[tip:perf/urgent] perf, x86: Fixup the precise_ip computation

[tip-bot for Peter Zijlstra <a.p.zijlstra@chello.nl>]

Commit-ID:  5553be2620ac901c21a25657bd5b59f73254e6d5
Gitweb:     http://git.kernel.org/tip/5553be2620ac901c21a25657bd5b59f73254e6d5
Author:     Peter Zijlstra <a.p.zijlstra@chello.nl>
AuthorDate: Tue, 19 Oct 2010 14:38:11 +0200
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Fri, 22 Oct 2010 14:18:25 +0200

perf, x86: Fixup the precise_ip computation

In case we don't have PEBS, the LBR fixup doesn't make sense.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Stephane Eranian <eranian@google.com>
LKML-Reference: <20101019134808.354429461@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
 arch/x86/kernel/cpu/perf_event.c |    9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index fe73c18..f369c53 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -497,12 +497,13 @@ static int x86_pmu_hw_config(struct perf_event *event)
 		int precise = 0;
 
 		/* Support for constant skid */
-		if (x86_pmu.pebs)
+		if (x86_pmu.pebs) {
 			precise++;
 
-		/* Support for IP fixup */
-		if (x86_pmu.lbr_nr)
-			precise++;
+			/* Support for IP fixup */
+			if (x86_pmu.lbr_nr)
+				precise++;
+		}
 
 		if (event->attr.precise_ip > precise)
 			return -EOPNOTSUPP;