<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/tools, branch linux-4.1.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 tests: Decompress kernel module before objdump</title>
<updated>2018-05-23T01:36:28+00:00</updated>
<author>
<name>Namhyung Kim</name>
<email>namhyung@kernel.org</email>
</author>
<published>2017-06-08T07:31:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=955b7048c0878f13cd8606fa9c1ba7ff29710b6b'/>
<id>955b7048c0878f13cd8606fa9c1ba7ff29710b6b</id>
<content type='text'>
[ Upstream commit 94df1040b1e6aacd8dec0ba3c61d7e77cd695f26 ]

If a kernel modules is compressed, it should be decompressed before
running objdump to parse binary data correctly.  This fixes a failure of
object code reading test for me.

Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Acked-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170608073109.30699-8-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 94df1040b1e6aacd8dec0ba3c61d7e77cd695f26 ]

If a kernel modules is compressed, it should be decompressed before
running objdump to parse binary data correctly.  This fixes a failure of
object code reading test for me.

Signed-off-by: Namhyung Kim &lt;namhyung@kernel.org&gt;
Acked-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20170608073109.30699-8-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf report: Ensure the perf DSO mapping matches what libdw sees</title>
<updated>2018-05-23T01:36:28+00:00</updated>
<author>
<name>Milian Wolff</name>
<email>milian.wolff@kdab.com</email>
</author>
<published>2017-06-02T14:37:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0af3eee08b7c9d4aaea2a35cdc32f66b9761e36d'/>
<id>0af3eee08b7c9d4aaea2a35cdc32f66b9761e36d</id>
<content type='text'>
[ Upstream commit 2538b9e2450ae255337c04356e9e0f8cb9ec48d9 ]

In some situations the libdw unwinder stopped working properly.  I.e.
with libunwind we see:

~~~~~
heaptrack_gui  2228 135073.400112:     641314 cycles:
	            e8ed _dl_fixup (/usr/lib/ld-2.25.so)
	           15f06 _dl_runtime_resolve_sse_vex (/usr/lib/ld-2.25.so)
	           ed94c KDynamicJobTracker::KDynamicJobTracker (/home/milian/projects/compiled/kf5/lib64/libKF5KIOWidgets.so.5.35.0)
	           608f3 _GLOBAL__sub_I_kdynamicjobtracker.cpp (/home/milian/projects/compiled/kf5/lib64/libKF5KIOWidgets.so.5.35.0)
	            f199 call_init.part.0 (/usr/lib/ld-2.25.so)
	            f2a5 _dl_init (/usr/lib/ld-2.25.so)
	             db9 _dl_start_user (/usr/lib/ld-2.25.so)
~~~~~

But with libdw and without this patch this sample is not properly
unwound:

~~~~~
heaptrack_gui  2228 135073.400112:     641314 cycles:
	            e8ed _dl_fixup (/usr/lib/ld-2.25.so)
	           15f06 _dl_runtime_resolve_sse_vex (/usr/lib/ld-2.25.so)
	           ed94c KDynamicJobTracker::KDynamicJobTracker (/home/milian/projects/compiled/kf5/lib64/libKF5KIOWidgets.so.5.35.0)
~~~~~

Debug output showed me that libdw found a module for the last frame
address, but it thinks it belongs to /usr/lib/ld-2.25.so. This patch
double-checks what libdw sees and what perf knows. If the mappings
mismatch, we now report the elf known to perf. This fixes the situation
above, and the libdw unwinder produces the same stack as libunwind.

Signed-off-by: Milian Wolff &lt;milian.wolff@kdab.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: http://lkml.kernel.org/r/20170602143753.16907-1-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 2538b9e2450ae255337c04356e9e0f8cb9ec48d9 ]

