lkml.org 
[lkml]   [2010]   [Jan]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:perf/core] perf_events, x86: Remove spurious counter reset from x86_pmu_enable()
Commit-ID:  18c01f8abff51e4910cc5ffb4b710e8c6eea60c9
Gitweb: http://git.kernel.org/tip/18c01f8abff51e4910cc5ffb4b710e8c6eea60c9
Author: Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Wed, 27 Jan 2010 23:07:49 +0100
Committer: Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 29 Jan 2010 09:01:49 +0100

perf_events, x86: Remove spurious counter reset from x86_pmu_enable()

At enable time the counter might still have a ->idx pointing to
a previously occupied location that might now be taken by
another event. Resetting the counter at that location with data
from this event will destroy the other counter's count.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <20100127221122.261477183@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/kernel/cpu/perf_event.c | 3 ---
1 files changed, 0 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 3fac0bf..518eb3e 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1762,9 +1762,6 @@ static int x86_pmu_enable(struct perf_event *event)
cpuc->n_events = n;
cpuc->n_added = n - n0;

- if (hwc->idx != -1)
- x86_perf_event_set_period(event, hwc, hwc->idx);
-
return 0;
}


\
 
 \ /
  Last update: 2010-01-29 10:33    [W:0.069 / U:0.292 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site