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  1. 23 Apr, 2020 2 commits
    • Tommi Rantala's avatar
      perf test session topology: Fix data path · dbd660e6
      Tommi Rantala authored 
      Commit 2d4f2799 ("perf data: Add global path holder") missed path
conversion in tests/topology.c, causing the "Session topology" testcase
to "hang" (waits forever for input from stdin) when doing "ssh $VM perf
test".

Can be reproduced by running "cat | perf test topo", and crashed by
replacing cat with true:

  $ true | perf test -v topo
  40: Session topology                                      :
  --- start ---
  test child forked, pid 3638
  templ file: /tmp/perf-test-QPvAch
  incompatible file format
  incompatible file format (rerun with -v to learn more)
  free(): invalid pointer
  test child interrupted
  ---- end ----
  Session topology: FAILED!

Committer testing:

Reproduced the above result before the patch and after it is back
working:

  # true | perf test -v topo
  41: Session topology                                      :
  --- start ---
  test child forked, pid 19374
  templ file: /tmp/perf-test-YOTEQg
  CPU 0, core 0, socket 0
  CPU 1, core 1, socket 0
  CPU 2, core 2, socket 0
  CPU 3, core 3, socket 0
  CPU 4, core 0, socket 0
  CPU 5, core 1, socket 0
  CPU 6, core 2, socket 0
  CPU 7, core 3, socket 0
  test child finished with 0
  ---- end ----
  Session topology: Ok
  #

Fixes: 2d4f2799 ("perf data: Add global path holder")
Signed-off-by: default avatarTommi Rantala <tommi.t.rantala@nokia.com>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: default avatarJiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mamatha Inamdar <mamatha4@linux.vnet.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20200423115341.562782-1-tommi.t.rantala@nokia.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      dbd660e6
    • Jin Yao's avatar
      perf stat: Improve runtime stat for interval mode · 197ba86f
      Jin Yao authored 
      For interval mode, the metric is printed after the '#' character if it
exists. But it's not calculated by the counts generated in this
interval.

See the following examples:

  root@kbl-ppc:~# perf stat -M CPI -I1000 --interval-count 2
  #           time             counts unit events
       1.000422803            764,809      inst_retired.any          #      2.9 CPI
       1.000422803          2,234,932      cycles
       2.001464585          1,960,061      inst_retired.any          #      1.6 CPI
       2.001464585          4,022,591      cycles

The second CPI should not be 1.6 (4,022,591/1,960,061 is 2.1)

  root@kbl-ppc:~# perf stat -e cycles,instructions -I1000 --interval-count 2
  #           time             counts unit events
       1.000429493          2,869,311      cycles
       1.000429493            816,875      instructions              #    0.28  insn per cycle
       2.001516426          9,260,973      cycles
       2.001516426          5,250,634      instructions              #    0.87  insn per cycle

The second 'insn per cycle' should not be 0.87 (5,250,634/9,260,973 is
0.57).

The current code uses a global variable 'rt_stat' for tracking and
updating the std dev of runtime stat. Unlike the counts, 'rt_stat' is not
reset for interval. While the counts are reset for interval.

  perf_stat_process_counter()
  {
          if (config->interval)
                  init_stats(ps->res_stats);
  }

So for interval mode, the 'rt_stat' variable should be reset too.

This patch resets 'rt_stat' before read_counters(), so the runtime stat
is only calculated by the counts generated in this interval.

With this patch:

  root@kbl-ppc:~# perf stat -M CPI -I1000 --interval-count 2
  #           time             counts unit events
       1.000420924          2,408,818      inst_retired.any          #      2.1 CPI
       1.000420924          5,010,111      cycles
       2.001448579          2,798,407      inst_retired.any          #      1.6 CPI
       2.001448579          4,599,861      cycles

  root@kbl-ppc:~# perf stat -e cycles,instructions -I1000 --interval-count 2
  #           time             counts unit events
       1.000428555          2,769,714      cycles
       1.000428555            774,462      instructions              #    0.28  insn per cycle
       2.001471562          3,595,904      cycles
       2.001471562          1,243,703      instructions              #    0.35  insn per cycle

Now the second 'insn per cycle' and CPI are calculated by the counts
generated in this interval.
Signed-off-by: default avatarJin Yao <yao.jin@linux.intel.com>
Acked-by: default avatarJiri Olsa <jolsa@redhat.com>
Tested-By: default avatarKajol Jain <kjain@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20200420145417.6864-1-yao.jin@linux.intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      197ba86f
  3. 22 Apr, 2020 6 commits
  5. 21 Apr, 2020 22 commits
  7. 20 Apr, 2020 9 commits
  9. 19 Apr, 2020 1 commit
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