In some situations the libdw unwinder stopped working properly.  I.e.
with libunwind we see:

~~~~~
heaptrack_gui  2228 135073.400112:     641314 cycles:
	            e8ed _dl_fixup (/usr/lib/ld-2.25.so)
	           15f06 _dl_runtime_resolve_sse_vex (/usr/lib/ld-2.25.so)
	           ed94c KDynamicJobTracker::KDynamicJobTracker (/home/milian/projects/compiled/kf5/lib64/libKF5KIOWidgets.so.5.35.0)
	           608f3 _GLOBAL__sub_I_kdynamicjobtracker.cpp (/home/milian/projects/compiled/kf5/lib64/libKF5KIOWidgets.so.5.35.0)
	            f199 call_init.part.0 (/usr/lib/ld-2.25.so)
	            f2a5 _dl_init (/usr/lib/ld-2.25.so)
	             db9 _dl_start_user (/usr/lib/ld-2.25.so)
~~~~~

But with libdw and without this patch this sample is not properly
unwound:

~~~~~
heaptrack_gui  2228 135073.400112:     641314 cycles:
	            e8ed _dl_fixup (/usr/lib/ld-2.25.so)
	           15f06 _dl_runtime_resolve_sse_vex (/usr/lib/ld-2.25.so)
	           ed94c KDynamicJobTracker::KDynamicJobTracker (/home/milian/projects/compiled/kf5/lib64/libKF5KIOWidgets.so.5.35.0)
~~~~~

Debug output showed me that libdw found a module for the last frame
address, but it thinks it belongs to /usr/lib/ld-2.25.so. This patch
double-checks what libdw sees and what perf knows. If the mappings
mismatch, we now report the elf known to perf. This fixes the situation
above, and the libdw unwinder produces the same stack as libunwind.

Signed-off-by: Milian Wolff &lt;milian.wolff@kdab.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: http://lkml.kernel.org/r/20170602143753.16907-1-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf trace: Add mmap alias for s390</title>
<updated>2018-05-23T01:36:27+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2017-05-31T11:35:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f9d6c87a047e53477ac2cf3975b639e49287115d'/>
<id>f9d6c87a047e53477ac2cf3975b639e49287115d</id>
<content type='text'>
[ Upstream commit 54265664c15a68905d8d67d19205e9a767636434 ]

The s390 architecture maps sys_mmap (nr 90) into sys_old_mmap.  For this
reason perf trace can't find the proper syscall event to get args format
from and displays it wrongly as 'continued'.

To fix that fill the "alias" field with "old_mmap" for trace's mmap record
to get the correct translation.

Before:
     0.042 ( 0.011 ms): vest/43052 fstat(statbuf: 0x3ffff89fd90                ) = 0
     0.042 ( 0.028 ms): vest/43052  ... [continued]: mmap()) = 0x3fffd6e2000
     0.072 ( 0.025 ms): vest/43052 read(buf: 0x3fffd6e2000, count: 4096        ) = 6

After:
     0.045 ( 0.011 ms): fstat(statbuf: 0x3ffff8a0930                           ) = 0
     0.057 ( 0.018 ms): mmap(arg: 0x3ffff8a0858                                ) = 0x3fffd14a000
     0.076 ( 0.025 ms): read(buf: 0x3fffd14a000, count: 4096                   ) = 6

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/20170531113557.19175-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 54265664c15a68905d8d67d19205e9a767636434 ]

The s390 architecture maps sys_mmap (nr 90) into sys_old_mmap.  For this
reason perf trace can't find the proper syscall event to get args format
from and displays it wrongly as 'continued'.

To fix that fill the "alias" field with "old_mmap" for trace's mmap record
to get the correct translation.

Before:
     0.042 ( 0.011 ms): vest/43052 fstat(statbuf: 0x3ffff89fd90                ) = 0
     0.042 ( 0.028 ms): vest/43052  ... [continued]: mmap()) = 0x3fffd6e2000
     0.072 ( 0.025 ms): vest/43052 read(buf: 0x3fffd6e2000, count: 4096        ) = 6

After:
     0.045 ( 0.011 ms): fstat(statbuf: 0x3ffff8a0930                           ) = 0
     0.057 ( 0.018 ms): mmap(arg: 0x3ffff8a0858                                ) = 0x3fffd14a000
     0.076 ( 0.025 ms): read(buf: 0x3fffd14a000, count: 4096                   ) = 6

