2019-05-14 00:38:04

by Stephane Eranian

Subject: [PATCH] perf/x86/intel: allow PEBS multi-entry in watermark mode

This patch fixes an issue introduced with:

583feb08e7f7 ("perf/x86/intel: Fix handling of wakeup_events for multi-entry PEBS")

The original patch prevented using multi-entry PEBS when wakeup_events != 0.
However given that wakeup_events is part of a union with wakeup_watermark, it
means that in watermark mode, PEBS multi-entry is also disabled which is not the
intent. This patch fixes this by checking is watermark mode is enabled.

Signed-off-by: Stephane Eranian <[email protected]>
Change-Id: I8362bbcf9035c860b64b4c2e8faf310ebd74c234
---
arch/x86/events/intel/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 416233f92b3c..613fabba2c99 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3280,7 +3280,7 @@ static int intel_pmu_hw_config(struct perf_event *event)
return ret;

if (event->attr.precise_ip) {
- if (!(event->attr.freq || event->attr.wakeup_events)) {
+ if (!(event->attr.freq || (event->attr.wakeup_events && !event->attr.watermark))) {
event->hw.flags |= PERF_X86_EVENT_AUTO_RELOAD;
if (!(event->attr.sample_type &
~intel_pmu_large_pebs_flags(event)))

2019-05-14 07:14:27

by tip-bot for Vasyl Gomonovych

Subject: [tip:perf/urgent] perf/x86/intel: Allow PEBS multi-entry in watermark mode

Commit-ID: c7a286577d7592720c2f179aadfb325a1ff48c95
Gitweb: https://git.kernel.org/tip/c7a286577d7592720c2f179aadfb325a1ff48c95
Author: Stephane Eranian <[email protected]>
AuthorDate: Mon, 13 May 2019 17:34:00 -0700
Committer: Ingo Molnar <[email protected]>
CommitDate: Tue, 14 May 2019 09:07:58 +0200

perf/x86/intel: Allow PEBS multi-entry in watermark mode

This patch fixes a restriction/bug introduced by:

583feb08e7f7 ("perf/x86/intel: Fix handling of wakeup_events for multi-entry PEBS")

The original patch prevented using multi-entry PEBS when wakeup_events != 0.
However given that wakeup_events is part of a union with wakeup_watermark, it
means that in watermark mode, PEBS multi-entry is also disabled which is not the
intent. This patch fixes this by checking is watermark mode is enabled.

Signed-off-by: Stephane Eranian <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Fixes: 583feb08e7f7 ("perf/x86/intel: Fix handling of wakeup_events for multi-entry PEBS")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
---
arch/x86/events/intel/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index ef763f535e3a..12ec402f4114 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3265,7 +3265,7 @@ static int intel_pmu_hw_config(struct perf_event *event)
return ret;

if (event->attr.precise_ip) {
- if (!(event->attr.freq || event->attr.wakeup_events)) {
+ if (!(event->attr.freq || (event->attr.wakeup_events && !event->attr.watermark))) {
event->hw.flags |= PERF_X86_EVENT_AUTO_RELOAD;
if (!(event->attr.sample_type &
~intel_pmu_large_pebs_flags(event)))