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| author | Shaohua Li <shli@fb.com> | 2016-05-09 17:22:15 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2016-05-10 08:41:37 -0600 |
| commit | 59fa0224cfea31dde596e29555de94c961b139f9 (patch) | |
| tree | 4d0812a3b897bc9f1ad1ca45bd156141b5c8b946 | |
| parent | 8d1547e08dda8848f01185b3fd6bb946b68de99f (diff) | |
| download | linux-0-day-59fa0224cfea31dde596e29555de94c961b139f9.tar.gz linux-0-day-59fa0224cfea31dde596e29555de94c961b139f9.tar.xz | |
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 <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
| -rw-r--r-- | block/blk-throttle.c | 5 | ||||
| -rw-r--r-- | include/linux/blktrace_api.h | 9 |
2 files changed, 11 insertions, 3 deletions
diff --git a/block/blk-throttle.c b/block/blk-throttle.c index 2149a1ddbacf2..47a3e540631a3 100644 --- a/block/blk-throttle.c +++ b/block/blk-throttle.c @@ -211,15 +211,14 @@ static struct throtl_data *sq_to_td(struct throtl_service_queue *sq) * * The messages are prefixed with "throtl BLKG_NAME" if @sq belongs to a * throtl_grp; otherwise, just "throtl". - * - * TODO: this should be made a function and name formatting should happen - * after testing whether blktrace is enabled. */ #define throtl_log(sq, fmt, args...) do { \ struct throtl_grp *__tg = sq_to_tg((sq)); \ struct throtl_data *__td = sq_to_td((sq)); \ \ (void)__td; \ + if (likely(!blk_trace_note_message_enabled(__td->queue))) \ + break; \ if ((__tg)) { \ char __pbuf[128]; \ \ diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h index afc1343df3c7a..0f3172b8b2259 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; |