[tip: perf/core] perf: Use sample_flags for callchain

From: tip-bot2 for Namhyung Kim
Date: Thu Sep 15 2022 - 10:16:57 EST


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

Commit-ID: 3749d33e510c3dc695b3a5886b706310890d7ebd
Gitweb: https://git.kernel.org/tip/3749d33e510c3dc695b3a5886b706310890d7ebd
Author: Namhyung Kim <namhyung@xxxxxxxxxx>
AuthorDate: Thu, 08 Sep 2022 14:41:02 -07:00
Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
CommitterDate: Tue, 13 Sep 2022 15:03:22 +02:00

perf: Use sample_flags for callchain

So that it can call perf_callchain() only if needed. Historically it used
__PERF_SAMPLE_CALLCHAIN_EARLY but we can do that with sample_flags in the
struct perf_sample_data.

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220908214104.3851807-1-namhyung@xxxxxxxxxx
---
arch/x86/events/amd/ibs.c | 4 +++-
arch/x86/events/intel/ds.c | 8 ++++++--
kernel/events/core.c | 2 +-
3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/x86/events/amd/ibs.c b/arch/x86/events/amd/ibs.c
index c251bc4..dab0941 100644
--- a/arch/x86/events/amd/ibs.c
+++ b/arch/x86/events/amd/ibs.c
@@ -798,8 +798,10 @@ fail:
* recorded as part of interrupt regs. Thus we need to use rip from
* interrupt regs while unwinding call stack.
*/
- if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)
+ if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN) {
data.callchain = perf_callchain(event, iregs);
+ data.sample_flags |= PERF_SAMPLE_CALLCHAIN;
+ }

throttle = perf_event_overflow(event, &data, &regs);
out:
diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index a5275c2..4ba6ab6 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -1546,8 +1546,10 @@ static void setup_pebs_fixed_sample_data(struct perf_event *event,
* previous PMI context or an (I)RET happened between the record and
* PMI.
*/
- if (sample_type & PERF_SAMPLE_CALLCHAIN)
+ if (sample_type & PERF_SAMPLE_CALLCHAIN) {
data->callchain = perf_callchain(event, iregs);
+ data->sample_flags |= PERF_SAMPLE_CALLCHAIN;
+ }

/*
* We use the interrupt regs as a base because the PEBS record does not
@@ -1719,8 +1721,10 @@ static void setup_pebs_adaptive_sample_data(struct perf_event *event,
* previous PMI context or an (I)RET happened between the record and
* PMI.
*/
- if (sample_type & PERF_SAMPLE_CALLCHAIN)
+ if (sample_type & PERF_SAMPLE_CALLCHAIN) {
data->callchain = perf_callchain(event, iregs);
+ data->sample_flags |= PERF_SAMPLE_CALLCHAIN;
+ }

*regs = *iregs;
/* The ip in basic is EventingIP */
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 3e90e45..c98ecf3 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7320,7 +7320,7 @@ void perf_prepare_sample(struct perf_event_header *header,
if (sample_type & PERF_SAMPLE_CALLCHAIN) {
int size = 1;

- if (!(sample_type & __PERF_SAMPLE_CALLCHAIN_EARLY))
+ if (filtered_sample_type & PERF_SAMPLE_CALLCHAIN)
data->callchain = perf_callchain(event, regs);

size += data->callchain->nr;