1. 19 5月, 2018 2 次提交
  2. 18 5月, 2018 1 次提交
    • S
      perf script: Show virtual addresses instead of offsets · 19610184
      Sandipan Das 提交于
      When perf data is recorded with the call-graph option enabled, the
      callchain shown by perf script shows the binary offsets of the symbols
      as the ip. This is incorrect for kernel symbols as the ip values are
      always off by a fixed offset depending on the architecture. If the
      offsets from the start of the symbols are printed, they are also
      incorrect for both kernel and userspace symbols.
      
      Without the call-graph option, the callchain shows the virtual addresses
      of the symbols rather than their binary offsets. The offsets printed in
      this case are also correct.
      
      This fixes the inconsistency in perf script's output.
      
      This can be verified on a powerpc64le system running Fedora 27 as
      follows:
      
        # cat /proc/kallsyms | grep sys_write
        ...
        c0000000004025a0 T sys_write
        c0000000004025a0 T __se_sys_write
        ...
      
        # perf probe -a sys_write
      
      Before applying this patch:
      
        # perf record -e probe:sys_write -g ~/test
        # perf script -F ip,sym,symoff
      
                          4125b0 sys_write+0x8000000000008010
                           1b9e0 system_call+0x8000000000008058
                          118234 __GI___libc_write+0xffff0000f52c0024
                           92c74 _IO_file_write@@GLIBC_2.17+0xffff0000f52c0044
                        5afbfd8a [unknown]
                           91a60 new_do_write+0xffff0000f52c0090
                           94638 _IO_do_write@@GLIBC_2.17+0xffff0000f52c0038
                           94bbc _IO_file_overflow@@GLIBC_2.17+0xffff0000f52c014c
                           95a24 __overflow+0xffff0000f52c0064
                           84548 _IO_puts+0xffff0000f52c0218
                             440 main+0xffffffffe0000020
                           236a0 generic_start_main.isra.0+0xffff0000f52c0140
                           23898 __libc_start_main+0xffff0000f52c00b8
                               0 [unknown]
        ...
      
        # perf record -e probe:sys_write ~/test
        # perf script -F ip,sym,symoff
      
        c0000000004025b0 sys_write+0x10
        ...
      
      After applying this patch:
      
        # perf record -e probe:sys_write -g ~/test
        # perf script -F ip,sym,symoff
      
                c0000000004025b0 sys_write+0x10
                c00000000000b9e0 system_call+0x58
                    7fffb70d8234 __GI___libc_write+0x24
                    7fffb7052c74 _IO_file_write@@GLIBC_2.17+0x44
                        5afc1818 [unknown]
                    7fffb7051a60 new_do_write+0x90
                    7fffb7054638 _IO_do_write@@GLIBC_2.17+0x38
                    7fffb7054bbc _IO_file_overflow@@GLIBC_2.17+0x14c
                    7fffb7055a24 __overflow+0x64
                    7fffb7044548 _IO_puts+0x218
                        10000440 main+0x20
                    7fffb6fe36a0 generic_start_main.isra.0+0x140
                    7fffb6fe3898 __libc_start_main+0xb8
                               0 [unknown]
        ...
      
        # perf record -e probe:sys_write ~/test
        # perf script -F ip,sym,symoff
      
        c0000000004025b0 sys_write+0x10
        ...
      Signed-off-by: NSandipan Das <sandipan@linux.vnet.ibm.com>
      Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
      Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
      Link: http://lkml.kernel.org/r/20180517063326.6319-1-sandipan@linux.vnet.ibm.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      19610184
  3. 30 4月, 2018 1 次提交
  4. 27 4月, 2018 9 次提交
  5. 23 4月, 2018 1 次提交
  6. 17 3月, 2018 1 次提交
  7. 08 3月, 2018 1 次提交
  8. 19 2月, 2018 1 次提交
  9. 17 2月, 2018 5 次提交
  10. 08 1月, 2018 1 次提交
    • J
      perf report: Fix a wrong offset issue when using /proc/kcore · 935f5a9d
      Jin Yao 提交于
      When a valid vmlinux is not found, 'perf report' falls back to look at
      /proc/kcore. In this case, it will report the impossible large offset.
      
