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  1. 23 3月, 2015 5 次提交
  3. 22 3月, 2015 6 次提交
  5. 21 3月, 2015 1 次提交
    • M
      perf tools: Fix race in build_id_cache__add_s() · 0635b0f7
      由 Milos Vyletel 提交于 
      int build_id_cache__add_s(const char *sbuild_id, const char *debugdir,
                          const char *name, bool is_kallsyms, bool is_vdso)
{
...
        if (access(filename, F_OK)) {
               ^--------------------------------------------------------- [1]
                if (is_kallsyms) {
                         if (copyfile("/proc/kallsyms", filename))
                                goto out_free;
                } else if (link(realname, filename) && copyfile(name, filename))
                             ^-----------------------------^------------- [2]
                                                            \------------ [3]
                        goto out_free;
        }
...

When multiple instances of perf record get to [1] at more or less same time and
run access() one or more may get failure because the file does not exist yet
(since the first instance did not have chance to link it yet).

At this point the race moves to link() at [2] where first thread to get
there links file and goes on but second one gets -EEXIST so it runs
copyfile [3] which truncates the file.

reproducer:

rm -rf /root/.debug
for cpu in $(awk '/processor/ {print $3}' /proc/cpuinfo); do
	perf record -a -v -T -F 1000 -C $cpu \
		-o perf-${cpu}.data sleep 5 2> /dev/null &
done
wait

and simply search for empty files by:

find /lib/modules/`uname -r`/kernel/* -size 0
Signed-off-by: NMilos Vyletel <milos@redhat.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1426847846-11112-1-git-send-email-milos@redhat.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      0635b0f7
  7. 20 3月, 2015 2 次提交
  9. 18 3月, 2015 2 次提交
  11. 13 3月, 2015 1 次提交
  13. 12 3月, 2015 12 次提交
  15. 11 3月, 2015 2 次提交
  17. 03 3月, 2015 1 次提交
    • A
      perf tools: Reference count struct thread · f3b623b8
      由 Arnaldo Carvalho de Melo 提交于 
      We need to do that to stop accumulating entries in the dead_threads
linked list, i.e. we were keeping references to threads in struct hists
that continue to exist even after a thread exited and was removed from
the machine threads rbtree.

We still keep the dead_threads list, but just for debugging, allowing us
to iterate at any given point over the threads that still are referenced
by things like struct hist_entry.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-3ejvfyed0r7ue61dkurzjux4@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      f3b623b8
  19. 02 3月, 2015 4 次提交
    • M
      perf probe: Remove bias offset to find probe point by address · 0104fe69
      由 Masami Hiramatsu 提交于 
      Remove bias offset to find probe point by address.

Without this patch, probe points on kernel and executables are shown
correctly, but do not work with libraries:

  # ./perf probe -l
    probe:do_fork        (on do_fork@kernel/fork.c)
    probe_libc:malloc    (on malloc in /usr/lib64/libc-2.17.so)
    probe_perf:strlist__new (on strlist__new@util/strlist.c in /home/mhiramat/ksrc/linux-3/tools/perf/perf)

Removing bias allows it to show it as real place:

  # ./perf probe -l
    probe:do_fork        (on do_fork@kernel/fork.c)
    probe_libc:malloc    (on __libc_malloc@malloc/malloc.c in /usr/lib64/libc-2.17.so)
    probe_perf:strlist__new (on strlist__new@util/strlist.c in /home/mhiramat/ksrc/linux-3/tools/perf/perf)
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naohiro Aota <naota@elisp.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20150302124946.9191.64085.stgit@localhost.localdomainSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      0104fe69
    • M
      perf probe: Warn if given uprobe event accesses memory on older kernel · 79702f61
      由 Masami Hiramatsu 提交于 
      Warn if given uprobe event accesses memory on older kernel.

Until 3.14, uprobe event only supports accessing registers so this warns
to upgrade kernel if uprobe-event returns -EINVAL and an argument of the
event accesses memory ($stack, @+offset, and +|-offs() symtax).

