[PATCH] powerpc, perf: Clear out branch entries to avoid any previous stale values
From: Anshuman Khandual <hidden>
Date: 2013-05-06 09:51:47
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
The 'to' field inside branch entries might contain stale values from previous PMU interrupt instances which had indirect branches. So clear all the values before reading a fresh set of BHRB entries after a PMU interrupt. Signed-off-by: Anshuman Khandual <redacted> --- arch/powerpc/perf/core-book3s.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index c627843..09db68d 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c@@ -1590,6 +1590,8 @@ static void record_and_restart(struct perf_event *event, unsigned long val, if (event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK) { struct cpu_hw_events *cpuhw; cpuhw = &__get_cpu_var(cpu_hw_events); + memset(cpuhw->bhrb_entries, 0, + sizeof(struct perf_branch_entry) * BHRB_MAX_ENTRIES); power_pmu_bhrb_read(cpuhw); data.br_stack = &cpuhw->bhrb_stack; }
--
1.7.11.7