      For example:
      
        # perf record -b -e cycles:k find /etc/ > /dev/null
        # perf report --stdio --branch-history
      
          22.77%  _vm_normal_page+18446603336221188162
                  |
                  ---page_remove_rmap +18446603336221188324
                     page_remove_rmap +18446603336221188487 (cycles:5)
                     unlock_page_memcg +18446603336221188096
                     page_remove_rmap +18446603336221188327 (cycles:1)
      
      The issue is the value which is passed to parameter 'addr' in
      __get_srcline() is the objdump address. It's not correct if we calculate
      the offset by using 'addr - sym->start'.
      
      This patch creates a new parameter 'ip' in __get_srcline(). It is not
      converted to objdump address.
      
      With this patch, the perf report output is:
      
          22.77%  _vm_normal_page+66
                  |
                  ---page_remove_rmap +228
                     page_remove_rmap +391 (cycles:5)
                     unlock_page_memcg +0
                     page_remove_rmap +231 (cycles:1)
                     page_remove_rmap +236
      
      Committer testing:
      
      Make sure you get any valid vmlinux out of the way, using '-v' on the
      'perf report' case and deleting it from places where perf searches them,
      like your kernel build dir and the build-id cache, in ~/.debug/.
      Reported-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Signed-off-by: NJin Yao <yao.jin@linux.intel.com>
      Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Kan Liang <kan.liang@intel.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1514564812-17344-1-git-send-email-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      935f5a9d
  11. 29 11月, 2017 1 次提交
    • A
      perf machine: Guard against NULL in machine__exit() · 4a2233b1
      Arnaldo Carvalho de Melo 提交于
      A recent fix for 'perf trace' introduced a bug where
      machine__exit(trace->host) could be called while trace->host was still
      NULL, so make this more robust by guarding against NULL, just like
      free() does.
      
      The problem happens, for instance, when !root users try to run 'perf
      trace':
      
        [acme@jouet linux]$ trace
        Error:	No permissions to read /sys/kernel/debug/tracing/events/raw_syscalls/sys_(enter|exit)
        Hint:	Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing'
      
        perf: Segmentation fault
        Obtained 7 stack frames.
        [0x4f1b2e]
        /lib64/libc.so.6(+0x3671f) [0x7f43a1dd971f]
        [0x4f3fec]
        [0x47468b]
        [0x42a2db]
        /lib64/libc.so.6(__libc_start_main+0xe9) [0x7f43a1dc3509]
        [0x42a6c9]
        Segmentation fault (core dumped)
        [acme@jouet linux]$
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Andrei Vagin <avagin@openvz.org>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Vasily Averin <vvs@virtuozzo.com>
      Cc: Wang Nan <wangnan0@huawei.com>
      Fixes: 33974a41 ("perf trace: Call machine__exit() at exit")
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      4a2233b1
  12. 17 11月, 2017 2 次提交
    • J
      perf callchain: Reset cursor arg instead of callchain_cursor · 914eb9ca
      Jiri Olsa 提交于
      We already pass cursor into thread__resolve_callchain function, so
      there's no point in resetting the global instance.
      Signed-off-by: NJiri Olsa <jolsa@kernel.org>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Wang Nan <wangnan0@huawei.com>
      Link: http://lkml.kernel.org/n/tip-puk015qvuppao9m1xtdy9v7j@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      914eb9ca
    • A
      perf machine: Guard against NULL in machine__exit() · 19993b82
      Arnaldo Carvalho de Melo 提交于
      A recent fix for 'perf trace' introduced a bug where
      machine__exit(trace->host) could be called while trace->host was still
      NULL, so make this more robust by guarding against NULL, just like
      free() does.
      
