Skip to content

cloud-kernel
cloud-kernel

openanolis / cloud-kernel
1 年多 前同步成功

通知 160
Star 36
Fork 7
cloud-kernel
cloud-kernel
切换分支/标签
  1. 29 10月, 2013 1 次提交
  3. 18 10月, 2013 2 次提交
    • A
      perf trace: Improve messages related to /proc/sys/kernel/perf_event_paranoid · a8f23d8f
      由 Arnaldo Carvalho de Melo 提交于 
      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: 0x2544af0, count: 4096     ) = 8
      23.161 ( 0.002 ms): Xorg/729 read(fd: 31, buf: 0x2544af0, 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: NArnaldo Carvalho de Melo <acme@redhat.com>
      a8f23d8f
    • A
      perf evlist: Introduce perf_evlist__strerror_tp method · 6ef068cb
      由 Arnaldo Carvalho de Melo 提交于 
      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: NArnaldo Carvalho de Melo <acme@redhat.com>
      6ef068cb
  5. 11 10月, 2013 1 次提交
    • J
      perf evlist: Fix perf_evlist__mmap_read event overflow · a65cb4b9
      由 Jiri Olsa 提交于 
      The perf_evlist__mmap_read used 'union perf_event' as a placeholder for
event crossing the mmap boundary.

This is ok for sample shorter than ~PATH_MAX. However we could grow up
to the maximum sample size which is 16 bits max.

I hit this overflow issue when using 'perf top -G dwarf' which produces
sample with the size around 8192 bytes.  We could configure any valid
sample size here using: '-G dwarf,size'.

Using array with sample max size instead for the event placeholder. Also
adding another safe check for the dynamic size of the user stack.

TODO: The 'struct perf_mmap' is quite big now, maybe we could use some
lazy allocation for event_copy size.
Signed-off-by: NJiri Olsa <jolsa@redhat.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1380721599-24285-1-git-send-email-jolsa@redhat.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      a65cb4b9
  7. 09 10月, 2013 2 次提交
  9. 03 9月, 2013 1 次提交
  11. 30 8月, 2013 2 次提交
  13. 08 8月, 2013 2 次提交
  15. 16 3月, 2013 5 次提交
  17. 07 2月, 2013 1 次提交
    • D
      perf evlist: Make event_copy local to mmaps · 0479b8b9
      由 David Ahern 提交于 
      I am getting segfaults *after* the time sorting of perf samples where
the event type is off the charts:

(gdb) bt
\#0  0x0807b1b2 in hists__inc_nr_events (hists=0x80a99c4, type=1163281902) at util/hist.c:1225
\#1  0x08070795 in perf_session_deliver_event (session=0x80a9b90, event=0xf7a6aff8, sample=0xffffc318, tool=0xffffc520,
    file_offset=0) at util/session.c:884
\#2  0x0806f9b9 in flush_sample_queue (s=0x80a9b90, tool=0xffffc520) at util/session.c:555
\#3  0x0806fc53 in process_finished_round (tool=0xffffc520, event=0x0, session=0x80a9b90) at util/session.c:645

This is bizarre because the event has already been processed once --
before it was added to the samples queue -- and the event was found to
be sane at that time.

There seem to be 2 causes:

1. perf_evlist__mmap_read updates the read location even though there
are outstanding references to events sitting in the mmap buffers via the
ordered samples queue.

2. There is a single evlist->event_copy for all evlist entries.
event_copy is used to handle an event wrapping at the mmap buffer
boundary.

This patch addresses the second problem - making event_copy local to
each perf_mmap. With this change my highly repeatable use case no longer
fails.

The first problem is much more complicated and will be the subject of a
future patch.
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1360098762-61827-1-git-send-email-dsahern@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      0479b8b9
  19. 01 2月, 2013 1 次提交
  21. 12 12月, 2012 1 次提交
  23. 03 10月, 2012 2 次提交
  25. 27 9月, 2012 2 次提交
  27. 26 9月, 2012 1 次提交
  29. 07 9月, 2012 1 次提交
  31. 15 8月, 2012 3 次提交
    • A
      perf evlist: Introduce evsel list accessors · 0c21f736
      由 Arnaldo Carvalho de Melo 提交于 
      To replace the longer list_entry constructs for things that are widely
used:

	perf_evlist__{first,last}(evlist)
	perf_evsel__next(evsel)
Acked-by: NJiri Olsa <jolsa@redhat.com>
Acked-by: NNamhyung Kim <namhyung@gmail.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: Namhyung Kim <namhyung@gmail.com>
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-ng7azq26wg1jd801qqpcozwp@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      0c21f736
    • A
      perf evlist: Rename __group method to __set_leader · 63dab225
      由 Arnaldo Carvalho de Melo 提交于 
      Just like was done for parse_events__set_leader.

