<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/tools/perf/tests, branch v4.18-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>perf test record+probe_libc_inet_pton: Ask 'nm' for dynamic symbols</title>
<updated>2018-06-06T15:52:06+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2018-06-04T14:11:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=005cc008bc188f81f0c1ae53dafb50cdb6df19c2'/>
<id>005cc008bc188f81f0c1ae53dafb50cdb6df19c2</id>
<content type='text'>
Adrian reported that this test fails in his system where:

  probe libc's inet_pton &amp; backtrace it with ping: FAILED!
  root@kbl04:~/git/linux-perf# nm -g /lib/x86_64-linux-gnu/libc-2.19.so | grep inet_pton
  nm: /lib/x86_64-linux-gnu/libc-2.19.so: no symbols

This fails on ubuntu systems, with Adrian's being kubuntu 14.04, I
tested with ubuntu 14.04.4 and 18.04, and there we need to use the
-D/--dynamic 'nm' option to have this test working. And it works as well
with that on fedora 27, so use it.

Reported-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Hendrik Brueckner &lt;brueckner@linux.vnet.ibm.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Cc: Sandipan Das &lt;sandipan@linux.vnet.ibm.com&gt;
Cc: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: https://lkml.kernel.org/n/tip-zlfnbauad3ljlmtjgo0v660u@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>
Adrian reported that this test fails in his system where:

  probe libc's inet_pton &amp; backtrace it with ping: FAILED!
  root@kbl04:~/git/linux-perf# nm -g /lib/x86_64-linux-gnu/libc-2.19.so | grep inet_pton
  nm: /lib/x86_64-linux-gnu/libc-2.19.so: no symbols

This fails on ubuntu systems, with Adrian's being kubuntu 14.04, I
tested with ubuntu 14.04.4 and 18.04, and there we need to use the
-D/--dynamic 'nm' option to have this test working. And it works as well
with that on fedora 27, so use it.

Reported-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: David Ahern &lt;dsahern@gmail.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Hendrik Brueckner &lt;brueckner@linux.vnet.ibm.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Cc: Sandipan Das &lt;sandipan@linux.vnet.ibm.com&gt;
Cc: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: https://lkml.kernel.org/n/tip-zlfnbauad3ljlmtjgo0v660u@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf test code-reading: Fix perf_env setup for PTI entry trampolines</title>
<updated>2018-06-06T15:52:05+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2018-06-05T07:30:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=f6c66d73bb8192d357bb5fb8cd5826920f811d8c'/>
<id>f6c66d73bb8192d357bb5fb8cd5826920f811d8c</id>
<content type='text'>
The "Object code reading" test will not create maps for the PTI entry
trampolines unless the machine environment exists to show that the arch is
x86_64.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Reported-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Link: http://lkml.kernel.org/r/1528183800-21577-1-git-send-email-adrian.hunter@intel.com
[ split from a larger patch ]
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 "Object code reading" test will not create maps for the PTI entry
trampolines unless the machine environment exists to show that the arch is
x86_64.

Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Reported-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Link: http://lkml.kernel.org/r/1528183800-21577-1-git-send-email-adrian.hunter@intel.com
[ split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf tests kmod-path: Add tests for vdso32 and vdsox32</title>
<updated>2018-06-06T15:52:03+00:00</updated>
<author>
<name>Adrian Hunter</name>
<email>adrian.hunter@intel.com</email>
</author>
<published>2018-06-04T12:56:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=dcaeae4e2c266452e04dc3d83b10469be9fe419e'/>
<id>dcaeae4e2c266452e04dc3d83b10469be9fe419e</id>
<content type='text'>
Add tests for vdso32 and vdsox32. This will cause the overall test to
fail because __kmod_path__parse() does not handle vdso32 or vdsox32.

Fixes: 1f121b03d058 ("perf tools: Deal with kernel module names in '[]' correctly")
Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1528117014-30032-2-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>
Add tests for vdso32 and vdsox32. This will cause the overall test to
fail because __kmod_path__parse() does not handle vdso32 or vdsox32.

Fixes: 1f121b03d058 ("perf tools: Deal with kernel module names in '[]' correctly")
Signed-off-by: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Wang Nan &lt;wangnan0@huawei.com&gt;
Link: http://lkml.kernel.org/r/1528117014-30032-2-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 evsel: Add has_callchain() helper to make code more compact/clear</title>
<updated>2018-06-05T13:09:54+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2018-05-28T19:00:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=27de9b2bd996de0ca4079c42c81c85158e10145c'/>
<id>27de9b2bd996de0ca4079c42c81c85158e10145c</id>
<content type='text'>
Its common to have the (evsel-&gt;attr.sample_type &amp; PERF_SAMPLE_CALLCHAIN),
so add an evsel__has_callchain(evsel) helper.