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/20170531113557.19175-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>selftests/powerpc: Fix TM resched DSCR test with some compilers</title>
<updated>2018-05-23T01:36:25+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2017-05-19T01:29:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6100ae38e37c27b75d6c6a8ed4cf9f501eba94af'/>
<id>6100ae38e37c27b75d6c6a8ed4cf9f501eba94af</id>
<content type='text'>
[ Upstream commit fe06fe860250a4f01d0eaf70a2563b1997174a74 ]

The tm-resched-dscr test has started failing sometimes, depending on
what compiler it's built with, eg:

  test: tm_resched_dscr
  Check DSCR TM context switch: tm-resched-dscr: tm-resched-dscr.c:76: test_body: Assertion `rv' failed.
  !! child died by signal 6

When it fails we see that the compiler doesn't initialise rv to 1 before
entering the inline asm block. Although that's counter intuitive, it
is allowed because we tell the compiler that the inline asm will write
to rv (using "=r"), meaning the original value is irrelevant.

Marking it as a read/write parameter would presumably work, but it seems
simpler to fix it by setting the initial value of rv in the inline asm.

Fixes: 96d016108640 ("powerpc: Correct DSCR during TM context switch")
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Acked-by: Michael Neuling &lt;mikey@neuling.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit fe06fe860250a4f01d0eaf70a2563b1997174a74 ]

The tm-resched-dscr test has started failing sometimes, depending on
what compiler it's built with, eg:

  test: tm_resched_dscr
  Check DSCR TM context switch: tm-resched-dscr: tm-resched-dscr.c:76: test_body: Assertion `rv' failed.
  !! child died by signal 6

When it fails we see that the compiler doesn't initialise rv to 1 before
entering the inline asm block. Although that's counter intuitive, it
is allowed because we tell the compiler that the inline asm will write
to rv (using "=r"), meaning the original value is irrelevant.

Marking it as a read/write parameter would presumably work, but it seems
simpler to fix it by setting the initial value of rv in the inline asm.

Fixes: 96d016108640 ("powerpc: Correct DSCR during TM context switch")
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Acked-by: Michael Neuling &lt;mikey@neuling.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rcutorture/configinit: Fix build directory error message</title>
<updated>2018-05-23T01:33:47+00:00</updated>
<author>
<name>SeongJae Park</name>
<email>sj38.park@gmail.com</email>
</author>
<published>2017-11-03T10:17:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1cbc92464538feb57597a1909a998bb9b17faa78'/>
<id>1cbc92464538feb57597a1909a998bb9b17faa78</id>
<content type='text'>
[ Upstream commit 2adfa4210f8f35cdfb4e08318cc06b99752964c2 ]

The 'configinit.sh' script checks the format of optional argument for the
build directory, printing an error message if the format is not valid.
However, the error message uses the wrong variable, indicating an empty
string even though the user entered a non-empty (but erroneous) string.
This commit fixes the script to use the correct variable.

Fixes: c87b9c601ac8 ("rcutorture: Add KVM-based test framework")

Signed-off-by: SeongJae Park &lt;sj38.park@gmail.com&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 2adfa4210f8f35cdfb4e08318cc06b99752964c2 ]

The 'configinit.sh' script checks the format of optional argument for the
build directory, printing an error message if the format is not valid.
However, the error message uses the wrong variable, indicating an empty
string even though the user entered a non-empty (but erroneous) string.
This commit fixes the script to use the correct variable.

Fixes: c87b9c601ac8 ("rcutorture: Add KVM-based test framework")

Signed-off-by: SeongJae Park &lt;sj38.park@gmail.com&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools/usbip: fixes build with musl libc toolchain</title>
<updated>2018-05-23T01:33:46+00:00</updated>
<author>
<name>Julien BOIBESSOT</name>
<email>julien.boibessot@armadeus.com</email>
</author>
<published>2017-12-05T17:48:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=854ae7b427c6bcf0b45824ce464458c067dcd606'/>
<id>854ae7b427c6bcf0b45824ce464458c067dcd606</id>
<content type='text'>
[ Upstream commit 77be4c878c72e411ad22af96b6f81dd45c26450a ]

Indeed musl doesn't define old SIGCLD signal name but only new one SIGCHLD.
SIGCHLD is the new POSIX name for that signal so it doesn't change
anything on other libcs.

