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  1. 08 Jul, 2010 2 commits
    • Frederic Weisbecker's avatar
      perf: Sync callchains with period based hits · 108553e1
      Frederic Weisbecker authored 
      Hists have their hits increased by the event period. And this
period based counting is the foundation of all the stats in
perf report.

But callchains still use the raw number of hits, without taking
the period into account. So when we compute the percentage,
absolute based percentages are totally broken, and relative ones
too in the first parent level. Because we pass the number of events
muliplied by their period as the total number of hits to the
callchain filtering, while callchains expect this number to be
the number of raw hits.

perf report -g graph was simply not working, showing no graph unless
the min percent was zero. And even there the percentage of the
branches was always 0. And may be fractal filtering was broken on
the first branch level too.

flat also was broken, but it was hidden because of other breakages.

Anyway fix this by counting using periods on callchains.
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
      108553e1
    • Frederic Weisbecker's avatar
      perf: Resurrect flat callchains · 97aa1052
      Frederic Weisbecker authored 
      Initialize the callchain radix tree root correctly.

When we walk through the parents, we must stop after the root, but
since it wasn't well initialized, its parent pointer was random.

Also the number of hits was random because uninitialized, hence it
was part of the callchain while the root doesn't contain anything.

This fixes segfaults and percentages followed by empty callchains
while running:

	perf report -g flat
Reported-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: 2.6.31.x-2.6.34.x <stable@kernel.org>
      97aa1052
  3. 05 Jul, 2010 10 commits
  5. 04 Jul, 2010 1 commit
    • Will Deacon's avatar
      ARM: 6205/1: perf: ensure counter delta is treated as unsigned · 446a5a8b
      Will Deacon authored 
      Hardware performance counters on ARM are 32-bits wide but atomic64_t
variables are used to represent counter data in the hw_perf_event structure.

The armpmu_event_update function right-shifts a signed 64-bit delta variable
and adds the result to the event count. This can lead to shifting in sign-bits
if the MSB of the 32-bit counter value is set. This results in perf output
such as:

 Performance counter stats for 'sleep 20':

 18446744073460670464  cycles             <-- 0xFFFFFFFFF12A6000
        7783773  instructions             #      0.000 IPC
            465  context-switches
            161  page-faults
        1172393  branches

   20.154242147  seconds time elapsed

This patch ensures that the delta value is treated as unsigned so that the
right shift sets the upper bits to zero.

Cc: <stable@kernel.org>
Acked-by: default avatarJamie Iles <jamie.iles@picochip.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      446a5a8b
  7. 03 Jul, 2010 1 commit
  9. 02 Jul, 2010 15 commits
  11. 01 Jul, 2010 11 commits
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