      The problem happens, for instance, when !root users try to run 'perf
      trace':
      
        [acme@jouet linux]$ trace
        Error:	No permissions to read /sys/kernel/debug/tracing/events/raw_syscalls/sys_(enter|exit)
        Hint:	Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing'
      
        perf: Segmentation fault
        Obtained 7 stack frames.
        [0x4f1b2e]
        /lib64/libc.so.6(+0x3671f) [0x7f43a1dd971f]
        [0x4f3fec]
        [0x47468b]
        [0x42a2db]
        /lib64/libc.so.6(__libc_start_main+0xe9) [0x7f43a1dc3509]
        [0x42a6c9]
        Segmentation fault (core dumped)
        [acme@jouet linux]$
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Andrei Vagin <avagin@openvz.org>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Vasily Averin <vvs@virtuozzo.com>
      Cc: Wang Nan <wangnan0@huawei.com>
      Fixes: 33974a41 ("perf trace: Call machine__exit() at exit")
      Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      19993b82
  13. 02 11月, 2017 1 次提交
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman 提交于
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard license headers were used, and references to license
      had to be inferred by heuristics based on keywords.
      
      The analysis to determine which SPDX License Identifier to be applied to
      a file was done in a spreadsheet of side by side results from of the
      output of two independent scanners (ScanCode & Windriver) producing SPDX
      tag:value files created by Philippe Ombredanne.  Philippe prepared the
      base worksheet, and did an initial spot review of a few 1000 files.
      
      The 4.13 kernel was the starting point of the analysis with 60,537 files
      assessed.  Kate Stewart did a file by file comparison of the scanner
      results in the spreadsheet to determine which SPDX license identifier(s)
      to be applied to the file. She confirmed any determination that was not
      immediately clear with lawyers working with the Linux Foundation.
      
      Criteria used to select files for SPDX license identifier tagging was:
       - Files considered eligible had to be source code files.
       - Make and config files were included as candidates if they contained >5
         lines of source
       - File already had some variant of a license header in it (even if <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  14. 25 10月, 2017 2 次提交
    • M
      perf report: Cache srclines for callchain nodes · 21ac9d54
      Milian Wolff 提交于
      On one hand this ensures that the memory is properly freed when the DSO
      gets freed. On the other hand this significantly speeds up the
      processing of the callchain nodes when lots of srclines are requested.
      For one of my data files e.g.:
      
      Before:
      
       Performance counter stats for 'perf report -s srcline -g srcline --stdio':
      
            52496.495043      task-clock (msec)         #    0.999 CPUs utilized
                     634      context-switches          #    0.012 K/sec
                       2      cpu-migrations            #    0.000 K/sec
                 191,561      page-faults               #    0.004 M/sec
         165,074,498,235      cycles                    #    3.144 GHz
         334,170,832,408      instructions              #    2.02  insn per cycle
          90,220,029,745      branches                  # 1718.591 M/sec
             654,525,177      branch-misses             #    0.73% of all branches
      
            52.533273822 seconds time elapsedProcessed 236605 events and lost 40 chunks!
      
      After:
      
       Performance counter stats for 'perf report -s srcline -g srcline --stdio':
      
            22606.323706      task-clock (msec)         #    1.000 CPUs utilized
                      31      context-switches          #    0.001 K/sec
                       0      cpu-migrations            #    0.000 K/sec
                 185,471      page-faults               #    0.008 M/sec
          71,188,113,681      cycles                    #    3.149 GHz
         133,204,943,083      instructions              #    1.87  insn per cycle
          34,886,384,979      branches                  # 1543.214 M/sec
             278,214,495      branch-misses             #    0.80% of all branches
      
            22.609857253 seconds time elapsed
      
      Note that the difference is only this large when `--inline` is not
      passed. In such situations, we would use the inliner cache and thus do
      not run this code path that often.
      