This fixes this kind of build error:

usbipd.c: In function ‘set_signal’:
usbipd.c:459:12: error: 'SIGCLD' undeclared (first use in this function)
  sigaction(SIGCLD, &amp;act, NULL);
            ^~~~~~
usbipd.c:459:12: note: each undeclared identifier is reported only once
	for each function it appears in
Makefile:407: recipe for target 'usbipd.o' failed
make[3]: *** [usbipd.o] Error 1

Signed-off-by: Julien BOIBESSOT &lt;julien.boibessot@armadeus.com&gt;
Acked-by: Shuah Khan &lt;shuahkh@osg.samsung.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 77be4c878c72e411ad22af96b6f81dd45c26450a ]

Indeed musl doesn't define old SIGCLD signal name but only new one SIGCHLD.
SIGCHLD is the new POSIX name for that signal so it doesn't change
anything on other libcs.

This fixes this kind of build error:

usbipd.c: In function ‘set_signal’:
usbipd.c:459:12: error: 'SIGCLD' undeclared (first use in this function)
  sigaction(SIGCLD, &amp;act, NULL);
            ^~~~~~
usbipd.c:459:12: note: each undeclared identifier is reported only once
	for each function it appears in
Makefile:407: recipe for target 'usbipd.o' failed
make[3]: *** [usbipd.o] Error 1

Signed-off-by: Julien BOIBESSOT &lt;julien.boibessot@armadeus.com&gt;
Acked-by: Shuah Khan &lt;shuahkh@osg.samsung.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf session: Don't rely on evlist in pipe mode</title>
<updated>2018-05-23T01:33:45+00:00</updated>
<author>
<name>David Carrillo-Cisneros</name>
<email>davidcc@google.com</email>
</author>
<published>2017-04-10T20:14:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=32dfafdd93b24b74cb288ef10da482ed30231109'/>
<id>32dfafdd93b24b74cb288ef10da482ed30231109</id>
<content type='text'>
[ Upstream commit 0973ad97c187e06aece61f685b9c3b2d93290a73 ]

Session sets a number parameters that rely on evlist. These parameters
are not used in pipe-mode and should not be set, since evlist is
unavailable. Fix that.

Signed-off-by: David Carrillo-Cisneros &lt;davidcc@google.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: He Kuang &lt;hekuang@huawei.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Paul Turner &lt;pjt@google.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Simon Que &lt;sque@chromium.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/20170410201432.24807-6-davidcc@google.com
[ Check if file != NULL in perf_session__new(), like when used by builtin-top.c ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 0973ad97c187e06aece61f685b9c3b2d93290a73 ]

Session sets a number parameters that rely on evlist. These parameters
are not used in pipe-mode and should not be set, since evlist is
unavailable. Fix that.

Signed-off-by: David Carrillo-Cisneros &lt;davidcc@google.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: He Kuang &lt;hekuang@huawei.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Paul Turner &lt;pjt@google.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Simon Que &lt;sque@chromium.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/20170410201432.24807-6-davidcc@google.com
[ Check if file != NULL in perf_session__new(), like when used by builtin-top.c ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf inject: Copy events when reordering events in pipe mode</title>
<updated>2018-05-23T01:33:45+00:00</updated>
<author>
<name>David Carrillo-Cisneros</name>
<email>davidcc@google.com</email>
</author>
<published>2017-04-10T20:14:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c802947ae26d79b07e930891e2c06af521124a00'/>
<id>c802947ae26d79b07e930891e2c06af521124a00</id>
<content type='text'>
[ Upstream commit 1e0d4f0200e4dbdfc38d818f329d8a0955f7c6f5 ]

__perf_session__process_pipe_events reuses the same memory buffer to
process all events in the pipe.

When reordering is needed (e.g. -b option), events are not immediately
flushed, but kept around until reordering is possible, causing
memory corruption.