Also we need to have the list_entry set_leader method in evlist.c so that we
don't grow another dep in the python binding:

 # ~acme/git/linux/tools/perf/python/twatch.py
 Traceback (most recent call last):
   File "/home/acme/git/linux/tools/perf/python/twatch.py", line 16, in <module>
     import perf
 ImportError: /home/acme/git/build/perf/python/perf.so: undefined symbol: parse_events__set_leader

And also remove a pr_debug from evsel.c so that we avoid this one too:

 # ~acme/git/linux/tools/perf/python/twatch.py
 Traceback (most recent call last):
   File "/home/acme/git/linux/tools/perf/python/twatch.py", line 16, in <module>
     import perf
 ImportError: /home/acme/git/build/perf/python/perf.so: undefined symbol: eprintf
Acked-by: NJiri Olsa <jolsa@redhat.com>
Acked-by: NNamhyung Kim <namhyung@gmail.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: Namhyung Kim <namhyung@gmail.com>
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-0hk9dazg9pora9jylkqngovm@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      63dab225
    • J
      perf tools: Enable grouping logic for parsed events · 6a4bb04c
      由 Jiri Olsa 提交于 
      This patch adds a functionality that allows to create event groups
based on the way they are specified on the command line. Adding
functionality to the '{}' group syntax introduced in earlier patch.

The current '--group/-g' option behaviour remains intact. If you
specify it for record/stat/top command, all the specified events
become members of a single group with the first event as a group
leader.

With the new '{}' group syntax you can create group like:
  # perf record -e '{cycles,faults}' ls

resulting in single event group containing 'cycles' and 'faults'
events, with cycles event as group leader.

All groups are created with regards to threads and cpus. Thus
recording an event group within a 2 threads on server with
4 CPUs will create 8 separate groups.

Examples (first event in brackets is group leader):

  # 1 group (cpu-clock,task-clock)
  perf record --group -e cpu-clock,task-clock ls
  perf record -e '{cpu-clock,task-clock}' ls

  # 2 groups (cpu-clock,task-clock) (minor-faults,major-faults)
  perf record -e '{cpu-clock,task-clock},{minor-faults,major-faults}' ls

  # 1 group (cpu-clock,task-clock,minor-faults,major-faults)
  perf record --group -e cpu-clock,task-clock -e minor-faults,major-faults ls
  perf record -e '{cpu-clock,task-clock,minor-faults,major-faults}' ls

  # 2 groups (cpu-clock,task-clock) (minor-faults,major-faults)
  perf record -e '{cpu-clock,task-clock} -e '{minor-faults,major-faults}' \
   -e instructions ls

  # 1 group
  # (cpu-clock,task-clock,minor-faults,major-faults,instructions)
  perf record --group -e cpu-clock,task-clock \
   -e minor-faults,major-faults -e instructions ls perf record -e
'{cpu-clock,task-clock,minor-faults,major-faults,instructions}' ls

It's possible to use standard event modifier for a group, which spans
over all events in the group and updates each event modifier settings,
for example:

  # perf record -r '{faults:k,cache-references}:p'

resulting in ':kp' modifier being used for 'faults' and ':p' modifier
being used for 'cache-references' event.
Reviewed-by: NNamhyung Kim <namhyung@kernel.org>
Signed-off-by: NJiri Olsa <jolsa@redhat.com>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ulrich Drepper <drepper@gmail.com>
Link: http://lkml.kernel.org/n/tip-ho42u0wcr8mn1otkalqi13qp@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      6a4bb04c
  33. 02 8月, 2012 2 次提交
  35. 28 6月, 2012 1 次提交
    • A
      perf tools: Stop using a global trace events description list · da378962
      由 Arnaldo Carvalho de Melo 提交于 
      The pevent thing is per perf.data file, so I made it stop being static
and become a perf_session member, so tools processing perf.data files
use perf_session and _there_ we read the trace events description into
session->pevent and then change everywhere to stop using that single
global pevent variable and use the per session one.

Note that it _doesn't_ fall backs to trace__event_id, as we're not
interested at all in what is present in the
/sys/kernel/debug/tracing/events in the workstation doing the analysis,
just in what is in the perf.data file.

This patch also introduces perf_session__set_tracepoints_handlers that
is the perf perf.data/session way to associate handlers to tracepoint
events by resolving their IDs using the events descriptions stored in a
perf.data file. Make 'perf sched' use it.
Reported-by: NDmitry Antipov <dmitry.antipov@linaro.org>
Tested-by: NDmitry Antipov <dmitry.antipov@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linaro-dev@lists.linaro.org
Cc: patches@linaro.org
Link: http://lkml.kernel.org/r/20120625232016.GA28525@infradead.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      da378962
  37. 31 5月, 2012 1 次提交
    • A
      perf stat: Initialize default events wrt exclude_{guest,host} · 79695e1b
      由 Arnaldo Carvalho de Melo 提交于 
      When no event is specified the tools use perf_evlist__add_default(), that will
call event_attr_init to initialize the KVM exclusion bits.

When the change was made to the tools so that by default guest samples would be
excluded, the changes were made just to the parsing routines and to
perf_evlist__add_default(), not to perf_evlist__add_attrs, that is used so far
just by perf stat to add multiple events, according to the level of detail
specified.

Recently the tools were changed to reconstruct the event name from all the
details in perf_event_attr, not just from .type and .config, but taking into
account all the feature bits (.exclude_{guest,host,user,kernel,etc},
.precise_ip, etc).