      I think that this cache should actually be used in other places, too.
      When looking at the valgrind leak report for perf report, we see tons of
      srclines being leaked, most notably from calls to
      hist_entry__get_srcline. The problem is that get_srcline has many
      different formatting options (show_sym, show_addr, potentially even
      unwind_inlines when calling __get_srcline directly). As such, the
      srcline cannot easily be cached for all calls, or we'd have to add
      caches for all formatting combinations (6 so far). An alternative would
      be to remove the formatting options and handle that on a different level
      - i.e. print the sym/addr on demand wherever we actually output
      something. And the unwind_inlines could be moved into a separate
      function that does not return the srcline.
      Signed-off-by: NMilian Wolff <milian.wolff@kdab.com>
      Reviewed-by: NAndi Kleen <ak@linux.intel.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Jin Yao <yao.jin@linux.intel.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/20171019113836.5548-4-milian.wolff@kdab.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      21ac9d54
    • M
      perf report: Cache failed lookups of inlined frames · b38775cf
      Milian Wolff 提交于
      When no inlined frames could be found for a given address, we did not
      store this information anywhere. That means we potentially do the costly
      inliner lookup repeatedly for cases where we know it can never succeed.
      
      This patch makes dso__parse_addr_inlines always return a valid
      inline_node. It will be empty when no inliners are found. This enables
      us to cache the empty list in the DSO, thereby improving the performance
      when many addresses fail to find the inliners.
      
      For my trivial example, the performance impact is already quite
      significant:
      
      Before:
      
      ~~~~~
       Performance counter stats for 'perf report --stdio --inline -g srcline -s srcline' (5 runs):
      
              594.804032      task-clock (msec)         #    0.998 CPUs utilized            ( +-  0.07% )
                      53      context-switches          #    0.089 K/sec                    ( +-  4.09% )
                       0      cpu-migrations            #    0.000 K/sec                    ( +-100.00% )
                   5,687      page-faults               #    0.010 M/sec                    ( +-  0.02% )
           2,300,918,213      cycles                    #    3.868 GHz                      ( +-  0.09% )
           4,395,839,080      instructions              #    1.91  insn per cycle           ( +-  0.00% )
             939,177,205      branches                  # 1578.969 M/sec                    ( +-  0.00% )
              11,824,633      branch-misses             #    1.26% of all branches          ( +-  0.10% )
      
             0.596246531 seconds time elapsed                                          ( +-  0.07% )
      ~~~~~
      
      After:
      
      ~~~~~
       Performance counter stats for 'perf report --stdio --inline -g srcline -s srcline' (5 runs):
      
              113.111405      task-clock (msec)         #    0.990 CPUs utilized            ( +-  0.89% )
                      29      context-switches          #    0.255 K/sec                    ( +- 54.25% )
                       0      cpu-migrations            #    0.000 K/sec
                   5,380      page-faults               #    0.048 M/sec                    ( +-  0.01% )
             432,378,779      cycles                    #    3.823 GHz                      ( +-  0.75% )
             670,057,633      instructions              #    1.55  insn per cycle           ( +-  0.01% )
             141,001,247      branches                  # 1246.570 M/sec                    ( +-  0.01% )
               2,346,845      branch-misses             #    1.66% of all branches          ( +-  0.19% )
      
             0.114222393 seconds time elapsed                                          ( +-  1.19% )
      ~~~~~
      Signed-off-by: NMilian Wolff <milian.wolff@kdab.com>
      Reviewed-by: NAndi Kleen <ak@linux.intel.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Jin Yao <yao.jin@linux.intel.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/20171019113836.5548-3-milian.wolff@kdab.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      b38775cf
  15. 24 10月, 2017 2 次提交
  16. 03 10月, 2017 1 次提交
    • K
      perf top: Implement multithreading for perf_event__synthesize_threads · 340b47f5
      Kan Liang 提交于
      The proc files which is sorted with alphabetical order are evenly
      assigned to several synthesize threads to be processed in parallel.
      
      For 'perf top', the threads number hard code to online CPU number. The
      following patch will introduce an option to set it.
      
      For other perf tools, the thread number is 1. Because the process
      function is not ready for multithreading, e.g.
      process_synthesized_event.
      
      This patch series only support event synthesize multithreading for 'perf
      top'. For other tools, it can be done separately later.
      
      With multithread applied, the total processing time can get up to 1.56x
      speedup on Knights Mill for 'perf top'.
      
