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| author | Jens Axboe <axboe@fb.com> | 2016-11-08 07:32:37 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2016-11-10 23:53:26 +0300 |
| commit | cf43e6be865a582ba66ee4747ae27a0513f6bba1 (patch) | |
| tree | 53b71dd2f456e4880428683631fd09c9dc0747a5 /include/linux/blkdev.h | |
| parent | ebc4ff661fbe76781c6b16dfb7b754a5d5073f8e (diff) | |
| download | linux-cf43e6be865a582ba66ee4747ae27a0513f6bba1.tar.xz | |
block: add scalable completion tracking of requests
For legacy block, we simply track them in the request queue. For
blk-mq, we track them on a per-sw queue basis, which we can then
sum up through the hardware queues and finally to a per device
state.
The stats are tracked in, roughly, 0.1s interval windows.
Add sysfs files to display the stats.
The feature is off by default, to avoid any extra overhead. In-kernel
users of it can turn it on by setting QUEUE_FLAG_STATS in the queue
flags. We currently don't turn it on if someone just reads any of
the stats files, that is something we could add as well.
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'include/linux/blkdev.h')
| -rw-r--r-- | include/linux/blkdev.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index d364be6e6959..303723a2e5b8 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -117,6 +117,8 @@ typedef __u32 __bitwise req_flags_t; #define RQF_PM ((__force req_flags_t)(1 << 15)) /* on IO scheduler merge hash */ #define RQF_HASHED ((__force req_flags_t)(1 << 16)) +/* IO stats tracking on */ +#define RQF_STATS ((__force req_flags_t)(1 << 17)) /* flags that prevent us from merging requests: */ #define RQF_NOMERGE_FLAGS \ @@ -197,6 +199,7 @@ struct request { struct gendisk *rq_disk; struct hd_struct *part; unsigned long start_time; + struct blk_issue_stat issue_stat; #ifdef CONFIG_BLK_CGROUP struct request_list *rl; /* rl this rq is alloced from */ unsigned long long start_time_ns; @@ -492,6 +495,9 @@ struct request_queue { unsigned int nr_sorted; unsigned int in_flight[2]; + + struct blk_rq_stat rq_stats[2]; + /* * Number of active block driver functions for which blk_drain_queue() * must wait. Must be incremented around functions that unlock the @@ -585,6 +591,7 @@ struct request_queue { #define QUEUE_FLAG_FUA 24 /* device supports FUA writes */ #define QUEUE_FLAG_FLUSH_NQ 25 /* flush not queueuable */ #define QUEUE_FLAG_DAX 26 /* device supports DAX */ +#define QUEUE_FLAG_STATS 27 /* track rq completion times */ #define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \ (1 << QUEUE_FLAG_STACKABLE) | \ |