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  1. Apr 30, 2016
    • Ingo Molnar's avatar
      Merge tag 'perf-core-for-mingo-20160429' of... · 03d85a63
      Ingo Molnar authored 
      Merge tag 'perf-core-for-mingo-20160429' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

 into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

User visible changes:

 - Allow generate timestamped suffixed multiple perf.data files upon receiving
   SIGUSR2 in 'perf record', to slice a long running monitoring session, allowing
   to dump uninteresting sessions (Wang Nan)

 - Handle ENOMEM for perf_event_max_stack + PERF_SAMPLE_CALLCHAIN
   in perf_evsel__open_strerror(), showing a more informative
   message when the request call stack depth can't be allocated by
   the kernel (Arnaldo Carvalho de Melo)

Infrastructure changes:

 - Use strbuf for making strings in 'perf probe' (Masami Hiramatsu)

 - Do not use sizeof on pointer type, not a problem since its a pointer to
   pointer, fix none the less. Found by Coccinelle (Vaishali Thakkar)

Cleanups:

 - Fix for Coverity found issues in the bpf feature build test (Florian Fainelli)

Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      03d85a63
  3. Apr 29, 2016
  5. Apr 28, 2016
  7. Apr 27, 2016
    • Ingo Molnar's avatar
      Merge tag 'perf-core-for-mingo-20160427' of... · a8944c5b
      Ingo Molnar authored 
      Merge tag 'perf-core-for-mingo-20160427' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

 into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

User visible changes:

- perf trace --pf maj/min/all works with --call-graph: (Arnaldo Carvalho de Melo)

  Tracing write syscalls and major page faults with callchains while starting
  firefox, limiting the stack to 5 frames:

 # perf trace -e write --pf maj --max-stack 5 firefox
   589.549 ( 0.014 ms): firefox/15377 write(fd: 4, buf: 0x7fff80acc898, count: 151) = 151
                                       [0xfaed] (/usr/lib64/libpthread-2.22.so)
                                       fire_glxtest_process+0x5c (/usr/lib64/firefox/libxul.so)
                                       InstallGdkErrorHandler+0x41 (/usr/lib64/firefox/libxul.so)
                                       XREMain::XRE_mainInit+0x12c (/usr/lib64/firefox/libxul.so)
                                       XREMain::XRE_main+0x1e4 (/usr/lib64/firefox/libxul.so)
   760.704 ( 0.000 ms): firefox/15332 majfault [gtk_tree_view_accessible_get_type+0x0] => /usr/lib64/libgtk-3.so.0.1800.9@0xa0850 (x.)
                                       gtk_tree_view_accessible_get_type+0x0 (/usr/lib64/libgtk-3.so.0.1800.9)
                                       gtk_tree_view_class_intern_init+0x1a54 (/usr/lib64/libgtk-3.so.0.1800.9)
                                       g_type_class_ref+0x6dd (/usr/lib64/libgobject-2.0.so.0.4600.2)
                                       [0x115378] (/usr/lib64/libgnutls.so.30.6.3)

  This automagically selects "--call-graph dwarf", use "--call-graph fp" on systems
  where -fno-omit-frame-pointer was used to built the components of interest, to
  incur in less overhead, or tune "--call-graph dwarf" appropriately, see 'perf record --help'.

- Allow /proc/sys/kernel/perf_event_max_stack, that defaults to the old hard coded value
  of PERF_MAX_STACK_DEPTH (127), useful for huge callstacks for things like Groovy, Ruby, etc,
  and also to reduce overhead by limiting it to a smaller value, upcoming work will allow
  this to be done per-event (Arnaldo Carvalho de Melo)

- Make 'perf trace --min-stack' be honoured by --pf and --event (Arnaldo Carvalho de Melo)

- Make 'perf evlist -v' decode perf_event_attr->branch_sample_type (Arnaldo Carvalho de Melo)

   # perf record --call lbr usleep 1
   # perf evlist -v
   cycles:ppp: ... sample_type: IP|TID|TIME|CALLCHAIN|PERIOD|BRANCH_STACK, ...
            branch_sample_type: USER|CALL_STACK|NO_FLAGS|NO_CYCLES
   #

- Clear dummy entry accumulated period, fixing such 'perf top/report' output
  as: (Kan Liang)