      For specific single event processing, the processing time could increase
      because of the lock contention. So proc_map_timeout may need to be
      increased. Otherwise some proc maps will be truncated.
      
      Based on my test, increasing the proc_map_timeout has small impact
      on the total processing time. The total processing time still get 1.49x
      speedup on Knights Mill after increasing the proc_map_timeout.
      The patch itself doesn't increase the proc_map_timeout.
      
      Doesn't need to implement multithreading for per task monitoring,
      perf_event__synthesize_thread_map. It doesn't have performance issue.
      
      Committer testing:
      
        # getconf _NPROCESSORS_ONLN
        4
        # perf trace --no-inherit -e clone -o /tmp/output perf top
        # tail -4 /tmp/bla
           0.124 ( 0.041 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7fc3eb3a8f30, parent_tidptr: 0x7fc3eb3a99d0, child_tidptr: 0x7fc3eb3a99d0, tls: 0x7fc3eb3a9700) = 9548 (perf)
           0.246 ( 0.023 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7fc3eaba7f30, parent_tidptr: 0x7fc3eaba89d0, child_tidptr: 0x7fc3eaba89d0, tls: 0x7fc3eaba8700) = 9549 (perf)
           0.286 ( 0.019 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7fc3ea3a6f30, parent_tidptr: 0x7fc3ea3a79d0, child_tidptr: 0x7fc3ea3a79d0, tls: 0x7fc3ea3a7700) = 9550 (perf)
         246.540 ( 0.047 ms): clone(flags: VM|FS|FILES|SIGHAND|THREAD|SYSVSEM|SETTLS|PARENT_SETTID|CHILD_CLEARTID, child_stack: 0x7fc3ea3a6f30, parent_tidptr: 0x7fc3ea3a79d0, child_tidptr: 0x7fc3ea3a79d0, tls: 0x7fc3ea3a7700) = 9551 (perf)
        #
      Signed-off-by: NKan Liang <kan.liang@intel.com>
      Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Acked-by: NJiri Olsa <jolsa@kernel.org>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Alexei Starovoitov <ast@kernel.org>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: He Kuang <hekuang@huawei.com>
      Cc: Lukasz Odzioba <lukasz.odzioba@intel.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Wang Nan <wangnan0@huawei.com>
      Link: http://lkml.kernel.org/r/1506696477-146932-4-git-send-email-kan.liang@intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      340b47f5
  17. 22 9月, 2017 1 次提交
    • A
      perf tools: Provide mutex wrappers for pthreads rwlocks · 0a7c74ea
      Arnaldo Carvalho de Melo 提交于
      Andi reported a performance drop in single threaded perf tools such as
      'perf script' due to the growing number of locks being put in place to
      allow for multithreaded tools, so wrap the POSIX threads rwlock routines
      with the names used for such kinds of locks in the Linux kernel and then
      allow for tools to ask for those locks to be used or not.
      
      I.e. a tool may have a multithreaded phase and then switch to single
      threaded, like the upcoming patches for the synthesizing of
      PERF_RECORD_{FORK,MMAP,etc} for pre-existing processes to then switch to
      single threaded mode in 'perf top'.
      
      The init routines will not be conditional, this way starting as single
      threaded to then move to multi threaded mode should be possible.
      Reported-by: NAndi Kleen <ak@linux.intel.com>
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Kan Liang <kan.liang@intel.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Wang Nan <wangnan0@huawei.com>
      Link: http://lkml.kernel.org/r/20170404161739.GH12903@kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      0a7c74ea
  18. 18 9月, 2017 2 次提交
  19. 02 9月, 2017 1 次提交
  20. 30 8月, 2017 1 次提交
    • J
      perf report: Calculate the average cycles of iterations · c4ee0625
      Jin Yao 提交于
      The branch history code has a loop detection function. With this, we can
      get the number of iterations by calculating the removed loops.
      
      While it would be nice for knowing the average cycles of iterations.
      This patch adds up the cycles in branch entries of removed loops and
      save the result to the next branch entry (e.g. branch entry A).
      
