1. 18 8月, 2009 1 次提交
    • I
      perf tools: Remove obsolete defines · 1f18345b
      Ingo Molnar 提交于
      The _XOPEN_SOURCE* defines are not really needed on Linux and
      it's not like we'll port this to AIX ;-)
      
      The define also broke the build with gcc 4.4.1:
      
       CC util/trace-event-parse.o
       In file included from util/trace-event-parse.c:32:
       util/util.h:43:1: error: "_XOPEN_SOURCE" redefined
      
      So remove them.
      
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <new-submission>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      1f18345b
  2. 17 8月, 2009 4 次提交
  3. 16 8月, 2009 1 次提交
    • I
      perf: Enable more compiler warnings · 83a0944f
      Ingo Molnar 提交于
      Related to a shadowed variable bug fix Valdis Kletnieks noticed
      that perf does not get built with -Wshadow, which could have
      helped us avoid the bug.
      
      So enable -Wshadow and also enable the following warnings on
      perf builds, in addition to the already enabled -Wall -Wextra
      -std=gnu99 warnings:
      
       -Wcast-align
       -Wformat=2
       -Wshadow
       -Winit-self
       -Wpacked
       -Wredundant-decls
       -Wstack-protector
       -Wstrict-aliasing=3
       -Wswitch-default
       -Wswitch-enum
       -Wno-system-headers
       -Wundef
       -Wvolatile-register-var
       -Wwrite-strings
       -Wbad-function-cast
       -Wmissing-declarations
       -Wmissing-prototypes
       -Wnested-externs
       -Wold-style-definition
       -Wstrict-prototypes
       -Wdeclaration-after-statement
      
      And change/fix the perf code to build cleanly under GCC 4.3.2.
      
      The list of warnings enablement is rather arbitrary: it's based
      on my (quick) reading of the GCC manpages and trying them on
      perf.
      
      I categorized the warnings based on individually enabling them
      and looking whether they trigger something in the perf build.
      If i liked those warnings (i.e. if they trigger for something
      that arguably could be improved) i enabled the warning.
      
      If the warnings seemed to come from language laywers spamming
      the build with tons of nuisance warnings i generally kept them
      off. Most of the sign conversion related warnings were in
      this category. (A second patch enabling some of the sign
      warnings might be welcome - sign bugs can be nasty.)
      
      I also kept warnings that seem to make sense from their manpage
      description and which produced no actual warnings on our code
      base. These warnings might still be turned off if they end up
      being a nuisance.
      
      I also left out a few warnings that are not supported in older
      compilers.
      
      [ Note that these changes might break the build on older
        compilers i did not test, or on non-x86 architectures that
        produce different warnings, so more testing would be welcome. ]
      
      Reported-by: Valdis.Kletnieks@vt.edu
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <new-submission>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      83a0944f
  4. 15 8月, 2009 2 次提交
  5. 13 8月, 2009 1 次提交
    • F
      perf tools: Add a per tracepoint counter attribute to get raw sample · 3a9f131f
      Frederic Weisbecker 提交于
      Add a new flag field while opening a tracepoint perf counter:
      
      	-e tracepoint_subsystem:tracepoint_name:flags
      
      This is intended to be generic although for now it only supports the
      r[e[c[o[r[d]]]]] flag:
      
      	./perf record -e workqueue:workqueue_insertion:record
      	./perf record -e workqueue:workqueue_insertion:r
      
      will have the same effect: enabling the raw samples record for
      the given tracepoint counter.
      
      In the future, we may want to support further flags, separated
      by commas.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Mike Galbraith <efault@gmx.de>
      LKML-Reference: <1250152039-7284-1-git-send-email-fweisbec@gmail.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      3a9f131f
  6. 12 8月, 2009 5 次提交
    • A
      perf tools: Fix dso__new handle() to handle deleted DSOs · 1340e6bb
      Arnaldo Carvalho de Melo 提交于
      It is better than showing the map addr, this way at least we
      know that we can't get the symtabs because the DSO was deleted
      (system update) while an app still used such DSO.
      
      Yeah, don't do that, but if you do, you'll figure it out
      quicker this way.
      
