[PATCH v1 0/2] perf: Minor typo and style changes to perf_event.h

[PATCH v1 0/2] perf: Minor typo and style changes to perf_event.h

[Andrew Murray]

This series makes minor changes to perf_event.h to fix an incorrect
comment and to improve the readability of the annotations for the
optional callbacks.


Andrew Murray (2):
  perf: Fix incorrect comment for event_idx callback
  perf: Use consistent style of comments for optional callbacks

 include/linux/perf_event.h | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

-- 
2.21.0

[PATCH v1 1/2] perf: Fix incorrect comment for event_idx callback

[Andrew Murray]

The default implementation of the event_idx callback
(perf_event_idx_default) returns 0. Let's update the comment for the
callback to reflect this, as it currently indicates an incorrect value.

Signed-off-by: Andrew Murray <andrew.murray@arm.com>
---
 include/linux/perf_event.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index e47ef764f613..27c1cb3cddf1 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -392,7 +392,7 @@ struct pmu {
 
 	/*
 	 * Will return the value for perf_event_mmap_page::index for this event,
-	 * if no implementation is provided it will default to: event->hw.idx + 1.
+	 * if no implementation is provided it will default to: 0.
 	 */
 	int (*event_idx)		(struct perf_event *event); /*optional */
 
-- 
2.21.0

[PATCH v1 2/2] perf: Use consistent style of comments for optional callbacks

[Andrew Murray]

To improve the readability of perf_event.h, let's be consistent in how we
annotate optional struct pmu callbacks. Where a multi-line comment block
is present before a single function prototype we add the annotation at the
end of the block. Otherwise we use a single line comment at the end of the
function prototype.

Signed-off-by: Andrew Murray <andrew.murray@arm.com>
---
 include/linux/perf_event.h | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 27c1cb3cddf1..f0479c99d2ec 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -393,8 +393,10 @@ struct pmu {
 	/*
 	 * Will return the value for perf_event_mmap_page::index for this event,
 	 * if no implementation is provided it will default to: 0.
+	 *
+	 * Optional.
 	 */
-	int (*event_idx)		(struct perf_event *event); /*optional */
+	int (*event_idx)		(struct perf_event *event);
 
 	/*
 	 * context-switches callback
@@ -409,15 +411,18 @@ struct pmu {
 
 	/*
 	 * Set up pmu-private data structures for an AUX area
+	 *
+	 * Optional.
 	 */
 	void *(*setup_aux)		(struct perf_event *event, void **pages,
 					 int nr_pages, bool overwrite);
-					/* optional */
 
 	/*
 	 * Free pmu-private AUX data structures
+	 *
+	 * Optional.
 	 */
-	void (*free_aux)		(void *aux); /* optional */
+	void (*free_aux)		(void *aux);
 
 	/*
 	 * Validate address range filters: make sure the HW supports the
@@ -426,9 +431,10 @@ struct pmu {
 	 *
 	 * Runs in the context of the ioctl()ing process and is not serialized
 	 * with the rest of the PMU callbacks.
+	 *
+	 * Optional.
 	 */
 	int (*addr_filters_validate)	(struct list_head *filters);
-					/* optional */
 
 	/*
 	 * Synchronize address range filter configuration:
@@ -440,19 +446,24 @@ struct pmu {
 	 *
 	 * May (and should) traverse event::addr_filters::list, for which its
 	 * caller provides necessary serialization.
+	 *
+	 * Optional.
 	 */
 	void (*addr_filters_sync)	(struct perf_event *event);
-					/* optional */
 
 	/*
 	 * Filter events for PMU-specific reasons.
+	 *
+	 * Optional.
 	 */
-	int (*filter_match)		(struct perf_event *event); /* optional */
+	int (*filter_match)		(struct perf_event *event);
 
 	/*
 	 * Check period value for PERF_EVENT_IOC_PERIOD ioctl.
+	 *
+	 * Optional.
 	 */
-	int (*check_period)		(struct perf_event *event, u64 value); /* optional */
+	int (*check_period)		(struct perf_event *event, u64 value);
 };
 
 enum perf_addr_filter_action_t {
-- 
2.21.0