That is when we noticed that the default for perf stat wasn't the one for the
rest of the tools, i.e. the .exclude_guest bit wasn't being set.

I.e. the default, that doesn't call event_attr_init was showing the :HG
modifier:

  $ perf stat usleep 1

   Performance counter stats for 'usleep 1':

            0.942119 task-clock                #    0.454 CPUs utilized
                   1 context-switches          #    0.001 M/sec
                   0 CPU-migrations            #    0.000 K/sec
                 126 page-faults               #    0.134 M/sec
             693,193 cycles:HG                 #    0.736 GHz                     [40.11%]
             407,461 stalled-cycles-frontend:HG #   58.78% frontend cycles idle    [72.29%]
             365,403 stalled-cycles-backend:HG #   52.71% backend  cycles idle
             465,982 instructions:HG           #    0.67  insns per cycle
                                               #    0.87  stalled cycles per insn
              89,760 branches:HG               #   95.275 M/sec
               6,178 branch-misses:HG          #    6.88% of all branches

         0.002077228 seconds time elapsed

While if one explicitely specifies the same events, which will make the parsing code
to be called and thus event_attr_init is called:

  $ perf stat -e task-clock,context-switches,migrations,page-faults,cycles,stalled-cycles-frontend,stalled-cycles-backend,instructions,branches,branch-misses usleep 1

   Performance counter stats for 'usleep 1':

            1.040349 task-clock                #    0.500 CPUs utilized
                   2 context-switches          #    0.002 M/sec
                   0 CPU-migrations            #    0.000 K/sec
                 127 page-faults               #    0.122 M/sec
             587,966 cycles                    #    0.565 GHz                     [13.18%]
             459,167 stalled-cycles-frontend   #   78.09% frontend cycles idle
             390,249 stalled-cycles-backend    #   66.37% backend  cycles idle
             504,006 instructions              #    0.86  insns per cycle
                                               #    0.91  stalled cycles per insn
              96,455 branches                  #   92.714 M/sec
               6,522 branch-misses             #    6.76% of all branches         [96.12%]

         0.002078681 seconds time elapsed

Fix it by introducing a perf_evlist__add_default_attrs method that will call
evlist_attr_init in all the perf_event_attr entries before adding the events.
Reported-by: NIngo Molnar <mingo@kernel.org>
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: Namhyung Kim <namhyung@gmail.com>
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-4eysr236r0pgiyum9epwxw7s@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      79695e1b
  39. 03 5月, 2012 1 次提交
  41. 14 2月, 2012 1 次提交
  43. 02 2月, 2012 1 次提交
  45. 25 1月, 2012 1 次提交
  47. 29 11月, 2011 2 次提交
    • A
      perf evlist: Always do automatic allocation of pollfd and mmap structures · 806fb630
      由 Arnaldo Carvalho de Melo 提交于 
      At first tools were required to do that, but while writing the python
bindings to simplify the API I made them auto-allocate when needed.

This just makes record, stat and top use that auto allocation,
simplifying them a bit.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.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-iokhcvkzzijr3keioubx8hlq@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      806fb630
    • A
      perf tools: Save some loops using perf_evlist__id2evsel · ee29be62
      由 Arnaldo Carvalho de Melo 提交于 
      Since we already ask for PERF_SAMPLE_ID and use it to quickly find the
associated evsel, add handler func + data to struct perf_evsel to avoid
using chains of if(strcmp(event_name)) and also to avoid all the linear
list searches via trace_event_find.

To demonstrate the technique convert 'perf sched' to it:

 # perf sched record sleep 5m

And then:

 Performance counter stats for '/tmp/oldperf sched lat':

        646.929438 task-clock                #    0.999 CPUs utilized
                 9 context-switches          #    0.000 M/sec
                 0 CPU-migrations            #    0.000 M/sec
            20,901 page-faults               #    0.032 M/sec
     1,290,144,450 cycles                    #    1.994 GHz
   <not supported> stalled-cycles-frontend
   <not supported> stalled-cycles-backend
     1,606,158,439 instructions              #    1.24  insns per cycle
       339,088,395 branches                  #  524.151 M/sec
         4,550,735 branch-misses             #    1.34% of all branches

       0.647524759 seconds time elapsed

Versus:

 Performance counter stats for 'perf sched lat':

        473.564691 task-clock                #    0.999 CPUs utilized
                 9 context-switches          #    0.000 M/sec
                 0 CPU-migrations            #    0.000 M/sec
            20,903 page-faults               #    0.044 M/sec
       944,367,984 cycles                    #    1.994 GHz
   <not supported> stalled-cycles-frontend
   <not supported> stalled-cycles-backend
     1,442,385,571 instructions              #    1.53  insns per cycle
       308,383,106 branches                  #  651.195 M/sec
         4,481,784 branch-misses             #    1.45% of all branches

       0.474215751 seconds time elapsed

[root@emilia ~]#

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.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-1kbzpl74lwi6lavpqke2u2p3@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      ee29be62
  49. 28 11月, 2011 2 次提交