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| author | Jens Axboe <axboe@fb.com> | 2016-09-16 13:59:14 -0600 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2016-09-16 14:03:04 -0600 |
| commit | 703fd1c0f177219e3a84e6c095c31dc566514d81 (patch) | |
| tree | 468875ddeecad8922369359e863e100d061995ef /block/blk-mq.c | |
| parent | 2849450ad39d2e699fda2d5c6f41e05d87fd7004 (diff) | |
| download | lwn-703fd1c0f177219e3a84e6c095c31dc566514d81.tar.gz lwn-703fd1c0f177219e3a84e6c095c31dc566514d81.zip | |
blk-mq: account higher order dispatch
We currently account a '0' dispatch, and anything above that still falls
below the range set by BLK_MQ_MAX_DISPATCH_ORDER. If we dispatch more,
we don't account it.
Change the last bucket to be inclusive of anything above the range we
track, and have the sysfs file reflect that by including a '+' in the
output:
$ cat /sys/block/nvme0n1/mq/0/dispatched
0 1006
1 20229
2 1
4 0
8 0
16 0
32+ 0
Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Diffstat (limited to 'block/blk-mq.c')
| -rw-r--r-- | block/blk-mq.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 7ddc7969fba4..0cb93625d812 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -789,6 +789,14 @@ static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list) } } +static inline unsigned int queued_to_index(unsigned int queued) +{ + if (!queued) + return 0; + + return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1); +} + /* * Run this hardware queue, pulling any software queues mapped to it in. * Note that this function currently has various problems around ordering @@ -877,10 +885,7 @@ static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx) dptr = &driver_list; } - if (!queued) - hctx->dispatched[0]++; - else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1))) - hctx->dispatched[ilog2(queued) + 1]++; + hctx->dispatched[queued_to_index(queued)]++; /* * Any items that need requeuing? Stuff them into hctx->dispatch, |