Thread (16 messages) flat view 16 messages, 3 authors, 2018-06-11
STALE3027d

Revision v2 of 4 in this series.

Revisions (4)
  1. v2 current
  2. v3 [diff vs current]
  3. v4 [diff vs current]
  4. v5 [diff vs current]

[PATCH v2 4/5] arm_pmu: Tidy up clear_event_idx call backs

From: suzuki.poulose@arm.com (Suzuki K Poulose)
Date: 2018-05-29 10:56:24
Also in: lkml
Subsystem: arm pmu profiling and debugging, arm port, performance events subsystem, the rest · Maintainers: Will Deacon, Mark Rutland, Russell King, Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds

The armpmu uses get_event_idx callback to allocate an event
counter for a given event, which marks the selected counter
as "used". Now, when we delete the counter, the arm_pmu goes
ahead and clears the "used" bit and then invokes the "clear_event_idx"
call back, which kind of splits the job between the core code
and the backend. Tidy this up by relying on the clear_event_idx
to do the book keeping, if available. Otherwise, let the core
driver do the default "clear" bit operation. This will be useful
for adding the chained event support, where we leave the event
idx maintenance to the backend.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <redacted>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 arch/arm/kernel/perf_event_v7.c |  2 ++
 drivers/perf/arm_pmu.c          | 15 +++++++++++----
 2 files changed, 13 insertions(+), 4 deletions(-)
diff --git a/arch/arm/kernel/perf_event_v7.c b/arch/arm/kernel/perf_event_v7.c
index 5f342fc..5e78faa 100644
--- a/arch/arm/kernel/perf_event_v7.c
+++ b/arch/arm/kernel/perf_event_v7.c
@@ -1638,6 +1638,7 @@ static void krait_pmu_clear_event_idx(struct pmu_hw_events *cpuc,
 	bool venum_event = EVENT_VENUM(hwc->config_base);
 	bool krait_event = EVENT_CPU(hwc->config_base);
 
+	clear_bit(hwc->idx, cpuc->used_mask);
 	if (venum_event || krait_event) {
 		bit = krait_event_to_bit(event, region, group);
 		clear_bit(bit, cpuc->used_mask);
@@ -1967,6 +1968,7 @@ static void scorpion_pmu_clear_event_idx(struct pmu_hw_events *cpuc,
 	bool venum_event = EVENT_VENUM(hwc->config_base);
 	bool scorpion_event = EVENT_CPU(hwc->config_base);
 
+	clear_bit(hwc->idx, cpuc->used_mask);
 	if (venum_event || scorpion_event) {
 		bit = scorpion_event_to_bit(event, region, group);
 		clear_bit(bit, cpuc->used_mask);
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index ff858e6..9ae7e68 100644
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -226,6 +226,16 @@ static void armpmu_start(struct perf_event *event, int flags)
 	armpmu->enable(event);
 }
 
+static void armpmu_clear_event_idx(struct arm_pmu *armpmu,
+				   struct pmu_hw_events *hw_events,
+				   struct perf_event *event)
+{
+	if (armpmu->clear_event_idx)
+		armpmu->clear_event_idx(hw_events, event);
+	else
+		clear_bit(event->hw.idx, hw_events->used_mask);
+}
+
 static void
 armpmu_del(struct perf_event *event, int flags)
 {
@@ -236,10 +246,7 @@ armpmu_del(struct perf_event *event, int flags)
 
 	armpmu_stop(event, PERF_EF_UPDATE);
 	hw_events->events[idx] = NULL;
-	clear_bit(idx, hw_events->used_mask);
-	if (armpmu->clear_event_idx)
-		armpmu->clear_event_idx(hw_events, event);
-
+	armpmu_clear_event_idx(armpmu, hw_events, event);
 	perf_event_update_userpage(event);
 }
 
-- 
2.7.4
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help