This will actually get more uses as we check that instead of
symbol_conf.use_callchain in places where that produces the same result
but makes this decision to be more fine grained, per evsel.

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-145340oytbthatpfeaq1do18@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>
Its common to have the (evsel-&gt;attr.sample_type &amp; PERF_SAMPLE_CALLCHAIN),
so add an evsel__has_callchain(evsel) helper.

This will actually get more uses as we check that instead of
symbol_conf.use_callchain in places where that produces the same result
but makes this decision to be more fine grained, per evsel.

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-145340oytbthatpfeaq1do18@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf test: Use header file util/debug.h</title>
<updated>2018-06-04T13:28:53+00:00</updated>
<author>
<name>Thomas Richter</name>
<email>tmricht@linux.ibm.com</email>
</author>
<published>2018-05-28T13:48:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e9ee0dce45e522221c18b2f24621a0d00d0bff40'/>
<id>e9ee0dce45e522221c18b2f24621a0d00d0bff40</id>
<content type='text'>
Use the header file util/debug.h instead of declaration of verbose
variable.

Signed-off-by: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Hendrik Brueckner &lt;brueckner@linux.vnet.ibm.com&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Link: http://lkml.kernel.org/r/20180528134817.36643-1-tmricht@linux.ibm.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>
Use the header file util/debug.h instead of declaration of verbose
variable.

Signed-off-by: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Hendrik Brueckner &lt;brueckner@linux.vnet.ibm.com&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Link: http://lkml.kernel.org/r/20180528134817.36643-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge remote-tracking branch 'tip/perf/urgent' into perf/core</title>
<updated>2018-06-04T13:28:20+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2018-06-04T13:28:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7869e5889477e4e32e4024d665431b35e8b7b693'/>
<id>7869e5889477e4e32e4024d665431b35e8b7b693</id>
<content type='text'>
To pick up fixes.

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 pick up fixes.

Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf test: "Session topology" dumps core on s390</title>
<updated>2018-05-30T14:43:58+00:00</updated>
<author>
<name>Thomas Richter</name>
<email>tmricht@linux.ibm.com</email>
</author>
<published>2018-05-28T07:36:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d121109100bda84bbbb199dab97f9d56432ab235'/>
<id>d121109100bda84bbbb199dab97f9d56432ab235</id>
<content type='text'>
The "perf test Session topology" entry fails with core dump on s390. The root
cause is a NULL pointer dereference in function check_cpu_topology() line 76
(or line 82 without -v).

The session-&gt;header.env.cpu variable is NULL because on s390 function
process_cpu_topology() returns with error:

    socket_id number is too big.
    You may need to upgrade the perf tool.

and releases the env.cpu variable via zfree() and sets it to NULL.

Here is the gdb output:
(gdb) n
76                      pr_debug("CPU %d, core %d, socket %d\n", i,
(gdb) n

Program received signal SIGSEGV, Segmentation fault.
0x00000000010f4d9e in check_cpu_topology (path=0x3ffffffd6c8
	"/tmp/perf-test-J6CHMa", map=0x14a1740) at tests/topology.c:76
76  pr_debug("CPU %d, core %d, socket %d\n", i,
(gdb)

Make sure the env.cpu variable is not used when its NULL.
Test for NULL pointer and return TEST_SKIP if so.

Output before:

  [root@p23lp27 perf]# ./perf test -F 39
  39: Session topology  :Segmentation fault (core dumped)
  [root@p23lp27 perf]#

Output after:

  [root@p23lp27 perf]# ./perf test -vF 39
  39: Session topology                                      :
  --- start ---
  templ file: /tmp/perf-test-Ajx59D
  socket_id number is too big.You may need to upgrade the perf tool.
  ---- end ----
  Session topology: Skip
  [root@p23lp27 perf]#

Signed-off-by: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Hendrik Brueckner &lt;brueckner@linux.vnet.ibm.com&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Link: http://lkml.kernel.org/r/20180528073657.11743-1-tmricht@linux.ibm.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 "perf test Session topology" entry fails with core dump on s390. The root
cause is a NULL pointer dereference in function check_cpu_topology() line 76
(or line 82 without -v).

The session-&gt;header.env.cpu variable is NULL because on s390 function
process_cpu_topology() returns with error:

    socket_id number is too big.
    You may need to upgrade the perf tool.

and releases the env.cpu variable via zfree() and sets it to NULL.

Here is the gdb output:
(gdb) n
76                      pr_debug("CPU %d, core %d, socket %d\n", i,
(gdb) n

Program received signal SIGSEGV, Segmentation fault.
0x00000000010f4d9e in check_cpu_topology (path=0x3ffffffd6c8
	"/tmp/perf-test-J6CHMa", map=0x14a1740) at tests/topology.c:76
76  pr_debug("CPU %d, core %d, socket %d\n", i,
(gdb)

Make sure the env.cpu variable is not used when its NULL.
Test for NULL pointer and return TEST_SKIP if so.

