2023-04-27 03:06:24

by Namhyung Kim

Subject: [PATCH] perf/x86: Fix missing sample size update on AMD BRS

It missed to convert a PERF_SAMPLE_BRANCH_STACK user to call the new
perf_sample_save_brstack() helper in order to update the dyn_size.
This affects AMD Zen3 machines with the branch-brs event.

Fixes: eb55b455ef9c ("perf/core: Add perf_sample_save_brstack() helper")
Cc: [email protected]
Signed-off-by: Namhyung Kim <[email protected]>
---
arch/x86/events/core.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index d096b04bf80e..9d248703cbdd 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -1703,10 +1703,8 @@ int x86_pmu_handle_irq(struct pt_regs *regs)

perf_sample_data_init(&data, 0, event->hw.last_period);

- if (has_branch_stack(event)) {
- data.br_stack = &cpuc->lbr_stack;
- data.sample_flags |= PERF_SAMPLE_BRANCH_STACK;
- }
+ if (has_branch_stack(event))
+ perf_sample_save_brstack(&data, event, &cpuc->lbr_stack);

if (perf_event_overflow(event, &data, regs))
x86_pmu_stop(event, 0);
--
2.40.1.495.gc816e09b53d-goog

2023-05-10 13:36:58

by tip-bot2 for Alexey Makhalov

Subject: [tip: perf/urgent] perf/x86: Fix missing sample size update on AMD BRS

The following commit has been merged into the perf/urgent branch of tip:

Commit-ID: 90befef5a9e820ccccc33181ec14c015980300cc
Gitweb: https://git.kernel.org/tip/90befef5a9e820ccccc33181ec14c015980300cc
Author: Namhyung Kim <[email protected]>
AuthorDate: Wed, 26 Apr 2023 20:05:27 -07:00
Committer: Peter Zijlstra <[email protected]>
CommitterDate: Mon, 08 May 2023 10:58:26 +02:00

perf/x86: Fix missing sample size update on AMD BRS

It missed to convert a PERF_SAMPLE_BRANCH_STACK user to call the new
perf_sample_save_brstack() helper in order to update the dyn_size.
This affects AMD Zen3 machines with the branch-brs event.

Fixes: eb55b455ef9c ("perf/core: Add perf_sample_save_brstack() helper")
Signed-off-by: Namhyung Kim <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
---
arch/x86/events/core.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c
index d096b04..9d24870 100644
--- a/arch/x86/events/core.c
+++ b/arch/x86/events/core.c
@@ -1703,10 +1703,8 @@ int x86_pmu_handle_irq(struct pt_regs *regs)

perf_sample_data_init(&data, 0, event->hw.last_period);

- if (has_branch_stack(event)) {
- data.br_stack = &cpuc->lbr_stack;
- data.sample_flags |= PERF_SAMPLE_BRANCH_STACK;
- }
+ if (has_branch_stack(event))
+ perf_sample_save_brstack(&data, event, &cpuc->lbr_stack);

if (perf_event_overflow(event, &data, regs))
x86_pmu_stop(event, 0);