block/bfq: update comments and default value in docs for fifo_expire

Correct the comments since bfq_fifo_expire[0] is for async request,
while bfq_fifo_expire[1] is for sync request.
Also update docs, according the source code, the default
fifo_expire_async is 250ms, and fifo_expire_sync is 125ms.

Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Joseph Qi 2021-02-23 09:55:28 +08:00 committed by Jens Axboe
parent e4ef09e512
commit 4168a8d27e
2 changed files with 3 additions and 3 deletions

View File

@ -430,13 +430,13 @@ fifo_expire_async
-----------------
This parameter is used to set the timeout of asynchronous requests. Default
value of this is 248ms.
value of this is 250ms.
fifo_expire_sync
----------------
This parameter is used to set the timeout of synchronous requests. Default
value of this is 124ms. In case to favor synchronous requests over asynchronous
value of this is 125ms. In case to favor synchronous requests over asynchronous
one, this value should be decreased relative to fifo_expire_async.
low_latency

View File

@ -162,7 +162,7 @@ BFQ_BFQQ_FNS(split_coop);
BFQ_BFQQ_FNS(softrt_update);
#undef BFQ_BFQQ_FNS \
/* Expiration time of sync (0) and async (1) requests, in ns. */
/* Expiration time of async (0) and sync (1) requests, in ns. */
static const u64 bfq_fifo_expire[2] = { NSEC_PER_SEC / 4, NSEC_PER_SEC / 8 };
/* Maximum backwards seek (magic number lifted from CFQ), in KiB. */