[PATCH AUTOSEL 4.14 20/99] perf/x86/intel: Allow PEBS multi-entry in watermark mode

From: Sasha Levin
Date: Sat Jun 01 2019 - 09:36:56 EST

From: Stephane Eranian <eranian@xxxxxxxxxx>

[ Upstream commit c7a286577d7592720c2f179aadfb325a1ff48c95 ]

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 <eranian@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: jolsa@xxxxxxxxxx
Cc: kan.liang@xxxxxxxxx
Cc: vincent.weaver@xxxxxxxxx
Fixes: 583feb08e7f7 ("perf/x86/intel: Fix handling of wakeup_events for multi-entry PEBS")
Link: http://lkml.kernel.org/r/20190514003400.224340-1-eranian@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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 0b93f5519ddab..d44bb077c6cfd 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3051,7 +3051,7 @@ 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 &