      [acme@doppio linux-2.6-tip]$ perf report | head -15
       # Samples: 3796
       #
       # Overhead  Command                                                        Shared Object  Symbol
       # ........  .......  ...................................................................  ......
       #
          23.55%   pidgin  /lib64/libglib-2.0.so.0.2000.4.#prelink#.Pd98lu (deleted)            [.] 0x00000000038844
          21.55%   pidgin  /lib64/libpthread-2.10.1.so.#prelink#.AFwK8Q (deleted)               [.] 0x0000000000a42d
          10.85%   pidgin  [kernel]                                                             [.] vread_hpet
           7.85%   pidgin  /lib64/libgobject-2.0.so.0.2000.4.#prelink#.o1vpU7 (deleted)         [.] 0x00000000014de8
           3.35%   pidgin  /lib64/libc-2.10.1.so (deleted)                                      [.] 0x0000000007a875
           3.19%   pidgin  /lib64/libdbus-1.so.3.4.0.#prelink#.6mwgZP (deleted)                 [.] 0x0000000001d254
           3.06%   pidgin  /usr/lib64/libgtk-x11-2.0.so.0.1600.5.#prelink#.511hAl (deleted)     [.] 0x000000002334e7
           2.90%   pidgin  /usr/lib64/libgdk-x11-2.0.so.0.1600.5.#prelink#.5qlMo1 (deleted)     [.] 0x00000000037b2d
           1.84%   pidgin  [kernel]                                                             [k] do_sys_poll
           1.45%   pidgin  /usr/lib64/libX11.so.6.2.0.#prelink#.iR59Rx (deleted)                [.] 0x0000000004c751
      [acme@doppio linux-2.6-tip]$
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Luis Claudio R. Gonçalves <lclaudio@redhat.com>
      Cc: Clark Williams <williams@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Frédéric Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <20090811200436.GA3478@ghostprotocols.net>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      1340e6bb
    • A
      perf tools: Fix fallback to cplus_demangle() when bfd_demangle() is not available · 247648e3
      Arnaldo Carvalho de Melo 提交于
      In old binutils we can't access bfd_demangle(), use
      cplus_demangle() just like oprofile.
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Luis Claudio R. Gonçalves <lclaudio@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Frédéric Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <20090811192211.GG18061@ghostprotocols.net>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      247648e3
    • F
      perf tools: Factorize the map helpers · 66e274f3
      Frederic Weisbecker 提交于
      Factorize the dso mapping helpers into a single purpose common file
      "util/map.c"
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Brice Goglin <Brice.Goglin@inria.fr>
      66e274f3
    • F
      perf tools: Factorize the event structure definitions in a single file · 1fe2c106
      Frederic Weisbecker 提交于
      Factorize the multiple definition of the events structures into a
      single util/event.h file.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Brice Goglin <Brice.Goglin@inria.fr>
      1fe2c106
    • F
      perf tools: Factorize high level dso helpers · cd84c2ac
      Frederic Weisbecker 提交于
      Factorize multiple definitions of high level dso helpers into the
      symbol source file.
      
      The side effect is a general export of the verbose and eprintf
      debugging helpers into a new file dedicated to debugging purposes.
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Brice Goglin <Brice.Goglin@inria.fr>
      cd84c2ac
  7. 10 8月, 2009 1 次提交
  8. 09 8月, 2009 10 次提交
  9. 07 8月, 2009 1 次提交
    • A
      perf symbol: Fix symbol parsing in certain cases: use the build-id as a symlink · 4d1e00a8
      Arnaldo Carvalho de Melo 提交于
      In some cases distros have binaries and debuginfo in weird places:
      
      [root@doppio tuna]# ls -la /usr/lib64/{xulrunner-1.9.1/xulrunner-stub,firefox-3.5.2/firefox}
      -rwxr-xr-x 1 root root 90024 2009-08-03 19:45 /usr/lib64/firefox-3.5.2/firefox
      -rwxr-xr-x 1 root root 90024 2009-08-03 18:23 /usr/lib64/xulrunner-1.9.1/xulrunner-stub
      [root@doppio tuna]# sha1sum /usr/lib64/{xulrunner-1.9.1/xulrunner-stub,firefox-3.5.2/firefox}
      19a858077d263d5de22c9c5da250d3e4396ae739  /usr/lib64/xulrunner-1.9.1/xulrunner-stub
      19a858077d263d5de22c9c5da250d3e4396ae739  /usr/lib64/firefox-3.5.2/firefox
      [root@doppio tuna]# rpm -qf /usr/lib64/{xulrunner-1.9.1/xulrunner-stub,firefox-3.5.2/firefox}
      xulrunner-1.9.1.2-1.fc11.x86_64
      firefox-3.5.2-2.fc11.x86_64
      [root@doppio tuna]# ls -la /usr/lib/debug/{usr/lib64/xulrunner-1.9.1/xulrunner-stub,usr/lib64/firefox-3.5.2/firefox}.debug
      ls: cannot access /usr/lib/debug/usr/lib64/firefox-3.5.2/firefox.debug: No such file or directory
      -rwxr-xr-x 1 root root 403608 2009-08-03 18:22 /usr/lib/debug/usr/lib64/xulrunner-1.9.1/xulrunner-stub.debug
      
