linux-kernel - [tip:perf/pebs] perf, x86: Deal with multiple state bits for pebs-fmt1

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Message-ID: <tip-12ab854d744f04bfc5c6c4db723b7e31fc03eb29@git.kernel.org>
Date:	Wed, 10 Mar 2010 13:23:25 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: Deal with multiple state bits for pebs-fmt1

Commit-ID:  12ab854d744f04bfc5c6c4db723b7e31fc03eb29
Gitweb:     http://git.kernel.org/tip/12ab854d744f04bfc5c6c4db723b7e31fc03eb29
Author:     Peter Zijlstra <a.p.zijlstra@...llo.nl>
AuthorDate: Sat, 6 Mar 2010 18:57:38 +0100
Committer:  Ingo Molnar <mingo@...e.hu>
CommitDate: Wed, 10 Mar 2010 13:23:38 +0100

perf, x86: Deal with multiple state bits for pebs-fmt1

Its unclear if the PEBS state record will have only a single bit set, in
case it does not and accumulates bits, deal with that by only processing
each event once.

Also, robustify some of the code.

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 |   16 +++++++++++++---
 1 files changed, 13 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 9ad0e67..b4680da 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -538,6 +538,7 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
 	struct perf_event *event = NULL;
 	struct perf_raw_record raw;
 	struct pt_regs regs;
+	u64 status = 0;
 	int bit, n;
 
 	if (!ds || !x86_pmu.pebs)
@@ -561,13 +562,22 @@ static void intel_pmu_drain_pebs_nhm(struct pt_regs *iregs)
 
 	for ( ; at < top; at++) {
 		for_each_bit(bit, (unsigned long *)&at->status, MAX_PEBS_EVENTS) {
-			if (!cpuc->events[bit]->attr.precise)
+			event = cpuc->events[bit];
+			if (!test_bit(bit, cpuc->active_mask))
 				continue;
 
-			event = cpuc->events[bit];
+			WARN_ON_ONCE(!event);
+
+			if (!event->attr.precise)
+				continue;
+
+			if (__test_and_set_bit(bit, (unsigned long *)&status))
+				continue;
+
+			break;
 		}
 
-		if (!event)
+		if (!event || bit >= MAX_PEBS_EVENTS)
 			continue;
 
 		if (!intel_pmu_save_and_restart(event))
--
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