linux-kernel - [tip:perf/pebs] perf, x86: Fix pebs drains

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Message-ID: <tip-8f4aebd2be9892bf8fb79a2d8576d3f3ee7f00f6@git.kernel.org>
Date:	Wed, 10 Mar 2010 13:22:18 GMT
From:	tip-bot for Peter Zijlstra <a.p.zijlstra@...llo.nl>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...hat.com,
	acme@...radead.org, a.p.zijlstra@...llo.nl, tglx@...utronix.de,
	mingo@...e.hu
Subject: [tip:perf/pebs] perf, x86: Fix pebs drains

Commit-ID:  8f4aebd2be9892bf8fb79a2d8576d3f3ee7f00f6
Gitweb:     http://git.kernel.org/tip/8f4aebd2be9892bf8fb79a2d8576d3f3ee7f00f6
Author:     Peter Zijlstra <a.p.zijlstra@...llo.nl>
AuthorDate: Sat, 6 Mar 2010 13:26:11 +0100
Committer:  Ingo Molnar <mingo@...e.hu>
CommitDate: Wed, 10 Mar 2010 13:23:36 +0100

perf, x86: Fix pebs drains

I overlooked the perf_disable()/perf_enable() calls in
intel_pmu_handle_irq(), (pointed out by Markus) so we should not
explicitly disable_all/enable_all pebs counters in the drain functions,
these are already disabled and enabling them early is confusing.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@...llo.nl>
Cc: Arnaldo Carvalho de Melo <acme@...radead.org>
Cc: paulus@...ba.org
Cc: eranian@...gle.com
Cc: robert.richter@....com
Cc: fweisbec@...il.com
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@...e.hu>
---
 arch/x86/kernel/cpu/perf_event_intel_ds.c |   15 +++------------
 1 files changed, 3 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index a7401e4..66c6962 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -476,18 +476,16 @@ static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
 	if (!event || !ds || !x86_pmu.pebs)
 		return;
 
-	intel_pmu_pebs_disable_all();
-
 	at  = (struct pebs_record_core *)(unsigned long)ds->pebs_buffer_base;
 	top = (struct pebs_record_core *)(unsigned long)ds->pebs_index;
 
 	if (top <= at)
-		goto out;
+		return;
 
 	ds->pebs_index = ds->pebs_buffer_base;
 
 	if (!intel_pmu_save_and_restart(event))
-		goto out;
+		return;
 
 	perf_sample_data_init(&data, 0);
 	data.period = event->hw.last_period;
@@ -528,9 +526,6 @@ static void intel_pmu_drain_pebs_core(struct pt_regs *iregs)
 
 	if (perf_event_overflow(event, 1, &data, &regs))
 		x86_pmu_stop(event);
-
-out:
-	intel_pmu_pebs_enable_all();
 }
 
 static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
@@ -547,13 +542,11 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
 	if (!ds || !x86_pmu.pebs)
 		return;
 
-	intel_pmu_pebs_disable_all();
-
 	at  = (struct pebs_record_nhm *)(unsigned long)ds->pebs_buffer_base;
 	top = (struct pebs_record_nhm *)(unsigned long)ds->pebs_index;
 
 	if (top <= at)
-		goto out;
+		return;
 
 	ds->pebs_index = ds->pebs_buffer_base;
 
@@ -604,8 +597,6 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
 		if (perf_event_overflow(event, 1, &data, &regs))
 			x86_pmu_stop(event);
 	}
-out:
-	intel_pmu_pebs_enable_all();
 }
 
 /*
--
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