Ignore events that are in off/error state or belong to a different PMU.
This patch originates from the following commit for ARM by Will Deacon:
- 65b4711ff513767341aa1915c822de6ec0de65cb
ARM: 6352/1: perf: fix event validation
The validate_event function in the ARM perf events backend has the
following problems:
1.) Events that are disabled count towards the cost.
2.) Events associated with other PMUs [for example, software events or
breakpoints] do not count towards the cost, but do fail validation,
causing the group to fail.
This patch changes validate_event so that it ignores events in the
PERF_EVENT_STATE_OFF state or that are scheduled for other PMUs.
Changes:
v4 - v3:
o None
v3 - v2:
o Keep all mentioned commits in the form of number + title + original
summary + (MIPS specific info when needed).
v2 - v1:
o Corrected the return value of the event check in validate_event().
Acked-by: Will Deacon <will.deacon@xxxxxxx>
Acked-by: David Daney <ddaney@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@xxxxxxxxx>
---
arch/mips/kernel/perf_event.c | 5 +++--
1 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/mips/kernel/perf_event.c b/arch/mips/kernel/perf_event.c
index 1ee44a3..3d55761 100644
--- a/arch/mips/kernel/perf_event.c
+++ b/arch/mips/kernel/perf_event.c
@@ -486,8 +486,9 @@ static int validate_event(struct cpu_hw_events *cpuc,
{
struct hw_perf_event fake_hwc = event->hw;
- if (event->pmu && event->pmu != &pmu)
- return 0;
+ /* Allow mixed event group. So return 1 to pass validation. */
+ if (event->pmu != &pmu || event->state <= PERF_EVENT_STATE_OFF)
+ return 1;
return mipspmu->alloc_counter(cpuc, &fake_hwc) >= 0;
}
--
1.7.1