    4769.98%  0.01%  0.00%  0.01%  tchain_edit  [kernel] [k] update_fast_timekeeper

- System calls with pid_t arguments gets them augmented with the COMM event
  more thoroughly:

  # trace -e perf_event_open perf stat -e cycles -p 15608
   6.876 ( 0.014 ms): perf_event_open(attr_uptr: 0x2ae20d8, pid: 15608 (hexchat), cpu: -1, group_fd: -1, flags: FD_CLOEXEC) = 3
   6.882 ( 0.005 ms): perf_event_open(attr_uptr: 0x2ae20d8, pid: 15639 (gmain), cpu: -1, group_fd: -1, flags: FD_CLOEXEC) = 4
   6.889 ( 0.005 ms): perf_event_open(attr_uptr: 0x2ae20d8, pid: 15640 (gdbus), cpu: -1, group_fd: -1, flags: FD_CLOEXEC) = 5
                                                            ^^^^^^^^^^^^^^^^^^
   ^C

- Fix offline module name mismatch issue in 'perf probe' (Ravi Bangoria)

- Fix module probe issue if no dwarf support in (Ravi Bangoria)

Assorted fixes:

- Fix off-by-one in write_buildid() (Andrey Ryabinin)

- Fix segfault when printing callchains in 'perf script' (Chris Phlipot)

- Replace assignment with comparison on assert check in 'perf test' entry (Colin Ian King)

- Fix off-by-one comparison in intel-pt code (Colin Ian King)

- Close target file on error path in 'perf probe' (Masami Hiramatsu)

- Set default kprobe group name if not given in 'perf probe' (Masami Hiramatsu)

- Avoid partial perf_event_header reads (Wang Nan)

Infrastructure changes:

- Update x86's syscall_64.tbl copy, adding preadv2 & pwritev2 (Arnaldo Carvalho de Melo)

- Make the x86 clean quiet wrt syscall table removal (Jiri Olsa)

Cleanups:

- Simplify wrapper for LOCK_PI in 'perf bench futex' (Davidlohr Bueso)

- Remove duplicate const qualifier (Eric Engestrom)

Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      a8944c5b
    • Arnaldo Carvalho de Melo's avatar
      perf tools: Set the maximum allowed stack from /proc/sys/kernel/perf_event_max_stack · 4cb93446
      Arnaldo Carvalho de Melo authored 
      There is an upper limit to what tooling considers a valid callchain,
and it was tied to the hardcoded value in the kernel,
PERF_MAX_STACK_DEPTH (127), now that this can be tuned via a sysctl,
make it read it and use that as the upper limit, falling back to
PERF_MAX_STACK_DEPTH for kernels where this sysctl isn't present.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-yjqsd30nnkogvj5oyx9ghir9@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      4cb93446
    • Arnaldo Carvalho de Melo's avatar
      perf core: Allow setting up max frame stack depth via sysctl · c5dfd78e
      Arnaldo Carvalho de Melo authored 
      

The default remains 127, which is good for most cases, and not even hit
most of the time, but then for some cases, as reported by Brendan, 1024+
deep frames are appearing on the radar for things like groovy, ruby.

And in some workloads putting a _lower_ cap on this may make sense. One
that is per event still needs to be put in place tho.

The new file is:

  # cat /proc/sys/kernel/perf_event_max_stack
  127

Chaging it:

  # echo 256 > /proc/sys/kernel/perf_event_max_stack
  # cat /proc/sys/kernel/perf_event_max_stack
  256

But as soon as there is some event using callchains we get:

  # echo 512 > /proc/sys/kernel/perf_event_max_stack
  -bash: echo: write error: Device or resource busy
  #

Because we only allocate the callchain percpu data structures when there
is a user, which allows for changing the max easily, its just a matter
of having no callchain users at that point.

Reported-and-Tested-by: default avatarBrendan Gregg <brendan.d.gregg@gmail.com>
Reviewed-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarDavid Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: http://lkml.kernel.org/r/20160426002928.GB16708@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      c5dfd78e
    • Arnaldo Carvalho de Melo's avatar
      perf bench: Remove one more die() call · c2a218c6
      Arnaldo Carvalho de Melo authored 
      Propagate the error instead.

