Messages in this thread Patch in this message | | | From | Namhyung Kim <> | Subject | [PATCH 2/5] perf: Annotate lock context on perf_output_begin/end() | Date | Mon, 27 Sep 2010 19:39:54 +0900 |
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perf_output_begin() conditionally grabs RCU read lock in case of returning 0. Rename and wrap it using __cond_lock() to annotate this. Although perf_output_begin() returns 0 or error code, IMHO converting it to boolean will not be a problem since there is no user takes account of the actual code. Annotate perf_output_end() also.
Signed-off-by: Namhyung Kim <namhyung@gmail.com> --- include/linux/perf_event.h | 6 +++++- kernel/perf_event.c | 3 ++- 2 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 716f99b..167dd3d 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -1009,9 +1009,13 @@ extern void perf_bp_event(struct perf_event *event, void *data); #define perf_instruction_pointer(regs) instruction_pointer(regs) #endif -extern int perf_output_begin(struct perf_output_handle *handle, +extern int __perf_output_begin(struct perf_output_handle *handle, struct perf_event *event, unsigned int size, int nmi, int sample); + +#define perf_output_begin(h, e, s, n, sp) \ + (!__cond_lock(RCU, !__perf_output_begin(h, e, s, n, sp))) + extern void perf_output_end(struct perf_output_handle *handle); extern void perf_output_copy(struct perf_output_handle *handle, const void *buf, unsigned int len); diff --git a/kernel/perf_event.c b/kernel/perf_event.c index c058a42..bd5d750 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -3106,7 +3106,7 @@ __always_inline void perf_output_copy(struct perf_output_handle *handle, } while (len); } -int perf_output_begin(struct perf_output_handle *handle, +int __perf_output_begin(struct perf_output_handle *handle, struct perf_event *event, unsigned int size, int nmi, int sample) { @@ -3190,6 +3190,7 @@ out: } void perf_output_end(struct perf_output_handle *handle) + __releases(RCU) { struct perf_event *event = handle->event; struct perf_buffer *buffer = handle->buffer; -- 1.7.2.2
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