      Seemingly we don't have a .symtab when we actually can find it
      if we use the .note.gnu.build-id ELF section put in place by
      some distros. Use it and find the symbols we need.
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Acked-by: NPeter Zijlstra <peterz@infradead.org>
      LKML-Reference: <new-submission>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      4d1e00a8
  10. 05 8月, 2009 1 次提交
    • P
      perf: Auto-detect libbfd · 2cdbc46d
      Peter Zijlstra 提交于
      Since the C++ demangling isn't needed for everybody and
      bfd/iberty aren't widely/easily available on all machines, make
      it optional.
      
      It also allows you to forcefully disable demangling by using
      NO_DEMANGLE=1 and otherwise tries to detect libbfd/libiberty
      combinations that result in a compiling demangler.
      Reported-by: NJens Axboe <jens.axboe@oracle.com>
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Kyle McMartin <kyle@mcmartin.ca>
      LKML-Reference: <20090801082048.GX12579@kernel.dk>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      2cdbc46d
  11. 04 8月, 2009 1 次提交
  12. 02 8月, 2009 1 次提交
    • S
      perf tools: Fix faulty check · 9b30a26b
      Stoyan Gaydarov 提交于
      This patch fixes a spelling error that has resulted from copy
      and pasting. The location of the error was found using a
      semantic patch but the semantic patch was not trying to find
      these errors. After looking things over it seemed logical that
      this change was needed. Please review it and then include the
      patch if it is in fact the correct change.
      Signed-off-by: NStoyan Gaydarov <sgayda2@uiuc.edu>
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      LKML-Reference: <1248949529-20891-1-git-send-email-sgayda2@uiuc.edu>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      9b30a26b
  13. 23 7月, 2009 5 次提交
    • M
      perf_counter tools: Fix vmlinux symbol generation breakage · d20ff6bd
      Mike Galbraith 提交于
      vmlinux meets the criteria for symbol adjustment, which breaks vmlinux generated symbols.
      Fix this by exempting vmlinux.  This is a bit fragile in that someone could change the
      kernel dso's name, but currently that name is also hardwired.
      Signed-off-by: NMike Galbraith <efault@gmx.de>
      Cc: Ingo Molnar <mingo@elte.hu>
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      LKML-Reference: <1248091298.18702.18.camel@marge.simson.net>
      d20ff6bd
    • J
      perf_counter: Detect debugfs location · 5beeded1
      Jason Baron 提交于
      If "/sys/kernel/debug" is not a debugfs mount point, search for the debugfs
      filesystem in /proc/mounts, but also allows the user to specify
      '--debugfs-dir=blah' or set the environment variable: 'PERF_DEBUGFS_DIR'
      Signed-off-by: NJason Baron <jbaron@redhat.com>
      [ also made it probe "/debug" by default ]
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      LKML-Reference: <20090721181629.GA3094@redhat.com>
      5beeded1
    • J
      perf_counter: Add tracepoint support to perf list, perf stat · f6bdafef
      Jason Baron 提交于
      Add support to 'perf list' and 'perf stat' for kernel tracepoints. The
      implementation creates a 'for_each_subsystem' and 'for_each_event' for
      easy iteration over the tracepoints.
      Signed-off-by: NJason Baron <jbaron@redhat.com>
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      LKML-Reference: <426129bf9fcc8ee63bb094cf736e7316a7dcd77a.1248190728.git.jbaron@redhat.com>
      f6bdafef
    • A
      perf symbol: C++ demangling · 28ac909b
      Arnaldo Carvalho de Melo 提交于
      [acme@doppio ~]$ perf report -s comm,dso,symbol -C firefox -d /usr/lib64/xulrunner-1.9.1/libxul.so | grep :: | head
           2.21%  [.] nsDeque::Push(void*)
           1.78%  [.] GraphWalker::DoWalk(nsDeque&)
           1.30%  [.] GCGraphBuilder::AddNode(void*, nsCycleCollectionParticipant*)
           1.27%  [.] XPCWrappedNative::CallMethod(XPCCallContext&, XPCWrappedNative::CallMode)
           1.18%  [.] imgContainer::DrawFrameTo(gfxIImageFrame*, gfxIImageFrame*, nsRect&)
           1.13%  [.] nsDeque::PopFront()
           1.11%  [.] nsGlobalWindow::RunTimeout(nsTimeout*)
           0.97%  [.] nsXPConnect::Traverse(void*, nsCycleCollectionTraversalCallback&)
           0.95%  [.] nsJSEventListener::cycleCollection::Traverse(void*, nsCycleCollectionTraversalCallback&)
           0.95%  [.] nsCOMPtr_base::~nsCOMPtr_base()
      [acme@doppio ~]$
      
