1. 21 1月, 2015 1 次提交
  2. 17 1月, 2015 6 次提交
    • N
      perf tools: Fix segfault for symbol annotation on TUI · 813ccd15
      Namhyung Kim 提交于
      Currently the symbol structure is allocated with symbol_conf.priv_size
      to carry sideband information like annotation, map browser on TUI and
      sort-by-name tree node.  So retrieving these information from symbol
      needs to care about the details of such placement.
      
      However the annotation code just assumes that the symbol is placed after
      the struct annotation.  But actually there's other info between them.
      So accessing those struct will lead to an undefined behavior (usually a
      crash) after they write their info to the same location.
      
      To reproduce the problem, please follow the steps below:
      
        1. run perf report (TUI of course) with -v option
        2. open map browser (by pressing right arrow key for any entry)
        3. search any function (by pressing '/' key and input whatever..)
        4. return to the hist browser (by pressing 'q' or left arrow key)
        5. open annotation window for the same entry (by pressing 'a' key)
      Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Link: http://lkml.kernel.org/r/1421234288-22758-1-git-send-email-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      813ccd15
    • W
      perf test: Fix dwarf unwind using libunwind. · b93b0967
      Wang Nan 提交于
      Perf tool fails to unwind user stack if the event raises in a shared
      object. This patch improves tests/dwarf-unwind.c to demonstrate the
      problem by utilizing commonly used glibc function "bsearch". If perf is
      not statically linked, the testcase will try to unwind a mixed call
      trace.
      
      By debugging libunwind I found that there is a bug in unwind-libunwind:
      it always passes 0 as segbase to libunwind, cause libunwind unable to
      locate debug_frame entry fir first level ip address (I add some more
      debugging output into libunwind to make things clear):
      
                     >_Uarm_dwarf_find_debug_frame: start_ip = 10be98, end_ip = 10c2a4
                     >_Uarm_dwarf_find_debug_frame: found debug_frame table `/lib/libc-2.18.so': segbase=0x0, len=7, gp=0x0, table_data=0x449388
                     >_Uarm_dwarf_search_unwind_table: call lookup:ip = b6cd3bcc, segbase = 0, rel_ip = b6cd3bcc
                     >lookup: e->start_ip_offset = bcf18 (rel_ip = b6cd3bcc)
                     >lookup: e->start_ip_offset = 6d314 (rel_ip = b6cd3bcc)
                     >lookup: e->start_ip_offset = 33d0c (rel_ip = b6cd3bcc)
                      ...
                     >lookup: e->start_ip_offset = 15d0c (rel_ip = b6cd3bcc)
                     >lookup: e->start_ip_offset = 15c40 (rel_ip = b6cd3bcc)
       >_Uarm_dwarf_search_unwind_table: IP b6cd3bcc inside range b6c12000-b6d4c000, but no explicit unwind info found
                      >put_rs_cache: unmasking signals/interrupts and releasing lock
                     >_Uarm_dwarf_step: returning -10
       >_Uarm_step: dwarf_step()=-10
      
      This patch passes map->start as segbase to dwarf_find_debug_frame(), so
      di will be initialized correctly.
      