Output before:

  [root@p23lp27 perf]# ./perf test -F 39
  39: Session topology  :Segmentation fault (core dumped)
  [root@p23lp27 perf]#

Output after:

  [root@p23lp27 perf]# ./perf test -vF 39
  39: Session topology                                      :
  --- start ---
  templ file: /tmp/perf-test-Ajx59D
  socket_id number is too big.You may need to upgrade the perf tool.
  ---- end ----
  Session topology: Skip
  [root@p23lp27 perf]#

Signed-off-by: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Hendrik Brueckner &lt;brueckner@linux.vnet.ibm.com&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Link: http://lkml.kernel.org/r/20180528073657.11743-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf script: Show symbol offsets by default</title>
<updated>2018-05-18T19:31:40+00:00</updated>
<author>
<name>Sandipan Das</name>
<email>sandipan@linux.vnet.ibm.com</email>
</author>
<published>2018-05-17T06:33:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7903a70867230d9edbd5e886cd8b8a2b248f418f'/>
<id>7903a70867230d9edbd5e886cd8b8a2b248f418f</id>
<content type='text'>
Since the ip shown for a symbol is now always a virtual address, it
becomes difficult to correlate this with objdump output and determine
the exact instruction address. So, we always show the offset from the
start of the symbol.

This can be verified on a powerpc64le system running Fedora 27 as
follows:

  # perf probe -a sys_write
  # perf record -e probe:sys_write -g ~/test

Before applying this patch:

  # perf script

  test  9710 [013] 95614.332431: probe:sys_write: (c0000000004025b0)
          c0000000004025b0 sys_write (/lib/modules/4.17.0-rc4+/build/vmlinux)
          c00000000000b9e0 system_call (/lib/modules/4.17.0-rc4+/build/vmlinux)
              7fffb70d8234 __GI___libc_write (/usr/lib64/libc-2.26.so)
              7fffb7052c74 _IO_file_write@@GLIBC_2.17 (/usr/lib64/libc-2.26.so)
                  5afc1818 [unknown] ([unknown])
              7fffb7051a60 new_do_write (/usr/lib64/libc-2.26.so)
              7fffb7054638 _IO_do_write@@GLIBC_2.17 (/usr/lib64/libc-2.26.so)
              7fffb7054bbc _IO_file_overflow@@GLIBC_2.17 (/usr/lib64/libc-2.26.so)
              7fffb7055a24 __overflow (/usr/lib64/libc-2.26.so)
              7fffb7044548 _IO_puts (/usr/lib64/libc-2.26.so)
                  10000440 main (/home/sandipan/test)
              7fffb6fe36a0 generic_start_main.isra.0 (/usr/lib64/libc-2.26.so)
              7fffb6fe3898 __libc_start_main (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])
  ...

After applying this patch:

  # perf script

  test  9710 [013] 95614.332431: probe:sys_write: (c0000000004025b0)
          c0000000004025b0 sys_write+0x10 (/lib/modules/4.17.0-rc4+/build/vmlinux)
          c00000000000b9e0 system_call+0x58 (/lib/modules/4.17.0-rc4+/build/vmlinux)
              7fffb70d8234 __GI___libc_write+0x24 (/usr/lib64/libc-2.26.so)
              7fffb7052c74 _IO_file_write@@GLIBC_2.17+0x44 (/usr/lib64/libc-2.26.so)
                  5afc1818 [unknown] ([unknown])
              7fffb7051a60 new_do_write+0x90 (/usr/lib64/libc-2.26.so)
              7fffb7054638 _IO_do_write@@GLIBC_2.17+0x38 (/usr/lib64/libc-2.26.so)
              7fffb7054bbc _IO_file_overflow@@GLIBC_2.17+0x14c (/usr/lib64/libc-2.26.so)
              7fffb7055a24 __overflow+0x64 (/usr/lib64/libc-2.26.so)
              7fffb7044548 _IO_puts+0x218 (/usr/lib64/libc-2.26.so)
                  10000440 main+0x20 (/home/sandipan/test)
              7fffb6fe36a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
              7fffb6fe3898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])
  ...

Signed-off-by: Sandipan Das &lt;sandipan@linux.vnet.ibm.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Link: http://lkml.kernel.org/r/20180517063326.6319-2-sandipan@linux.vnet.ibm.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>
Since the ip shown for a symbol is now always a virtual address, it
becomes difficult to correlate this with objdump output and determine
the exact instruction address. So, we always show the offset from the
start of the symbol.