      Cc: Pekka Enberg <penberg@cs.helsinki.fi>
      Cc: Vegard Nossum <vegard.nossum@gmail.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Frédéric Weisbecker <fweisbec@gmail.com>
      Suggested-by: NClark Williams <williams@redhat.com>
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      LKML-Reference: <20090720171412.GB10410@ghostprotocols.net>
      28ac909b
    • A
      perf: avoid structure size confusion by using a fixed size · dfe5a504
      Arjan van de Ven 提交于
      for some reason, this structure gets compiled as 36 bytes in some files
      (the ones that alloacte it) but 40 bytes in others (the ones that use it).
      The cause is an off_t type that gets a different size in different
      compilation units for some yet-to-be-explained reason.
      
      But the effect is disasterous; the size/offset members of the struct
      are at different offsets, and result in mostly complete garbage.
      The parser in perf is so robust that this all gets hidden, and after
      skipping an certain amount of samples, it recovers.... so this bug
      is not normally noticed.
      
      .... except when you want every sample to be exact.
      
      Fix this by just using an explicitly sized type.
      Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
      Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
      LKML-Reference: <4A655917.9080504@linux.intel.com>
      dfe5a504
  14. 13 7月, 2009 1 次提交
  15. 12 7月, 2009 2 次提交
    • A
      perf_counter tools: PLT info is stripped in -debuginfo packages · a25e46c4
      Arnaldo Carvalho de Melo 提交于
      So we need to get the richer .symtab from the debuginfo
      packages but the PLT info from the original DSO where we have
      just the leaner .dynsym symtab.
      
      Example:
      
      | [acme@doppio pahole]$ perf report --sort comm,dso,symbol > before
      | [acme@doppio pahole]$ perf report --sort comm,dso,symbol > after
      | [acme@doppio pahole]$ diff -U1 before after
      | --- before	2009-07-11 11:04:22.688595741 -0300
      | +++ after	2009-07-11 11:04:33.380595676 -0300
      | @@ -80,3 +80,2 @@
      |       0.07%  pahole ./build/pahole              [.] pahole_stealer
      | -     0.06%  pahole /usr/lib64/libdw-0.141.so   [.] 0x00000000007140
      |       0.06%  pahole /usr/lib64/libdw-0.141.so   [.] __libdw_getabbrev
      | @@ -91,2 +90,3 @@
      |       0.06%  pahole [kernel]                    [k] free_hot_cold_page
      | +     0.06%  pahole /usr/lib64/libdw-0.141.so   [.] tfind@plt
      |       0.05%  pahole ./build/libdwarves.so.1.0.0 [.] ftype__add_parameter
      | @@ -242,2 +242,3 @@
      |       0.01%  pahole [kernel]                    [k] account_group_user_time
      | +     0.01%  pahole /usr/lib64/libdw-0.141.so   [.] strlen@plt
      |       0.01%  pahole ./build/pahole              [.] strcmp@plt
      | [acme@doppio pahole]$
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      LKML-Reference: <1247325517-12272-4-git-send-email-acme@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      a25e46c4
    • A
      strlist: Introduce strlist__entry and strlist__nr_entries methods · 27d0fd41
      Arnaldo Carvalho de Melo 提交于
      The strlist__entry method allows accessing strlists like an
      array, will be used in the 'perf report' to access the first
      entry.
      