      Finally it will display the iteration number and average cycles at the
      "from" of branch entry A.
      
      For example:
      perf record -g -j any,save_type ./div
      perf report --branch-history --no-children --stdio
      
      --22.63%--main div.c:42 (RET CROSS_2M)
                compute_flag div.c:28 (cycles:2 iter:173115 avg_cycles:2)
                |
                 --10.73%--compute_flag div.c:27 (RET CROSS_2M)
                           rand rand.c:28 (cycles:1)
                           rand rand.c:28 (RET CROSS_2M)
                           __random random.c:298 (cycles:1)
                           __random random.c:297 (COND_BWD CROSS_2M)
                           __random random.c:295 (cycles:1)
                           __random random.c:295 (COND_BWD CROSS_2M)
                           __random random.c:295 (cycles:1)
                           __random random.c:295 (RET CROSS_2M)
      Signed-off-by: NYao Jin <yao.jin@linux.intel.com>
      Reviewed-by: NAndi Kleen <ak@linux.intel.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Kan Liang <kan.liang@intel.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1502111115-18305-1-git-send-email-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      c4ee0625
  21. 12 8月, 2017 1 次提交
    • T
      perf record: Fix wrong size in perf_record_mmap for last kernel module · 9ad4652b
      Thomas Richter 提交于
      During work on perf report for s390 I ran into the following issue:
      
      0 0x318 [0x78]: PERF_RECORD_MMAP -1/0:
              [0x3ff804d6990(0xfffffc007fb2966f) @ 0]:
              x /lib/modules/4.12.0perf1+/kernel/drivers/s390/net/qeth_l2.ko
      
      This is a PERF_RECORD_MMAP entry of the perf.data file with an invalid
      module size for qeth_l2.ko (the s390 ethernet device driver).
      
      Even a mainframe does not have 0xfffffc007fb2966f bytes of main memory.
      
      It turned out that this wrong size is created by the perf record
      command.  What happens is this function call sequence from
      __cmd_record():
      
        perf_session__new():
          perf_session__create_kernel_maps():
            machine__create_kernel_maps():
              machine__create_modules():   Creates map for all loaded kernel modules.
                modules__parse():   Reads /proc/modules and extracts module name and
                                    load address (1st and last column)
                  machine__create_module():   Called for every module found in /proc/modules.
                                    Creates a new map for every module found and enters
                                    module name and start address into the map. Since the
                                    module end address is unknown it is set to zero.
      
      This ends up with a kernel module map list sorted by module start
      addresses.  All module end addresses are zero.
      
      Last machine__create_kernel_maps() calls function map_groups__fixup_end().
      This function iterates through the maps and assigns each map entry's
      end address the successor map entry start address. The last entry of the
      map group has no successor, so ~0 is used as end to consume the remaining
      memory.
      
      Later __cmd_record calls function record__synthesize() which in turn calls
      perf_event__synthesize_kernel_mmap() and perf_event__synthesize_modules()
      to create PERF_REPORT_MMAP entries into the perf.data file.
      
      On s390 this results in the last module qeth_l2.ko
      (which has highest start address, see module table:
              [root@s8360047 perf]# cat /proc/modules
              qeth_l2 86016 1 - Live 0x000003ff804d6000
              qeth 266240 1 qeth_l2, Live 0x000003ff80296000
              ccwgroup 24576 1 qeth, Live 0x000003ff80218000
              vmur 36864 0 - Live 0x000003ff80182000
              qdio 143360 2 qeth_l2,qeth, Live 0x000003ff80002000
              [root@s8360047 perf]# )
      to be the last entry and its map has an end address of ~0.
      
      When the PERF_RECORD_MMAP entry is created for kernel module qeth_l2.ko
      its start address and length is written. The length is calculated in line:
          event->mmap.len   = pos->end - pos->start;
      and results in 0xffffffffffffffff - 0x3ff804d6990(*) = 0xfffffc007fb2966f
      
      (*) On s390 the module start address is actually determined by a __weak function
      named arch__fix_module_text_start() in machine__create_module().
      