Cc: David Ahern <dsahern@gmail.com>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-z6erjg35d1gekevwujoa0223@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      c2a218c6
    • Arnaldo Carvalho de Melo's avatar
      perf tools: Update x86's syscall_64.tbl, adding preadv2 & pwritev2 · 042a1810
      Arnaldo Carvalho de Melo authored 
      Introduced in commit 4babf2c5 ("x86: wire up preadv2 and pwritev2").

This will make 'perf trace' aware of them.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-vojoylgce2cetsy36446s5ny@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      042a1810
    • Ravi Bangoria's avatar
      perf probe: Fix module probe issue if no dwarf support · c61fb959
      Ravi Bangoria authored 
      

Perf is not able to register probe in kernel module when dwarf supprt
is not there(and so it goes for symtab). Perf passes full path of
module where only module name is required which is causing the problem.
This patch fixes this issue.

Before applying patch:

  $ dpkg -s libdw-dev
  dpkg-query: package 'libdw-dev' is not installed and no information is...

  $ sudo ./perf probe -m /linux/samples/kprobes/kprobe_example.ko kprobe_init
  Added new event:
    probe:kprobe_init (on kprobe_init in /linux/samples/kprobes/kprobe_example.ko)

  You can now use it in all perf tools, such as:

  perf record -e probe:kprobe_init -aR sleep 1

  $ sudo cat /sys/kernel/debug/tracing/kprobe_events
  p:probe/kprobe_init /linux/samples/kprobes/kprobe_example.ko:kprobe_init

  $ sudo ./perf record -a -e probe:kprobe_init
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.105 MB perf.data ]

  $ sudo ./perf script 	# No output here

After applying patch:

  $ sudo ./perf probe -m /linux/samples/kprobes/kprobe_example.ko kprobe_init
  Added new event:
    probe:kprobe_init    (on kprobe_init in kprobe_example)

  You can now use it in all perf tools, such as:

  perf record -e probe:kprobe_init -aR sleep 1

  $ sudo cat /sys/kernel/debug/tracing/kprobe_events
  p:probe/kprobe_init kprobe_example:kprobe_init

  $ sudo ./perf record -a -e probe:kprobe_init
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.105 MB perf.data (2 samples) ]

  $ sudo ./perf script
  insmod 13990 [002]  5961.216833: probe:kprobe_init: ...
  insmod 13995 [002]  5962.889384: probe:kprobe_init: ...

Signed-off-by: default avatarRavi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1461680741-12517-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      c61fb959
    • Ravi Bangoria's avatar
      perf probe: Fix offline module name missmatch issue · 63a29613
      Ravi Bangoria authored 
      

Perf can add a probe on kernel module which has not been loaded yet.

The current implementation finds the module name from path. But if the
filename is different from the actual module name then perf fails to
register a probe while loading module because of mismatch in the names.

For example, samples/kobject/kobject-example.ko is loaded as
kobject_example.

Before applying patch:

  $ sudo ./perf probe -m /linux/samples/kobject/kobject-example.ko foo_show
    Added new event:
      probe:foo_show       (on foo_show in kobject-example)

    You can now use it in all perf tools, such as:

    perf record -e probe:foo_show -aR sleep 1

  $ cat /sys/kernel/debug/tracing/kprobe_events
    p:probe/foo_show kobject-example:foo_show

  $ insmod kobject-example.ko

  $ lsmod
    Module                  Size  Used by
    kobject_example        16384  0

  Generate read to /sys/kernel/kobject_example/foo while recording data
  with below command
  $ sudo ./perf record -e probe:foo_show -a
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.093 MB perf.data ]

  $./perf report --stdio -F overhead,comm,dso,sym
    Error:
    The perf.data.old file has no samples!

