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| author | Yu Kuai <yukuai3@huawei.com> | 2023-06-21 12:57:28 +0200 |
|---|---|---|
| committer | Song Liu <song@kernel.org> | 2023-06-23 18:41:50 +0200 |
| commit | a8d5fdd4d2702d0c7ec125bd3bbce3fc589afa67 (patch) | |
| tree | ba89c5dc6f8ca44798d01ef22d559304c8cc830d /drivers/md/raid10.c | |
| parent | md: fix 'delete_mutex' deadlock (diff) | |
| download | linux-a8d5fdd4d2702d0c7ec125bd3bbce3fc589afa67.tar.xz linux-a8d5fdd4d2702d0c7ec125bd3bbce3fc589afa67.zip | |
raid10: avoid spin_lock from fastpath from raid10_unplug()
Commit 0c0be98bbe67 ("md/raid10: prevent unnecessary calls to wake_up()
in fast path") missed one place, for example, with:
fio -direct=1 -rw=write/randwrite -iodepth=1 ...
Plug and unplug are called for each io, then wake_up() from raid10_unplug()
will cause lock contention as well.
Avoid this contention by using wake_up_barrier() instead of wake_up(),
where spin_lock is not held if waitqueue is empty.
Fio test script:
[global]
name=random reads and writes
ioengine=libaio
direct=1
readwrite=randrw
rwmixread=70
iodepth=64
buffered=0
filename=/dev/md0
size=1G
runtime=30
time_based
randrepeat=0
norandommap
refill_buffers
ramp_time=10
bs=4k
numjobs=400
group_reporting=1
[job1]
Test result with ramdisk raid10(By Ali):
Before this patch With this patch
READ IOPS=2033k IOPS=3642k
WRITE IOPS=871k IOPS=1561K
By the way, in this scenario, blk_plug_cb() will be allocated and freed
for each io, this seems need to be optimized as well.
Reported-and-tested-by: Ali Gholami Rudi <aligrudi@gmail.com>
Closes: https://lore.kernel.org/all/20231606122233@laper.mirepesht/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230621105728.1268542-1-yukuai1@huaweicloud.com
Diffstat (limited to '')
| -rw-r--r-- | drivers/md/raid10.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 79067769e44b..5051149e27bb 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1118,7 +1118,7 @@ static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule) spin_lock_irq(&conf->device_lock); bio_list_merge(&conf->pending_bio_list, &plug->pending); spin_unlock_irq(&conf->device_lock); - wake_up(&conf->wait_barrier); + wake_up_barrier(conf); md_wakeup_thread(mddev->thread); kfree(plug); return; @@ -1127,7 +1127,7 @@ static void raid10_unplug(struct blk_plug_cb *cb, bool from_schedule) /* we aren't scheduling, so we can do the write-out directly. */ bio = bio_list_get(&plug->pending); raid1_prepare_flush_writes(mddev->bitmap); - wake_up(&conf->wait_barrier); + wake_up_barrier(conf); while (bio) { /* submit pending writes */ struct bio *next = bio->bi_next; |