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| author |   NeilBrown <neilb@suse.de> | 2012-09-19 12:48:30 +1000 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2012-09-19 12:48:30 +1000 |
| commit | a852d7b8a0cf29499905c9243fa6d3fb93898b82 (patch) | |
| tree | 006200722d6313f3ed8680c2fee6bd8d66a9de91 | |
| parent | Linux 3.6-rc5 (diff) | |
| download | linux-dev-a852d7b8a0cf29499905c9243fa6d3fb93898b82.tar.xz linux-dev-a852d7b8a0cf29499905c9243fa6d3fb93898b82.zip | |
Revert "md/raid5: For odirect-write performance, do not set STRIPE_PREREAD_ACTIVE."
This reverts commit 895e3c5c58a80bb9e4e05d9ac38b4f30e0f97d80.
While this patch seemed like a good idea and did help some workloads,
it hurts other workloads.
Large sequential O_DIRECT writes were faster,
Small random O_DIRECT writes were slower.
Other changes (batching RAID5 writes) have improved the sequential
writes using a different mechanism, so the net result of this patch
is definitely negative. So revert it.
Reported-by: Shaohua Li <shli@kernel.org>
Tested-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
| -rw-r--r-- | drivers/md/raid5.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index adda94df5eb2..380cb68856b1 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -4192,7 +4192,7 @@ static void make_request(struct mddev *mddev, struct bio * bi) finish_wait(&conf->wait_for_overlap, &w); set_bit(STRIPE_HANDLE, &sh->state); clear_bit(STRIPE_DELAYED, &sh->state); - if ((bi->bi_rw & REQ_NOIDLE) && + if ((bi->bi_rw & REQ_SYNC) && !test_and_set_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) atomic_inc(&conf->preread_active_stripes); release_stripe_plug(mddev, sh); |