With this patch (on 3.10.0-123.13.2.el7.x86_64);
  -----
  # ./perf probe -x ./perf warn_uprobe_event_compat stack=-0\(%sp\)
  Added new event:
  Failed to write event: Invalid argument
  Please upgrade your kernel to at least 3.14 to have access to feature -0(%sp)
    Error: Failed to add events.
  -----
Suggested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20150228025329.32106.70581.stgit@localhost.localdomainSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      79702f61
    • A
      perf tools: Fix FORK after COMM when synthesizing records for pre-existing threads · 4aa5f4f7
      由 Arnaldo Carvalho de Melo 提交于 
      In this commit:

  commit 363b785f
  Author: Don Zickus <dzickus@redhat.com>
  Date:   Fri Mar 14 10:43:44 2014 -0400

      perf tools: Speed up thread map generation

We ended up emitting PERF_RECORD_FORK events after their corresponding
PERF_RECORD_COMM, so the code below will remove the "existing thread"
and then recreates it, unnecessarily:

  [root@ssdandy ~]# perf probe -x ~/bin/perf -L machine__process_fork_event
  <machine__process_fork_event@/home/acme/git/linux/tools/perf/util/machine.c:0>
      0  int machine__process_fork_event(struct machine *machine, union perf_event *event,
                                        struct perf_sample *sample)
      2  {
      3         struct thread *thread = machine__find_thread(machine,
                                                             event->fork.pid,
                                                             event->fork.tid);
      6         struct thread *parent = machine__findnew_thread(machine,
                                                                event->fork.ppid,
                                                                event->fork.ptid);

                /* if a thread currently exists for the thread id remove it */
                if (thread != NULL)
     12                 machine__remove_thread(machine, thread);

     14         thread = machine__findnew_thread(machine, event->fork.pid,
                                                 event->fork.tid);
     16         if (dump_trace)
     17                 perf_event__fprintf_task(event, stdout);

     19         if (thread == NULL || parent == NULL ||
     20             thread__fork(thread, parent, sample->time) < 0) {
     21                 dump_printf("problem processing PERF_RECORD_FORK, skipping event.\n");
     22                 return -1;
                }

     25         return 0;
     26  }

  [root@ssdandy ~]# perf probe -x ~/bin/perf fork_after_comm=machine__process_fork_event:12
  Added new event:
    probe_perf:fork_after_comm (on machine__process_fork_event:12 in /home/acme/bin/perf)

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

	perf record -e probe_perf:fork_after_comm -aR sleep 1

  [root@ssdandy ~]#

  [root@ssdandy ~]# perf record -g -e probe_perf:* trace -o /tmp/bla
  ^C[ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.021 MB perf.data (30 samples) ]
  Terminated
  [root@ssdandy ~]#

  [root@ssdandy ~]# perf report --no-children --show-total-period --stdio
  # To display the perf.data header info, please use --header/--header-only options.
  #
  # Samples: 30  of event 'probe_perf:fork_after_comm'
  # Event count (approx.): 30
  #
  # Overhead        Period  Command  Shared Object  Symbol
  # ........  ............  .......  .............  ...............................
  #
     100.00%            30  trace    trace          [.] machine__process_fork_event
                |
                ---machine__process_fork_event
                   __event__synthesize_thread.part.2
                   perf_event__synthesize_threads
                   cmd_trace
                   main
                   __libc_start_main

  [root@ssdandy ~]#

  And Looking at 'perf report -D' output we see it:

  0 0 0x8698 [0x30]: PERF_RECORD_COMM: auditd:703/707
  0 0 0x86c8 [0x38]: PERF_RECORD_FORK(703:707):(703:703)

Fix it by more closely mimicking how the kernel generates those records
when a new fork happens, i.e. first a PERF_RECORD_FORK, then a
PERF_RECORD_COMM.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-h0emvymi2t3mw8dlqd6d6z73@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      4aa5f4f7
    • D
      perf tools: Only include tsc file for x86 · ecefde62
      由 David Ahern 提交于 
      The perf_time_to_tsc and tsc_to_perf_time functions are only used for x86.

Make inclusion of tsc.c dependent on x86 as well.
Signed-off-by: NDavid Ahern <david.ahern@oracle.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <david.ahern@oracle.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1424370153-128274-1-git-send-email-david.ahern@oracle.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      ecefde62
  21. 28 2月, 2015 4 次提交