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  1. 21 Oct, 2013 16 commits
  3. 18 Oct, 2013 1 commit
  5. 17 Oct, 2013 3 commits
    • Arnaldo Carvalho de Melo's avatar
      perf trace: Improve messages related to /proc/sys/kernel/perf_event_paranoid · a8f23d8f
      Arnaldo Carvalho de Melo authored 
      kernel/events/core.c has:

  /*
   * perf event paranoia level:
   *  -1 - not paranoid at all
   *   0 - disallow raw tracepoint access for unpriv
   *   1 - disallow cpu events for unpriv
   *   2 - disallow kernel profiling for unpriv
   */
  int sysctl_perf_event_paranoid __read_mostly = 1;

So, with the default being 1, a non-root user can trace his stuff:

  [acme@zoo ~]$ cat /proc/sys/kernel/perf_event_paranoid
  1
  [acme@zoo ~]$ yes > /dev/null &
  [1] 15338
  [acme@zoo ~]$ trace -p 15338 | head -5
       0.005 ( 0.005 ms): write(fd: 1</dev/null>, buf: 0x7fe6db765000, count: 4096 ) = 4096
       0.045 ( 0.001 ms): write(fd: 1</dev/null>, buf: 0x7fe6db765000, count: 4096 ) = 4096
       0.085 ( 0.001 ms): write(fd: 1</dev/null>, buf: 0x7fe6db765000, count: 4096 ) = 4096
       0.125 ( 0.001 ms): write(fd: 1</dev/null>, buf: 0x7fe6db765000, count: 4096 ) = 4096
       0.165 ( 0.001 ms): write(fd: 1</dev/null>, buf: 0x7fe6db765000, count: 4096 ) = 4096
  [acme@zoo ~]$
  [acme@zoo ~]$ trace --duration 1 sleep 1
    1002.148 (1001.218 ms): nanosleep(rqtp: 0x7fff46c79250                           ) = 0
  [acme@zoo ~]$
  [acme@zoo ~]$ trace -- usleep 1 | tail -5
       0.905 ( 0.002 ms): brk(                                                     ) = 0x1c82000
       0.910 ( 0.003 ms): brk(brk: 0x1ca3000                                       ) = 0x1ca3000
       0.913 ( 0.001 ms): brk(                                                     ) = 0x1ca3000
       0.990 ( 0.059 ms): nanosleep(rqtp: 0x7fffe31a3280                           ) = 0
       0.995 ( 0.000 ms): exit_group(
  [acme@zoo ~]$

But can't do system wide tracing:

  [acme@zoo ~]$ trace
  Error:	Operation not permitted.
  Hint:	Check /proc/sys/kernel/perf_event_paranoid setting.
  Hint:	For system wide tracing it needs to be set to -1.
  Hint:	The current value is 1.
  [acme@zoo ~]$

  [acme@zoo ~]$ trace --cpu 0
  Error:	Operation not permitted.
  Hint:	Check /proc/sys/kernel/perf_event_paranoid setting.
  Hint:	For system wide tracing it needs to be set to -1.
  Hint:	The current value is 1.
  [acme@zoo ~]$

If the paranoid level is >= 2, i.e. turn this perf stuff off for !root users:

  [acme@zoo ~]$ sudo sh -c 'echo 2 > /proc/sys/kernel/perf_event_paranoid'
  [acme@zoo ~]$ cat /proc/sys/kernel/perf_event_paranoid
  2
  [acme@zoo ~]$
  [acme@zoo ~]$ trace usleep 1
  Error:	Permission denied.
  Hint:	Check /proc/sys/kernel/perf_event_paranoid setting.
  Hint:	For your workloads it needs to be <= 1
  Hint:	For system wide tracing it needs to be set to -1.
  Hint:	The current value is 2.
  [acme@zoo ~]$
  [acme@zoo ~]$ trace
  Error:	Permission denied.
  Hint:	Check /proc/sys/kernel/perf_event_paranoid setting.
  Hint:	For your workloads it needs to be <= 1
  Hint:	For system wide tracing it needs to be set to -1.
  Hint:	The current value is 2.
  [acme@zoo ~]$
  [acme@zoo ~]$ trace --cpu 1
  Error:	Permission denied.
  Hint:	Check /proc/sys/kernel/perf_event_paranoid setting.
  Hint:	For your workloads it needs to be <= 1
  Hint:	For system wide tracing it needs to be set to -1.
  Hint:	The current value is 2.
  [acme@zoo ~]$

If the user manages to get what he/she wants, convincing root not
to be paranoid at all...