This can be verified on a powerpc64le system running Fedora 27 as
follows:

  # perf probe -a sys_write
  # perf record -e probe:sys_write -g ~/test

Before applying this patch:

  # perf script

  test  9710 [013] 95614.332431: probe:sys_write: (c0000000004025b0)
          c0000000004025b0 sys_write (/lib/modules/4.17.0-rc4+/build/vmlinux)
          c00000000000b9e0 system_call (/lib/modules/4.17.0-rc4+/build/vmlinux)
              7fffb70d8234 __GI___libc_write (/usr/lib64/libc-2.26.so)
              7fffb7052c74 _IO_file_write@@GLIBC_2.17 (/usr/lib64/libc-2.26.so)
                  5afc1818 [unknown] ([unknown])
              7fffb7051a60 new_do_write (/usr/lib64/libc-2.26.so)
              7fffb7054638 _IO_do_write@@GLIBC_2.17 (/usr/lib64/libc-2.26.so)
              7fffb7054bbc _IO_file_overflow@@GLIBC_2.17 (/usr/lib64/libc-2.26.so)
              7fffb7055a24 __overflow (/usr/lib64/libc-2.26.so)
              7fffb7044548 _IO_puts (/usr/lib64/libc-2.26.so)
                  10000440 main (/home/sandipan/test)
              7fffb6fe36a0 generic_start_main.isra.0 (/usr/lib64/libc-2.26.so)
              7fffb6fe3898 __libc_start_main (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])
  ...

After applying this patch:

  # perf script

  test  9710 [013] 95614.332431: probe:sys_write: (c0000000004025b0)
          c0000000004025b0 sys_write+0x10 (/lib/modules/4.17.0-rc4+/build/vmlinux)
          c00000000000b9e0 system_call+0x58 (/lib/modules/4.17.0-rc4+/build/vmlinux)
              7fffb70d8234 __GI___libc_write+0x24 (/usr/lib64/libc-2.26.so)
              7fffb7052c74 _IO_file_write@@GLIBC_2.17+0x44 (/usr/lib64/libc-2.26.so)
                  5afc1818 [unknown] ([unknown])
              7fffb7051a60 new_do_write+0x90 (/usr/lib64/libc-2.26.so)
              7fffb7054638 _IO_do_write@@GLIBC_2.17+0x38 (/usr/lib64/libc-2.26.so)
              7fffb7054bbc _IO_file_overflow@@GLIBC_2.17+0x14c (/usr/lib64/libc-2.26.so)
              7fffb7055a24 __overflow+0x64 (/usr/lib64/libc-2.26.so)
              7fffb7044548 _IO_puts+0x218 (/usr/lib64/libc-2.26.so)
                  10000440 main+0x20 (/home/sandipan/test)
              7fffb6fe36a0 generic_start_main.isra.0+0x140 (/usr/lib64/libc-2.26.so)
              7fffb6fe3898 __libc_start_main+0xb8 (/usr/lib64/libc-2.26.so)
                         0 [unknown] ([unknown])
  ...

Signed-off-by: Sandipan Das &lt;sandipan@linux.vnet.ibm.com&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Cc: Ravi Bangoria &lt;ravi.bangoria@linux.ibm.com&gt;
Link: http://lkml.kernel.org/r/20180517063326.6319-2-sandipan@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>tools lib api fs tracing_path: Introduce opendir() method</title>
<updated>2018-05-17T17:50:38+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2018-05-17T17:42:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7014e0e3bf9b0d0b6221eb7d2f8a1f690423dd73'/>
<id>7014e0e3bf9b0d0b6221eb7d2f8a1f690423dd73</id>
<content type='text'>
That takes care of using the right call to get the tracing_path
directory, the one that will end up calling tracing_path_set() to figure
out where tracefs is mounted.

One more step in doing just lazy reading of system structures to reduce
the number of operations done unconditionaly at 'perf' start.

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-42zzi0f274909bg9mxzl81bu@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>
That takes care of using the right call to get the tracing_path
directory, the one that will end up calling tracing_path_set() to figure
out where tracefs is mounted.

One more step in doing just lazy reading of system structures to reduce
the number of operations done unconditionaly at 'perf' start.

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-42zzi0f274909bg9mxzl81bu@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf parse-events: Use get/put_events_file()</title>
<updated>2018-05-17T17:49:36+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2018-05-17T17:27:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=25a7d914274de38637c5199342eb90a297361386'/>
<id>25a7d914274de38637c5199342eb90a297361386</id>
<content type='text'>
Instead of accessing the trace_events_path variable directly, that may
not have been properly initialized wrt detecting where tracefs is
mounted.

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-id7hzn1ydgkxbumeve5wapqz@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>
Instead of accessing the trace_events_path variable directly, that may
not have been properly initialized wrt detecting where tracefs is
mounted.

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-id7hzn1ydgkxbumeve5wapqz@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
