From 59fa0224cfea31dde596e29555de94c961b139f9 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Mon, 9 May 2016 17:22:15 -0700 Subject: blk-throttle: don't parse cgroup path if trace isn't enabled if trace isn't enabled, parsing cgroup path just wastes cpu Signed-off-by: Shaohua Li Signed-off-by: Jens Axboe --- include/linux/blktrace_api.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'include/linux/blktrace_api.h') diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h index afc1343df3c7..0f3172b8b225 100644 --- a/include/linux/blktrace_api.h +++ b/include/linux/blktrace_api.h @@ -57,6 +57,14 @@ void __trace_note_message(struct blk_trace *, const char *fmt, ...); } while (0) #define BLK_TN_MAX_MSG 128 +static inline bool blk_trace_note_message_enabled(struct request_queue *q) +{ + struct blk_trace *bt = q->blk_trace; + if (likely(!bt)) + return false; + return bt->act_mask & BLK_TC_NOTIFY; +} + extern void blk_add_driver_data(struct request_queue *q, struct request *rq, void *data, size_t len); extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, @@ -79,6 +87,7 @@ extern struct attribute_group blk_trace_attr_group; # define blk_trace_remove(q) (-ENOTTY) # define blk_add_trace_msg(q, fmt, ...) do { } while (0) # define blk_trace_remove_sysfs(dev) do { } while (0) +# define blk_trace_note_message_enabled(q) (false) static inline int blk_trace_init_sysfs(struct device *dev) { return 0; -- cgit