After applying patch:

  $ sudo ./perf probe -m /linux/samples/kobject/kobject-example.ko foo_show
    Added new event:
      probe:foo_show       (on foo_show in kobject_example)

    You can now use it in all perf tools, such as:

    perf record -e probe:foo_show -aR sleep 1

  $ sudo cat /sys/kernel/debug/tracing/kprobe_events
    p:probe/foo_show kobject_example:foo_show

  $ insmod kobject-example.ko

  $ lsmod
    Module                  Size  Used by
    kobject_example        16384  0

  Generate read to /sys/kernel/kobject_example/foo while recording data
  with below command
  $ sudo ./perf record -e probe:foo_show -a
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.097 MB perf.data (8 samples) ]

  $ sudo ./perf report  --stdio -F overhead,comm,dso,sym
    ...
    # Samples: 8  of event 'probe:foo_show'
    # Event count (approx.): 8
    #
    # Overhead  Command  Shared Object      Symbol
    # ........  .......  .................  ............
    #
       100.00%  cat      [kobject_example]  [k] foo_show

Signed-off-by: default avatarRavi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1461680741-12517-2-git-send-email-ravi.bangoria@linux.vnet.ibm.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      63a29613
    • Arnaldo Carvalho de Melo's avatar
      perf trace: Read thread's COMM from /proc when not set · 073e5fca
      Arnaldo Carvalho de Melo authored 
      We get notifications for threads that gets created while we're tracing,
but for preexisting threads we may end not having synthesized them, like
when tracing a 'perf trace' session that will use '--pid' to trace some
other thread.

And besides we should probably stop synthesizing those records and
instead read thread information in a lazy way, i.e. just when we need,
like done in this patch:

Now the 'pid_t' argument in 'perf_event_open' gets translated to a COMM:

  # perf trace -e perf_event_open perf stat -e cycles -p 31601
     0.027 ( 0.027 ms): perf/23393 perf_event_open(attr_uptr: 0x2fdd0d8, pid: 31601 (abrt-dump-journ), cpu: -1, group_fd: -1, flags: FD_CLOEXEC)
                                                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= 3
^C

And in other syscalls containing pid_t without thread->comm_set at the
time of the formatting.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ioeps6dlwst17d6oozc9shtk@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      073e5fca
    • Arnaldo Carvalho de Melo's avatar
      perf thread: Introduce method to set comm from /proc/pid/self · 2f3027ac
      Arnaldo Carvalho de Melo authored 
      Will be used for lazy comm loading in 'perf trace'.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-7ogbkuoka1y2qsmcckqxvl5m@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      2f3027ac
    • Arnaldo Carvalho de Melo's avatar
      tools lib api fs: Add helper to read string from procfs file · 4bd112df
      Arnaldo Carvalho de Melo authored 
      To read things like /proc/self/comm.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ztpkbmseidt0hq2psr46o0h9@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      4bd112df
    • Arnaldo Carvalho de Melo's avatar
      perf trace: Do not beautify the 'pid' parameter as a simple integer · ccd9b2a7
      Arnaldo Carvalho de Melo authored 
      Leave it alone so that it ends up assigned to SCA_PID via its type,
'pid_t', that will look up the pid on the machine thread rb_tree and
possibly find its COMM.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-r7dujgmhtxxfajuunpt1bkuo@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      ccd9b2a7
    • Arnaldo Carvalho de Melo's avatar
      perf trace: Move perf_flags beautifier to tools/perf/trace/beauty/ · 62de344e
      Arnaldo Carvalho de Melo authored 
      To reduce the size of builtin-trace.c.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-8r3gmymyn3r0ynt4yuzspp9g@git.kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      62de344e
    • Masami Hiramatsu's avatar
      perf probe: Set default kprobe group name if it is not given · 2a12ec13
      Masami Hiramatsu authored 
      

Set kprobe group name as "probe" if it is not given.

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160426090413.11891.95640.stgit@devbox


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      2a12ec13
    • Masami Hiramatsu's avatar
      perf probe: Let probe_file__add_event return 0 if succeeded · 6ed0720a
      Masami Hiramatsu authored 
      

Since other methods return 0 if succeeded (or filedesc), let
probe_file__add_event() return 0 instead of the length of written bytes.

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160426090303.11891.18232.stgit@devbox


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      6ed0720a
    • Masami Hiramatsu's avatar
      perf tools: Add lsdir() helper to read a directory · e1ce726e
      Masami Hiramatsu authored 
      

As a utility function, add lsdir() which reads given directory and store
entry name into a strlist.  lsdir accepts a filter function so that user
can filter out unneeded entries.

Signed-off-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160426090242.11891.79014.stgit@devbox


[ Do not use the 'dirname' it is used in some distros ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      e1ce726e
  9. Apr 26, 2016