  [root@zoo ~]# echo -1 > /proc/sys/kernel/perf_event_paranoid
  [root@zoo ~]# cat /proc/sys/kernel/perf_event_paranoid
  -1
  [root@zoo ~]#

  [acme@zoo ~]$ ps -eo user,pid,comm | grep Xorg
  root       729 Xorg
  [acme@zoo ~]$
  [acme@zoo ~]$ trace -a --duration 0.001 -e \!select,ioctl,writev | grep Xorg  | head -5
      23.143 ( 0.003 ms): Xorg/729 setitimer(which: REAL, value: 0x7fffaadf16e0 ) = 0
      23.152 ( 0.004 ms): Xorg/729 read(fd: 31, buf: 0x2544af03, count: 4096     ) = 8
      23.161 ( 0.002 ms): Xorg/729 read(fd: 31, buf: 0x2544af03, count: 4096     ) = -1 EAGAIN Resource temporarily unavailable
      23.175 ( 0.002 ms): Xorg/729 setitimer(which: REAL, value: 0x7fffaadf16e0 ) = 0
      23.235 ( 0.002 ms): Xorg/729 setitimer(which: REAL, value: 0x7fffaadf16e0 ) = 0
  [acme@zoo ~]$

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-di28olfwd28rvkox7v3hqhu1@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      a8f23d8f
    • Arnaldo Carvalho de Melo's avatar
      perf tools: Introduce filename__read_int helper · 97a07f10
      Arnaldo Carvalho de Melo authored 
      Just opens a file and calls atoi() in at most its first 64 bytes.

To read things like /proc/sys/kernel/perf_event_paranoid.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-669q04c5tou5pnt8jtiz6y2r@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      97a07f10
    • Arnaldo Carvalho de Melo's avatar
      perf evlist: Introduce perf_evlist__strerror_tp method · 6ef068cb
      Arnaldo Carvalho de Melo authored 
      Out of 'perf trace', should be used by other tools that uses
tracepoints.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ramkumar Ramachandra <artagnon@gmail.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-lyvtxhchz4ga8fwht15x8wou@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      6ef068cb
  7. 16 Oct, 2013 3 commits
    • Arnaldo Carvalho de Melo's avatar
      perf trace: Improve event processing exit · ba209f85
      Arnaldo Carvalho de Melo authored 
      We need to differentiate SIGCHLD from SIGINT, the later should cause as
immediate as possible exit, while the former should wait to process the
events that may be perceived in the ring buffer after the SIGCHLD is
handled.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-vf6n57ewm3mjy2sz6r491hus@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      ba209f85
    • Arnaldo Carvalho de Melo's avatar
      perf trace: Use vfs_getname hook if available · c522739d
      Arnaldo Carvalho de Melo authored 
      Initially it tries to find a probe:vfs_getname that should be setup
with:

 perf probe 'vfs_getname=getname_flags:65 pathname=result->name:string'

or with slight changes to cope with code flux in the getname_flags code.

In the future, if a "vfs:getname" tracepoint becomes available, then it
will be preferred.

This is not strictly required and more expensive method of reading the
/proc/pid/fd/ symlink will be used when the fd->path array entry is not
populated by a previous vfs_getname + open syscall ret sequence.

As with any other 'perf probe' probe the setup must be done just once
and the probe will be left inactive, waiting for users, be it 'perf
trace' of any other tool.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ujg8se8glq5izmu8cdkq15po@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      c522739d
    • Arnaldo Carvalho de Melo's avatar
      perf trace: Split fd -> pathname array handling · 97119f37
      Arnaldo Carvalho de Melo authored 
      So that the part that grows the array as needed is untied from the code
that reads the /proc/pid/fd symlink and can be used for the vfs_getname
hook that will set the fd -> path translation too, when available.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-ydo5rumyv9hdc1vsfmqamugs@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      97119f37
  9. 15 Oct, 2013 3 commits
    • Arnaldo Carvalho de Melo's avatar
      perf scripting perl: Fix build error on Fedora 12 · 6650b181
      Arnaldo Carvalho de Melo authored 
      Cast __u64 to u64 to silence this warning on older distros, such as
Fedora 12:

    CC       /tmp/build/perf/util/scripting-engines/trace-event-perl.o
  cc1: warnings being treated as errors
  util/scripting-engines/trace-event-perl.c: In function ‘perl_process_tracepoint’:
  util/scripting-engines/trace-event-perl.c:285: error: format ‘%lu’ expects type ‘long unsigned int’, but argument 2 has type ‘__u64’
  make[1]: *** [/tmp/build/perf/util/scripting-engines/trace-event-perl.o] Error 1
  make: *** [install] Error 2
  make: Leaving directory `/home/acme/git/linux/tools/perf'
  [acme@fedora12 linux]$
Reported-by: default avatarWaiman Long <Waiman.Long@hp.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Waiman Long <Waiman.Long@hp.com>
Link: http://lkml.kernel.org/n/tip-nlxofdqcdjfm0w9o6bgq4kqv@git.kernel.org
Link: http://lkml.kernel.org/r/1381265120-58532-1-git-send-email-Waiman.Long@hp.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      6650b181
    • Ingo Molnar's avatar
      Merge tag 'perf-core-for-mingo' of... · 1ff9ecf7
      Ingo Molnar authored 
      Merge tag 'perf-core-for-mingo' 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:

  * kcore annotation improvements, including build-id cache support,
    multi map 'call' instruction navigation fixes, kcore address
    validation, objdump workarounds. From Adrian Hunter.

  * 'trace' beautifiers for lots of syscall arguments, from Arnaldo Carvalho de Melo.

  * More compact 'trace' output by suppressing zeroed args, from Arnaldo Carvalho de Melo.

  * Show thread COMM by default in 'trace', from Arnaldo Carvalho de Melo.

  * Show path associated with fd in live sessions, using a 'vfs_getname'
    'perf probe' created dynamic tracepoint or by looking at /proc/pid/fd, from Arnaldo Carvalho de Melo.

  * Memory and mmap leak fixes from Chenggang Qin.

  * Add option to show full timestamp in 'trace', from David Ahern.

  * Add 'record' command in 'trace', to record raw_syscalls:*, from David Ahern.

  * Add summary option to dump syscall statistics in 'trace', from David Ahern.

  * Fix comm resolution in 'trace' when reading events from file, from David Ahern.

  * Improved messages when doing profiling in all or a subset of CPUs
    using a workload as the session delimitator, as in:

     'perf stat --cpu 0,2 sleep 10s'

    from Arnaldo Carvalho de Melo.

  * Add units to nanosec-based counters in 'perf stat', from David Ahern.

  * Assorted build fixes for from David Ahern and Jiri Olsa.

  * 'perf lock' fixes and cleanups, from Davidlohr Bueso.

  * Memory leak fixes in 'perf test', from Felipe Pena.

  * Build system super speedups, from Ingo Molnar.

  * Fix mmap_read event overflow, from Jiri Olsa.

  * Code cleanups from Jiri Olsa.

  * Allow specifying B/K/M/G unit to the --mmap-pages arguments, from Jiri Olsa.

  * Separate the GTK support in a separate libperf-gtk.so DSO, that is
    only loaded when --gtk is specified, from Namhyung Kim.

  * Fixes for some memory leaks, from Namhyumg Kim.

  * Fix srcline sort key behavior, from Namhyung Kim.

  * Fix failing assertions in numa bench, from Petr Holasek.

  * perf bash completion fixes and improvements from Ramkumar Ramachandra.

  * Improve error messages in 'trace', providing hints about system configuration
    steps needed for using it, from Ramkumar Ramachandra.

  * Remove bogus info when using 'perf stat' -e cycles/instructions, from
    Ramkumar Ramachandra.

  * Support for Openembedded/Yocto -dbg packages, from Ricardo Ribalda Delgado.

  * Implement addr2line directly using libbfd, from Roberto Vitillo.

  * Add new option --ignore-vmlinux for perf top, from Willy Tarreau.
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      1ff9ecf7
    • Ingo Molnar's avatar
      Merge tag 'v3.12-rc5' into perf/core · 426ee9e3
      Ingo Molnar authored 
      Merge Linux v3.12-rc5, to pick up the latest fixes.
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      426ee9e3
  11. 14 Oct, 2013 14 commits
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