      In addition, dso and executable are different when setting segbase. This
      patch first check whether the elf is executable, and pass segbase only
      for shared object.
      Signed-off-by: NWang Nan <wangnan0@huawei.com>
      Acked-by: NJiri Olsa <jolsa@kernel.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Li Zefan <lizefan@huawei.com>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      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/1421203007-75799-1-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      b93b0967
    • V
      perf tools: Elide strlcpy warning with uclibc · a83d869f
      Vineet Gupta 提交于
         ----------------->8------------------
        CC       bench/sched-pipe.o
      In file included from builtin-annotate.c:13:0:
      util/cache.h:76:15: warning: redundant redeclaration of 'strlcpy'
      [-Wredundant-decls]
       extern size_t strlcpy(char *dest, const char *src, size_t size);
                     ^
      In file included from util/util.h:55:0,
                       from builtin.h:4,
                       from builtin-annotate.c:8:
      ~/vineetg/arc/gnu/INSTALL_1412-arc-2014.12-rc1/arc-snps-linux-uclibc/sysroot/usr/include/string.h:396:15:
      note: previous declaration of 'strlcpy' was here
       extern size_t strlcpy(char *__restrict dst, const char *__restrict src,
         ----------------->8------------------
      Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
      Cc: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1421156604-30603-3-git-send-email-vgupta@synopsys.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      a83d869f
    • A
      tools: Remove bitops/hweight usage of bits in tools/perf · 25cd480e
      Arnaldo Carvalho de Melo 提交于
      We need to use lib/hweight.c for that, just like we do for lib/rbtree.c,
      so tools need to link hweight.o. For now do it directly, but we need to
      have a tools/lib/lk.a or .so that collects these goodies...
      Reported-by: NJan Beulich <JBeulich@suse.com>
      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: Mike Galbraith <efault@gmx.de>
      Cc: Namhyung Kim <namhyung@kernel.org>
      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-a1e91dx3apzqw5kbdt7ut21s@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      25cd480e
    • N
      perf machine: Fix __machine__findnew_thread() error path · 260d819e
      Namhyung Kim 提交于
      When thread__init_map_groups() fails, a new thread should be removed
      from the rbtree since it's gonna be freed.  Also update last match cache
      only if the function succeeded.
      Reported-by: NDavid Ahern <dsahern@gmail.com>
      Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
      Acked-by: NJiri Olsa <jolsa@kernel.org>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Link: http://lkml.kernel.org/r/1420763892-15535-1-git-send-email-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      260d819e
    • N
      perf probe: Propagate error code when write(2) failed · 7949ba1f
      Namhyung Kim 提交于
      When it failed to write probe commands to the probe_event file in
      debugfs, it needs to propagate the error code properly.  Current code
      blindly uses the return value of the write(2) so it always uses
      -1 (-EPERM) and it might confuse users.
      Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
      Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Link: http://lkml.kernel.org/r/1420886028-15135-4-git-send-email-namhyung@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      7949ba1f
  3. 08 1月, 2015 1 次提交
  4. 02 1月, 2015 2 次提交
    • N
      perf probe: Fix crash in dwarf_getcfi_elf · 4093325f
      Namhyung Kim 提交于
      David reported that perf can segfault when adding an uprobe event like
      this:
      
        $ perf probe -x /lib64/libc-2.14.90.so -a 'malloc  size=%di'
      
        (gdb) bt
        #0  parse_eh_frame_hdr (hdr=0x0, hdr_size=2596, hdr_vaddr=71788,
            ehdr=0x7fffffffd390, eh_frame_vaddr=
            0x7fffffffd378, table_entries=0x8808d8, table_encoding=0x8808e0 "") at
            dwarf_getcfi_elf.c:79
        #1  0x000000385f81615a in getcfi_scn_eh_frame (hdr_vaddr=71788,
            hdr_scn=0x8839b0, shdr=0x7fffffffd2f0, scn=<optimized out>,
            ehdr=0x7fffffffd390, elf=0x882b30) at dwarf_getcfi_elf.c:231
        #2  getcfi_shdr (ehdr=0x7fffffffd390, elf=0x882b30) at dwarf_getcfi_elf.c:283
        #3  dwarf_getcfi_elf (elf=0x882b30) at dwarf_getcfi_elf.c:309
        #4  0x00000000004d5bac in debuginfo__find_probes (pf=0x7fffffffd4f0,
            dbg=Unhandled dwarf expression opcode 0xfa) at util/probe-finder.c:993
        #5  0x00000000004d634a in debuginfo__find_trace_events (dbg=0x880840,
            pev=<optimized out>, tevs=0x880f88, max_tevs=<optimized out>) at
            util/probe-finder.c:1200
        #6  0x00000000004aed6b in try_to_find_probe_trace_events (target=0x881b20
            "/lib64/libpthread-2.14.90.so",
            max_tevs=128, tevs=0x880f88, pev=0x859b30) at util/probe-event.c:482
        #7  convert_to_probe_trace_events (target=0x881b20
            "/lib64/libpthread-2.14.90.so", max_tevs=128, tevs=0x880f88,
            pev=0x859b30) at util/probe-event.c:2356
        #8  add_perf_probe_events (pevs=<optimized out>, npevs=1, max_tevs=128,
            target=0x881b20 "/lib64/libpthread-2.14.90.so", force_add=false) at
            util/probe-event.c:2391
        #9  0x000000000044014f in __cmd_probe (argc=<optimized out>,
            argv=0x7fffffffe2f0, prefix=Unhandled dwarf expression opcode 0xfa) at
            at builtin-probe.c:488
        #10 0x0000000000440313 in cmd_probe (argc=5, argv=0x7fffffffe2f0,
            prefix=<optimized out>) at builtin-probe.c:506
        #11 0x000000000041d133 in run_builtin (p=0x805680, argc=5,
            argv=0x7fffffffe2f0) at perf.c:341
        #12 0x000000000041c8b2 in handle_internal_command (argv=<optimized out>,
            argc=<optimized out>) at perf.c:400
        #13 run_argv (argv=<optimized out>, argcp=<optimized out>) at perf.c:444
        #14 main (argc=5, argv=0x7fffffffe2f0) at perf.c:559
      
