linux-kernel - [PATCH 05/32] perf/core: remove unused pmu->count

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Date:	Thu, 28 Apr 2016 21:43:11 -0700
From:	David Carrillo-Cisneros <davidcc@...gle.com>
To:	Peter Zijlstra <peterz@...radead.org>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Ingo Molnar <mingo@...hat.com>
Cc:	Vikas Shivappa <vikas.shivappa@...ux.intel.com>,
	Matt Fleming <matt.fleming@...el.com>,
	Tony Luck <tony.luck@...el.com>,
	Stephane Eranian <eranian@...gle.com>,
	Paul Turner <pjt@...gle.com>,
	David Carrillo-Cisneros <davidcc@...gle.com>, x86@...nel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 05/32] perf/core: remove unused pmu->count

CQM was the only user of pmu->count, no need to have it anymore.

Reviewed-by: Stephane Eranian <eranian@...gle.com>
Signed-off-by: David Carrillo-Cisneros <davidcc@...gle.com>
---
 include/linux/perf_event.h |  6 ------
 kernel/events/core.c       | 10 ----------
 kernel/trace/bpf_trace.c   |  5 ++---
 3 files changed, 2 insertions(+), 19 deletions(-)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 00bb6b5..8bb1532 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -373,12 +373,6 @@ struct pmu {
 	 */
 	size_t				task_ctx_size;
 
-
-	/*
-	 * Return the count value for a counter.
-	 */
-	u64 (*count)			(struct perf_event *event); /*optional*/
-
 	/*
 	 * Set up pmu-private data structures for an AUX area
 	 */
diff --git a/kernel/events/core.c b/kernel/events/core.c
index aae72d3..4aaec01 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3313,9 +3313,6 @@ unlock:
 
 static inline u64 perf_event_count(struct perf_event *event)
 {
-	if (event->pmu->count)
-		return event->pmu->count(event);
-
 	return __perf_event_count(event);
 }
 
@@ -3325,7 +3322,6 @@ static inline u64 perf_event_count(struct perf_event *event)
  *   - either for the current task, or for this CPU
  *   - does not have inherit set, for inherited task events
  *     will not be local and we cannot read them atomically
- *   - must not have a pmu::count method
  */
 u64 perf_event_read_local(struct perf_event *event)
 {
@@ -3353,12 +3349,6 @@ u64 perf_event_read_local(struct perf_event *event)
 	WARN_ON_ONCE(event->attr.inherit);
 
 	/*
-	 * It must not have a pmu::count method, those are not
-	 * NMI safe.
-	 */
-	WARN_ON_ONCE(event->pmu->count);
-
-	/*
 	 * If the event is currently on this CPU, its either a per-task event,
 	 * or local to this CPU. Furthermore it means its ACTIVE (otherwise
 	 * oncpu == -1).
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 3e4ffb3..7ef81b3 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -200,9 +200,8 @@ static u64 bpf_perf_event_read(u64 r1, u64 index, u64 r3, u64 r4, u64 r5)
 
 	event = file->private_data;
 
-	/* make sure event is local and doesn't have pmu::count */
-	if (event->oncpu != smp_processor_id() ||
-	    event->pmu->count)
+	/* make sure event is local */
+	if (event->oncpu != smp_processor_id())
 		return -EINVAL;
 
 	/*
-- 
2.8.0.rc3.226.g39d4020