The problem is usually observed by a "Unknown sample error" output. It
can easily be reproduced by:

  perf record -o - noploop | perf inject -b &gt; output

Committer testing:

Before:

  $ perf record -o - stress -t 2 -c 2 | perf inject -b &gt; /dev/null
  stress: info: [8297] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
  stress: info: [8297] successful run completed in 2s
  [ perf record: Woken up 3 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  Warning:
  Found 1 unknown events!

  Is this an older tool processing a perf.data file generated by a more recent tool?

  If that is not the case, consider reporting to linux-kernel@vger.kernel.org.

  $

After:

  $ perf record -o - stress -t 2 -c 2 | perf inject -b &gt; /dev/null
  stress: info: [9027] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
  stress: info: [9027] successful run completed in 2s
  [ perf record: Woken up 3 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  no symbols found in /usr/bin/stress, maybe install a debug package?
  no symbols found in /usr/bin/stress, maybe install a debug package?
  $

Signed-off-by: David Carrillo-Cisneros &lt;davidcc@google.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: He Kuang &lt;hekuang@huawei.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Paul Turner &lt;pjt@google.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Simon Que &lt;sque@chromium.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/20170410201432.24807-3-davidcc@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 1e0d4f0200e4dbdfc38d818f329d8a0955f7c6f5 ]

__perf_session__process_pipe_events reuses the same memory buffer to
process all events in the pipe.

When reordering is needed (e.g. -b option), events are not immediately
flushed, but kept around until reordering is possible, causing
memory corruption.

The problem is usually observed by a "Unknown sample error" output. It
can easily be reproduced by:

  perf record -o - noploop | perf inject -b &gt; output

Committer testing:

Before:

  $ perf record -o - stress -t 2 -c 2 | perf inject -b &gt; /dev/null
  stress: info: [8297] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
  stress: info: [8297] successful run completed in 2s
  [ perf record: Woken up 3 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  Warning:
  Found 1 unknown events!

  Is this an older tool processing a perf.data file generated by a more recent tool?

  If that is not the case, consider reporting to linux-kernel@vger.kernel.org.

  $

After:

  $ perf record -o - stress -t 2 -c 2 | perf inject -b &gt; /dev/null
  stress: info: [9027] dispatching hogs: 2 cpu, 0 io, 0 vm, 0 hdd
  stress: info: [9027] successful run completed in 2s
  [ perf record: Woken up 3 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  no symbols found in /usr/bin/stress, maybe install a debug package?
  no symbols found in /usr/bin/stress, maybe install a debug package?
  $

Signed-off-by: David Carrillo-Cisneros &lt;davidcc@google.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Andi Kleen &lt;ak@linux.intel.com&gt;
Cc: He Kuang &lt;hekuang@huawei.com&gt;
Cc: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Cc: Paul Turner &lt;pjt@google.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Simon Que &lt;sque@chromium.org&gt;
Cc: Stephane Eranian &lt;eranian@google.com&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/20170410201432.24807-3-davidcc@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tools: Make perf_event__synthesize_mmap_events() scale</title>
<updated>2018-05-23T01:33:43+00:00</updated>
<author>
<name>Stephane Eranian</name>
<email>eranian@google.com</email>
</author>
<published>2017-03-15T17:17:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2e0f2cce806995a084dba072a1d6778d4b32e29a'/>
<id>2e0f2cce806995a084dba072a1d6778d4b32e29a</id>
<content type='text'>
[ Upstream commit 88b897a30c525c2eee6e7f16e1e8d0f18830845e ]

This patch significantly improves the execution time of
perf_event__synthesize_mmap_events() when running perf record on systems
where processes have lots of threads.

It just happens that cat /proc/pid/maps support uses a O(N^2) algorithm to
generate each map line in the maps file.  If you have 1000 threads, then you
have necessarily 1000 stacks.  For each vma, you need to check if it
corresponds to a thread's stack.  With a large number of threads, this can take
a very long time. I have seen latencies &gt;&gt; 10mn.

As of today, perf does not use the fact that a mapping is a stack, therefore we
can work around the issue by using /proc/pid/tasks/pid/maps.  This entry does
not try to map a vma to stack and is thus much faster with no loss of
functonality.

The proc-map-timeout logic is kept in case users still want some upper limit.

