From: Peter Zijlstra <a.p.zijlstra@chello.nl>
Date: Wed, 10 Feb 2010 15:10:48 +0000 (+0100)
Subject: perf_events, x86: Remove superflous MSR writes
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6667661df4bc76083edf1e08831c20f64429709d;p=linux-beck.git

perf_events, x86: Remove superflous MSR writes

We re-program the event control register every time we reset the count,
this appears to be superflous, hence remove it.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arjan van de Ven <arjan@linux.intel.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index ad096562d694..dd09ccc867d3 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -2009,9 +2009,6 @@ static int intel_pmu_save_and_restart(struct perf_event *event)
 	x86_perf_event_update(event, hwc, idx);
 	ret = x86_perf_event_set_period(event, hwc, idx);
 
-	if (event->state == PERF_EVENT_STATE_ACTIVE)
-		intel_pmu_enable_event(hwc, idx);
-
 	return ret;
 }