      And I found a related commit (5704c8c4fa71 "getcfi_scn_eh_frame: Don't
      crash and burn when .eh_frame bits aren't there.") in elfutils that can
      lead to a unexpected crash like this.  To safely use the function, it
      needs to check the .eh_frame section is a PROGBITS type.
      Reported-by: NDavid Ahern <dsahern@gmail.com>
      Tested-by: NDavid Ahern <dsahern@gmail.com>
      Signed-off-by: NNamhyung Kim <namhyung@kernel.org>
      Acked-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Mark Wielaard <mjw@redhat.com>
      Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Link: http://lkml.kernel.org/r/20141230090533.GH6081@sejongSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      4093325f
    • M
      perf probe: Fix to fall back to find probe point in symbols · 906451b9
      Masami Hiramatsu 提交于
      Fix to fall back to find a probe point in symbols if perf fails to find
      it in debuginfo.
      
      This can happen when the target function is an alias of another
      function. Such alias doesn't have an entry in debuginfo but in symbols.
      
      David Ahern reported this problem in https://lkml.org/lkml/2014/12/29/355
      
      I ensured the problem and deeper investigation discovers it.
       -----
       eu-readelf --debug-dump=info /usr/lib/debug/lib/x86_64-linux-gnu/libc-2.19.so | grep \"malloc\" -A6
                   name                 (strp) "malloc"
                   decl_file            (data1) 25
                   decl_line            (data2) 466
                   prototyped           (flag_present)
                   type                 (ref4) [  81b5]
                   declaration          (flag_present)
       [  8f58]      formal_parameter
       --
                   name                 (strp) "malloc"
                   decl_file            (data1) 23
                   decl_line            (data2) 466
                   prototyped           (flag_present)
                   type                 (ref4) [  9f4a]
                   declaration          (flag_present)
                   sibling              (ref4) [  bb29]
       ...
       -----
      All these entires have no instances (all of them are declarations)
      This is why the perf probe failed to find it in debuginfo.
      
      However, there are some malloc instances in symbols.
       -----
       eu-readelf --symbols /usr/lib/debug/lib/x86_64-linux-gnu/libc-2.19.so | grep malloc$
        1181: 0000000000080700   5332 FUNC    LOCAL  DEFAULT       12 _int_malloc
        4537: 00000000000831d0    339 FUNC    LOCAL  DEFAULT       12 __GI___libc_malloc
        5545: 00000000000831d0    339 FUNC    LOCAL  DEFAULT       12 __malloc
        6063: 00000000000831d0    339 FUNC    GLOBAL DEFAULT       12 malloc
        7302: 00000000000831d0    339 FUNC    GLOBAL DEFAULT       12 __libc_malloc
       -----
      As you an see, malloc and __libc_malloc have same address, and actually
      __libc_malloc has an entry in debuginfo. So you can set up a probe on
      __libc_malloc.
      
