[PATCH 4/5] perf/powerpc: Count dropped samples in core-book3s PMU
Namhyung Kim
namhyung at kernel.org
Thu Sep 5 13:10:26 AEST 2024
Due to the hardware limitation, sometimes it could sample kernel address
while attr.exclude_kernel is set. In that case it silently drops the
sample. Let's count that case in the new dropped_samples counter.
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Nicholas Piggin <npiggin at gmail.com>
Cc: Christophe Leroy <christophe.leroy at csgroup.eu>
Cc: Naveen N Rao <naveen at kernel.org>
Cc: Kajol Jain <kjain at linux.ibm.com>
Cc: Athira Rajeev <atrajeev at linux.vnet.ibm.com>
Cc: linuxppc-dev at lists.ozlabs.org
Signed-off-by: Namhyung Kim <namhyung at kernel.org>
---
arch/powerpc/perf/core-book3s.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 42867469752d73cf..553e288b9f113836 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -2287,8 +2287,10 @@ static void record_and_restart(struct perf_event *event, unsigned long val,
*/
if (event->attr.exclude_kernel &&
(event->attr.sample_type & PERF_SAMPLE_IP) &&
- is_kernel_addr(mfspr(SPRN_SIAR)))
+ is_kernel_addr(mfspr(SPRN_SIAR))) {
+ atomic64_inc(&event->dropped_samples);
record = 0;
+ }
/*
* Finally record data if requested.
--
2.46.0.469.g59c65b2a67-goog
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