      We now keep the nr_entries so that we can check if we have just
      one entry, will be used in 'perf report' to improve the output
      by showing just at the top when we have just, say, one DSO.
      
      While at it use nr_entries to optimize strlist__is_empty by not
      using the far more costly rb_first based implementation.
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      LKML-Reference: <1247325517-12272-2-git-send-email-acme@redhat.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      27d0fd41
  16. 11 7月, 2009 1 次提交
    • A
      perf report: Adjust column width to the values sampled · 52d422de
      Arnaldo Carvalho de Melo 提交于
      Auto-adjust column width of perf report output to the
      longest occuring string length.
      
      Example:
      
      [acme@doppio pahole]$  perf report --sort comm,dso,symbol | head -13
      
          12.79%   pahole  /usr/lib64/libdw-0.141.so    [.] __libdw_find_attr
           8.90%   pahole  /lib64/libc-2.10.1.so        [.] _int_malloc
           8.68%   pahole  /usr/lib64/libdw-0.141.so    [.] __libdw_form_val_len
           8.15%   pahole  /lib64/libc-2.10.1.so        [.] __GI_strcmp
           6.80%   pahole  /lib64/libc-2.10.1.so        [.] __tsearch
           5.54%   pahole  ./build/libdwarves.so.1.0.0  [.] tag__recode_dwarf_type
      [acme@doppio pahole]$
      
      [acme@doppio pahole]$  perf report --sort comm,dso,symbol -d /lib64/libc-2.10.1.so | head -10
      
          21.92%   pahole  /lib64/libc-2.10.1.so  [.] _int_malloc
          20.08%   pahole  /lib64/libc-2.10.1.so  [.] __GI_strcmp
          16.75%   pahole  /lib64/libc-2.10.1.so  [.] __tsearch
      [acme@doppio pahole]$
      
      Also add these extra options to control the new behaviour:
      
        -w, --field-width
      
      Force each column width to the provided list, for large terminal
      readability.
      
        -t, --field-separator:
      
      Use a special separator character and don't pad with spaces, replacing
      all occurances of this separator in symbol names (and other output) with
      a '.' character, that thus it's the only non valid separator.
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Paul Mackerras <paulus@samba.org>
      LKML-Reference: <20090711014728.GH3452@ghostprotocols.net>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      52d422de
  17. 10 7月, 2009 1 次提交
  18. 05 7月, 2009 1 次提交
    • F
      perf report: Add "Fractal" mode output - support callchains with relative overhead rate · 805d127d
      Frederic Weisbecker 提交于
      The current callchain displays the overhead rates as absolute:
      relative to the total overhead.
      
      This patch provides relative overhead percentage, in which each
      branch of the callchain tree is a independant instrumentated object.
      
      This provides a 'fractal' view of the call-chain profile: each
      sub-graph looks like a profile in itself - relative to its parent.
      
      You can produce such output by using the "fractal" mode
      that you can abbreviate via f, fr, fra, frac, etc...
      
      ./perf report -s sym -c fractal
      
      Example:
      
           8.46%  [k] copy_user_generic_string
                      |
                      |--52.01%-- generic_file_aio_read
                      |          do_sync_read
                      |          vfs_read
                      |          |
                      |          |--97.20%-- sys_pread64
                      |          |          system_call_fastpath
                      |          |          pread64
                      |          |
                      |           --2.81%-- sys_read
                      |                     system_call_fastpath
                      |                     __read
                      |
                      |--39.85%-- generic_file_buffered_write
                      |          __generic_file_aio_write_nolock
                      |          generic_file_aio_write
                      |          do_sync_write
                      |          reiserfs_file_write
                      |          vfs_write
                      |          |
                      |          |--97.05%-- sys_pwrite64
                      |          |          system_call_fastpath
                      |          |          __pwrite64
                      |          |
                      |           --2.95%-- sys_write
                      |                     system_call_fastpath
                      |                     __write_nocancel
      [...]
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Mike Galbraith <efault@gmx.de>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Anton Blanchard <anton@samba.org>
      Cc: Jens Axboe <jens.axboe@oracle.com>
      Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
      LKML-Reference: <1246772361-9960-5-git-send-email-fweisbec@gmail.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      805d127d