      To fix this problem shortly, perf probe simply falls back to find probe
      point(malloc) in symbols if it is not found in debuginfo.
      Reported-by: NDavid Ahern <dsahern@gmail.com>
      Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Acked-by: NNamhyung Kim <namhyung@kernel.org>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: yrl.pp-manager.tt@hitachi.com
      Link: http://lkml.kernel.org/r/20141231062747.2087.80961.stgit@localhost.localdomainSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      906451b9
  5. 23 12月, 2014 2 次提交
  6. 19 12月, 2014 1 次提交
    • W
      perf: Fix building warning on ARM 32 · ac931f87
      Wang Nan 提交于
      Commit 85c116a6 ("perf callchain: Make get_srcline fall back to sym+offset")
      introduces asprintf() call and matches '%ld' to a u64 argument, which is
      incorrect on ARM:
      
         CC       /home/wn/util/srcline.o
       util/srcline.c: In function 'get_srcline':
       util/srcline.c:297:6: error: format '%ld' expects argument of type 'long int', but argument 4 has type 'u64' [-Werror=format]
       cc1: all warnings being treated as errors
       make[1]: *** [/home/wn/util/srcline.o] Error 1
      
      In addition, all users of get_srcline() use u64 addr, and libbfd
      also use 64 bit bfd_vma as address. This patch also fix
      prototype of get_srcline() and addr2line() to use u64 addr
      instead of unsigned long.
      Signed-off-by: NWang Nan <wangnan0@huawei.com>
      Acked-by: NNamhyung Kim <namhyung@kernel.org>
      Cc: <lizefan@huawei.com>
      Cc: <a.p.zijlstra@chello.nl>
      Cc: <paulus@samba.org>
      Cc: <acme@kernel.org>
      Cc: <ak@linux.intel.com>
      Link: http://lkml.kernel.org/r/1418710746-35943-1-git-send-email-wangnan0@huawei.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      ac931f87
  7. 17 12月, 2014 14 次提交
  8. 12 12月, 2014 3 次提交
  9. 11 12月, 2014 1 次提交
  10. 09 12月, 2014 5 次提交
  11. 02 12月, 2014 3 次提交
    • A
      perf callchain: Support handling complete branch stacks as histograms · 8b7bad58
      Andi Kleen 提交于
      Currently branch stacks can be only shown as edge histograms for
      individual branches. I never found this display particularly useful.
      
      This implements an alternative mode that creates histograms over
      complete branch traces, instead of individual branches, similar to how
      normal callgraphs are handled. This is done by putting it in front of
      the normal callgraph and then using the normal callgraph histogram
      infrastructure to unify them.
      
      This way in complex functions we can understand the control flow that
      lead to a particular sample, and may even see some control flow in the
      caller for short functions.
      
      Example (simplified, of course for such simple code this is usually not
      needed), please run this after the whole patchkit is in, as at this
      point in the patch order there is no --branch-history, that will be
      added in a patch after this one:
      
      tcall.c:
      
      volatile a = 10000, b = 100000, c;
      
      __attribute__((noinline)) f2()
      {
      	c = a / b;
      }
      
      __attribute__((noinline)) f1()
      {
      	f2();
      	f2();
      }
      main()
      {
      	int i;
      	for (i = 0; i < 1000000; i++)
      		f1();
      }
      
      % perf record -b -g ./tsrc/tcall
      [ perf record: Woken up 1 times to write data ]
      [ perf record: Captured and wrote 0.044 MB perf.data (~1923 samples) ]
      % perf report --no-children --branch-history
      ...
          54.91%  tcall.c:6  [.] f2                      tcall
                  |
                  |--65.53%-- f2 tcall.c:5
                  |          |
                  |          |--70.83%-- f1 tcall.c:11
                  |          |          f1 tcall.c:10
                  |          |          main tcall.c:18
                  |          |          main tcall.c:18
                  |          |          main tcall.c:17
                  |          |          main tcall.c:17
                  |          |          f1 tcall.c:13
                  |          |          f1 tcall.c:13
                  |          |          f2 tcall.c:7
                  |          |          f2 tcall.c:5
                  |          |          f1 tcall.c:12
                  |          |          f1 tcall.c:12
                  |          |          f2 tcall.c:7
                  |          |          f2 tcall.c:5
                  |          |          f1 tcall.c:11
                  |          |
                  |           --29.17%-- f1 tcall.c:12
                  |                     f1 tcall.c:12
                  |                     f2 tcall.c:7
                  |                     f2 tcall.c:5
                  |                     f1 tcall.c:11
                  |                     f1 tcall.c:10
                  |                     main tcall.c:18
                  |                     main tcall.c:18
                  |                     main tcall.c:17
                  |                     main tcall.c:17
                  |                     f1 tcall.c:13
                  |                     f1 tcall.c:13
                  |                     f2 tcall.c:7
                  |                     f2 tcall.c:5
                  |                     f1 tcall.c:12
      
