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| author | Jens Axboe <axboe@kernel.dk> | 2023-02-15 16:43:47 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-10 09:34:14 +0100 |
| commit | 95bb37e077db59998d04d633099c366df26d379f (patch) | |
| tree | 0694562c49d068f69b86ccd8cd1fdf60f0607b9d /drivers/block | |
| parent | 3adf063bac2f17e5216a0312165aeb0a91af4a94 (diff) | |
| download | linux-95bb37e077db59998d04d633099c366df26d379f.tar.gz | |
brd: mark as nowait compatible
commit 67205f80be9910207481406c47f7d85e703fb2e9 upstream. By default, non-mq drivers do not support nowait. This causes io_uring to use a slower path as the driver cannot be trust not to block. brd can safely set the nowait flag, as worst case all it does is a NOIO allocation. For io_uring, this makes a substantial difference. Before: submitter=0, tid=453, file=/dev/ram0, node=-1 polled=0, fixedbufs=1/0, register_files=1, buffered=0, QD=128 Engine=io_uring, sq_ring=128, cq_ring=128 IOPS=440.03K, BW=1718MiB/s, IOS/call=32/31 IOPS=428.96K, BW=1675MiB/s, IOS/call=32/32 IOPS=442.59K, BW=1728MiB/s, IOS/call=32/31 IOPS=419.65K, BW=1639MiB/s, IOS/call=32/32 IOPS=426.82K, BW=1667MiB/s, IOS/call=32/31 and after: submitter=0, tid=354, file=/dev/ram0, node=-1 polled=0, fixedbufs=1/0, register_files=1, buffered=0, QD=128 Engine=io_uring, sq_ring=128, cq_ring=128 IOPS=3.37M, BW=13.15GiB/s, IOS/call=32/31 IOPS=3.45M, BW=13.46GiB/s, IOS/call=32/31 IOPS=3.43M, BW=13.42GiB/s, IOS/call=32/32 IOPS=3.43M, BW=13.39GiB/s, IOS/call=32/31 IOPS=3.43M, BW=13.38GiB/s, IOS/call=32/31 or about an 8x in difference. Now that brd is prepared to deal with REQ_NOWAIT reads/writes, mark it as supporting that. Cc: stable@vger.kernel.org # 5.10+ Link: https://lore.kernel.org/linux-block/20230203103005.31290-1-p.raghav@samsung.com/ Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/brd.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/block/brd.c b/drivers/block/brd.c index 20acc4a1fd6d..82419e345777 100644 --- a/drivers/block/brd.c +++ b/drivers/block/brd.c @@ -412,6 +412,7 @@ static int brd_alloc(int i) /* Tell the block layer that this is not a rotational device */ blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue); blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, disk->queue); + blk_queue_flag_set(QUEUE_FLAG_NOWAIT, disk->queue); err = add_disk(disk); if (err) goto out_cleanup_disk; |