded on the machine there is no need
to pass it to thread__find_addr_location().  So remove it.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Namhyung Kim &lt;namhyung@gmail.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/r/1375961547-30267-8-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>
Now that the symbol filter is recorded on the machine there is no need
to pass it to thread__find_addr_location().  So remove it.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Namhyung Kim &lt;namhyung@gmail.com&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Link: http://lkml.kernel.org/r/1375961547-30267-8-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