In V2, we fix the file path from /proc/pid/tasks/pid/maps to actual
/proc/pid/task/pid/maps, tasks -&gt; task.  Thanks Arnaldo for catching this.

Committer note:

This problem seems to have been elliminated in the kernel since commit :
b18cb64ead40 ("fs/proc: Stop trying to report thread stacks").

Signed-off-by: Stephane Eranian &lt;eranian@google.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/20170315135059.GC2177@redhat.com
Link: http://lkml.kernel.org/r/1489598233-25586-1-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 88b897a30c525c2eee6e7f16e1e8d0f18830845e ]

This patch significantly improves the execution time of
perf_event__synthesize_mmap_events() when running perf record on systems
where processes have lots of threads.

It just happens that cat /proc/pid/maps support uses a O(N^2) algorithm to
generate each map line in the maps file.  If you have 1000 threads, then you
have necessarily 1000 stacks.  For each vma, you need to check if it
corresponds to a thread's stack.  With a large number of threads, this can take
a very long time. I have seen latencies &gt;&gt; 10mn.

As of today, perf does not use the fact that a mapping is a stack, therefore we
can work around the issue by using /proc/pid/tasks/pid/maps.  This entry does
not try to map a vma to stack and is thus much faster with no loss of
functonality.

The proc-map-timeout logic is kept in case users still want some upper limit.

In V2, we fix the file path from /proc/pid/tasks/pid/maps to actual
/proc/pid/task/pid/maps, tasks -&gt; task.  Thanks Arnaldo for catching this.

Committer note:

This problem seems to have been elliminated in the kernel since commit :
b18cb64ead40 ("fs/proc: Stop trying to report thread stacks").

Signed-off-by: Stephane Eranian &lt;eranian@google.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Link: http://lkml.kernel.org/r/20170315135059.GC2177@redhat.com
Link: http://lkml.kernel.org/r/1489598233-25586-1-git-send-email-eranian@google.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf bench numa: Fixup discontiguous/sparse numa nodes</title>
<updated>2018-03-04T15:28:25+00:00</updated>
<author>
<name>Satheesh Rajendran</name>
<email>sathnaga@linux.vnet.ibm.com</email>
</author>
<published>2017-11-22T16:43:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c48a86aad89e9565596574d5c557974162e5f146'/>
<id>c48a86aad89e9565596574d5c557974162e5f146</id>
<content type='text'>
[ Upstream commit 321a7c35c90cc834851ceda18a8ee18f1d032b92 ]

Certain systems are designed to have sparse/discontiguous nodes.  On
such systems, 'perf bench numa' hangs, shows wrong number of nodes and
shows values for non-existent nodes. Handle this by only taking nodes
that are exposed by kernel to userspace.

Signed-off-by: Satheesh Rajendran &lt;sathnaga@linux.vnet.ibm.com&gt;
Reviewed-by: Srikar Dronamraju &lt;srikar@linux.vnet.ibm.com&gt;
Acked-by: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Link: http://lkml.kernel.org/r/1edbcd353c009e109e93d78f2f46381930c340fe.1511368645.git.sathnaga@linux.vnet.ibm.com
Signed-off-by: Balamuruhan S &lt;bala24@linux.vnet.ibm.com&gt;
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 321a7c35c90cc834851ceda18a8ee18f1d032b92 ]

Certain systems are designed to have sparse/discontiguous nodes.  On
such systems, 'perf bench numa' hangs, shows wrong number of nodes and
shows values for non-existent nodes. Handle this by only taking nodes
that are exposed by kernel to userspace.

Signed-off-by: Satheesh Rajendran &lt;sathnaga@linux.vnet.ibm.com&gt;
Reviewed-by: Srikar Dronamraju &lt;srikar@linux.vnet.ibm.com&gt;
Acked-by: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Link: http://lkml.kernel.org/r/1edbcd353c009e109e93d78f2f46381930c340fe.1511368645.git.sathnaga@linux.vnet.ibm.com
Signed-off-by: Balamuruhan S &lt;bala24@linux.vnet.ibm.com&gt;
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@microsoft.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