      I think this improvable. We can use the module size (2nd column of /proc/modules)
      to get each loaded kernel module size and calculate its end address.
      Only for map entries which do not have a valid end address (end is still zero)
      we can use the heuristic we have now, that is use successor start address or ~0.
      Signed-off-by: NThomas-Mich Richter <tmricht@linux.vnet.ibm.com>
      Reviewed-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
      Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
      Cc: Zvonko Kosic <zvonko.kosic@de.ibm.com>
      LPU-Reference: 20170803134902.47207-2-tmricht@linux.vnet.ibm.com
      Link: http://lkml.kernel.org/n/tip-nmoqij5b5vxx7rq2ckwu8iaj@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      9ad4652b
  22. 26 7月, 2017 1 次提交
    • J
      perf report: Make --branch-history work without callgraphs(-g) option in perf record · b49a821e
      Jin Yao 提交于
        perf record -b -g <command>
        perf report --branch-history
      
      This merges the LBRs with the callgraphs.
      
      However it would be nice if it also works without callgraphs (-g) set in
      perf record, so that only the LBRs are displayed.  But currently perf
      report errors in this case. For example,
      
        perf record -b <command>
        perf report --branch-history
      
        Error:
        Selected -g or --branch-history but no callchain data. Did
        you call 'perf record' without -g?
      
      This patch displays the LBRs only even if callgraphs(-g) is not enabled
      in perf record.
      
      Change log:
      
      v2: According to Milian Wolff's comment, change the obsolete error
      message. Now the error message is:
      
                       ┌─Error:─────────────────────────────────────┐
                       │Selected -g or --branch-history.            │
                       │But no callchain or branch data.            │
                       │Did you call 'perf record' without -g or -b?│
                       │                                            │
                       │                                            │
                       │Press any key...                            │
                       └────────────────────────────────────────────┘
      
      When passing the last parameter to hists__fprintf,
      changes "|" to "||".
      
        hists__fprintf(hists, !quiet, 0, 0, rep->min_percent, stdout,
                       symbol_conf.use_callchain || symbol_conf.show_branchflag_count);
      Signed-off-by: NYao Jin <yao.jin@linux.intel.com>
      Reviewed-by: NAndi Kleen <ak@linux.intel.com>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Jiri Olsa <jolsa@kernel.org>
      Cc: Kan Liang <kan.liang@intel.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1494240182-28899-1-git-send-email-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      b49a821e
  23. 19 7月, 2017 1 次提交
    • J
      perf report: Show branch type in callchain entry · b851dd49
      Jin Yao 提交于
      Show branch type in callchain entry. The branch type is printed
      with other LBR information (such as cycles/abort/...).
      
      For example:
      
        perf record -g -j any,save_type
        perf report --branch-history --stdio --no-children
      
        38.50%  div.c:45                [.] main                    div
                |
                ---main div.c:42 (RET CROSS_2M cycles:2)
                   compute_flag div.c:28 (cycles:2)
                   compute_flag div.c:27 (RET CROSS_2M cycles:1)
                   rand rand.c:28 (cycles:1)
                   rand rand.c:28 (RET CROSS_2M cycles:1)
                   __random random.c:298 (cycles:1)
                   __random random.c:297 (COND_BWD CROSS_2M cycles:1)
                   __random random.c:295 (cycles:1)
                   __random random.c:295 (COND_BWD CROSS_2M cycles:1)
                   __random random.c:295 (cycles:1)
                   __random random.c:295 (RET CROSS_2M cycles:9)
      
      Change log
      
      v6: Remove the branch_type_str() since it's moved to branch.c.
      
      v5: Rewrite the branch info print code in util/callchain.c.
      
      v4: Comparing to previous version, the major changes are:
      Signed-off-by: NYao Jin <yao.jin@linux.intel.com>
      Acked-by: NJiri Olsa <jolsa@kernel.org>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Kan Liang <kan.liang@intel.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/1500379995-6449-8-git-send-email-yao.jin@linux.intel.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
      b851dd49