[PATCH 4/7] perf, x86: Fixup the precise_ip computation

From: Peter Zijlstra
Date: Tue Oct 19 2010 - 09:55:24 EST


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

Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
LKML-Reference: <new-submission>
---
arch/x86/kernel/cpu/perf_event.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

Index: linux-2.6/arch/x86/kernel/cpu/perf_event.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/perf_event.c
+++ linux-2.6/arch/x86/kernel/cpu/perf_event.c
@@ -497,12 +497,13 @@ static int x86_pmu_hw_config(struct perf
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;


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/