[tip:perf/pebs] perf, x86: Avoid double disable on throttle vs ioctl(PERF_IOC_DISABLE)

[tip-bot for Peter Zijlstra]

Commit-ID:  cc7f00820b2f3be656569c41158d9323e425bcfe
Gitweb:     http://git.kernel.org/tip/cc7f00820b2f3be656569c41158d9323e425bcfe
Author:     Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
AuthorDate: Mon, 8 Mar 2010 17:51:33 +0100
Committer:  Ingo Molnar <mingo@xxxxxxx>
CommitDate: Wed, 10 Mar 2010 13:23:36 +0100

perf, x86: Avoid double disable on throttle vs ioctl(PERF_IOC_DISABLE)

Calling ioctl(PERF_EVENT_IOC_DISABLE) on a thottled counter would result
in a double disable, cure this by using x86_pmu_{start,stop} for
throttle/unthrottle and teach x86_pmu_stop() to check ->active_mask.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxxxxx>
Cc: paulus@xxxxxxxxx
Cc: eranian@xxxxxxxxxx
Cc: robert.richter@xxxxxxx
Cc: fweisbec@xxxxxxxxx
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
 arch/x86/kernel/cpu/perf_event_intel_ds.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index e7ac517..a7401e4 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -461,7 +461,6 @@ static int intel_pmu_pebs_fixup_ip(struct pt_regs *regs)
 }
 
 static int intel_pmu_save_and_restart(struct perf_event *event);
-static void intel_pmu_disable_event(struct perf_event *event);
 
 static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
 {
@@ -528,7 +527,7 @@ static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
 		regs.flags &= ~PERF_EFLAGS_EXACT;
 
 	if (perf_event_overflow(event, 1, &data, &regs))
-		intel_pmu_disable_event(event);
+		x86_pmu_stop(event);
 
 out:
 	intel_pmu_pebs_enable_all();
@@ -603,7 +602,7 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
 			regs.flags &= ~PERF_EFLAGS_EXACT;
 
 		if (perf_event_overflow(event, 1, &data, &regs))
-			intel_pmu_disable_event(event);
+			x86_pmu_stop(event);
 	}
 out:
 	intel_pmu_pebs_enable_all();
--
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