From: Jens Axboe axboe@kernel.dk
stable inclusion from stable-5.10.71 commit 0306a2c7df7ebe7c740ecb6c845668401ed3cc8e bugzilla: 182981 https://gitee.com/openeuler/kernel/issues/I4I3KD
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ Upstream commit ebc69e897e17373fbe1daaff1debaa77583a5284 ]
This reverts commit 2d52c58b9c9bdae0ca3df6a1eab5745ab3f7d80b.
We have had several folks complain that this causes hangs for them, which is especially problematic as the commit has also hit stable already.
As no resolution seems to be forthcoming right now, revert the patch.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=214503 Fixes: 2d52c58b9c9b ("block, bfq: honor already-setup queue merges") Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Chen Jun chenjun102@huawei.com Acked-by: Weilong Chen chenweilong@huawei.com
Signed-off-by: Chen Jun chenjun102@huawei.com --- block/bfq-iosched.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-)
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c index 3f6f401cae7e..fd3c23d516b8 100644 --- a/block/bfq-iosched.c +++ b/block/bfq-iosched.c @@ -2526,15 +2526,6 @@ bfq_setup_merge(struct bfq_queue *bfqq, struct bfq_queue *new_bfqq) * are likely to increase the throughput. */ bfqq->new_bfqq = new_bfqq; - /* - * The above assignment schedules the following redirections: - * each time some I/O for bfqq arrives, the process that - * generated that I/O is disassociated from bfqq and - * associated with new_bfqq. Here we increases new_bfqq->ref - * in advance, adding the number of processes that are - * expected to be associated with new_bfqq as they happen to - * issue I/O. - */ new_bfqq->ref += process_refs; return new_bfqq; } @@ -2594,10 +2585,6 @@ bfq_setup_cooperator(struct bfq_data *bfqd, struct bfq_queue *bfqq, { struct bfq_queue *in_service_bfqq, *new_bfqq;
- /* if a merge has already been setup, then proceed with that first */ - if (bfqq->new_bfqq) - return bfqq->new_bfqq; - /* * Do not perform queue merging if the device is non * rotational and performs internal queueing. In fact, such a @@ -2652,6 +2639,9 @@ bfq_setup_cooperator(struct bfq_data *bfqd, struct bfq_queue *bfqq, if (bfq_too_late_for_merging(bfqq)) return NULL;
+ if (bfqq->new_bfqq) + return bfqq->new_bfqq; + if (!io_struct || unlikely(bfqq == &bfqd->oom_bfqq)) return NULL;