      The default output is unchanged.
      
      This is only implemented in perf report, no change to record or anywhere
      else.
      
      This adds the basic code to report:
      
      - add a new "branch" option to the -g option parser to enable this mode
      - when the flag is set include the LBR into the callstack in machine.c.
      
      The rest of the history code is unchanged and doesn't know the
      difference between LBR entry and normal call entry.
      
      - detect overlaps with the callchain
      - remove small loop duplicates in the LBR
      
      Current limitations:
      
      - The LBR flags (mispredict etc.) are not shown in the history
      and LBR entries have no special marker.
      - It would be nice if annotate marked the LBR entries somehow
      (e.g. with arrows)
      
      v2: Various fixes.
      v3: Merge further patches into this one. Fix white space.
      v4: Improve manpage. Address review feedback.
      v5: Rename functions. Better error message without -g. Fix crash without
          -b.
      v6: Rebase
      v7: Rebase. Use NO_ENTRY in memset.
      v8: Port to latest tip. Move add_callchain_ip to separate
          patch. Skip initial entries in callchain. Minor cleanups.
      Signed-off-by: NAndi Kleen <ak@linux.intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Link: http://lkml.kernel.org/r/1415844328-4884-3-git-send-email-andi@firstfloor.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      8b7bad58
    • J
      perf stat: Add support for per-pkg counters · 779d0b99
      Jiri Olsa 提交于
      The .per-pkg file indicates that all but one value per socket should be
      discarded. Adding the logic of skipping the rest of the socket once
      first value was read.
      Signed-off-by: NJiri Olsa <jolsa@kernel.org>
      Cc: Andi Kleen <ak@linux.intel.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@kernel.org>
      Cc: Matt Fleming <matt.fleming@intel.com>
      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/1416562275-12404-11-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      779d0b99
    • J
      perf tools: Remove perf_evsel__read interface · a5a7fd76
      Jiri Olsa 提交于
      Removing the perf_evsel__read interfaces because we replaced the only
      user in the stat command code.
      Signed-off-by: NJiri Olsa <jolsa@kernel.org>
      Cc: Andi Kleen <ak@linux.intel.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@kernel.org>
      Cc: Matt Fleming <matt.fleming@intel.com>
      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/1416562275-12404-8-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      a5a7fd76
  12. 29 11月, 2014 1 次提交
    • J
      perf session: Do not fail on processing out of order event · f61ff6c0
      Jiri Olsa 提交于
      Linus reported perf report command being interrupted due to processing
      of 'out of order' event, with following error:
      
        Timestamp below last timeslice flush
        0x5733a8 [0x28]: failed to process type: 3
      
      I could reproduce the issue and in my case it was caused by one CPU
      (mmap) being behind during record and userspace mmap reader seeing the
      data after other CPUs data were already stored.
      
      This is expected under some circumstances because we need to limit the
      number of events that we queue for reordering when we receive a
      PERF_RECORD_FINISHED_ROUND or when we force flush due to memory
      pressure.
      Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: NJiri Olsa <jolsa@kernel.org>
      Acked-by: NIngo Molnar <mingo@kernel.org>
      Cc: Andi Kleen <ak@linux.intel.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@kernel.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Matt Fleming <matt.fleming@intel.com>
      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/1417016371-30249-1-git-send-email-jolsa@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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