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| author | Christoph Hellwig <hch@lst.de> | 2023-07-14 16:30:14 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2023-07-14 08:42:58 -0600 |
| commit | 9f87fc4d72f52b26ac3e19df5e4584227fe6740c (patch) | |
| tree | 58169b545b6aa86d4c746668169d64bcd24cf86d | |
| parent | 90b4622954d59078fa0cecad7e7baa48efd006e7 (diff) | |
| download | lwn-9f87fc4d72f52b26ac3e19df5e4584227fe6740c.tar.gz lwn-9f87fc4d72f52b26ac3e19df5e4584227fe6740c.zip | |
block: queue data commands from the flush state machine at the head
We used to insert the data commands following a pre-flush to the head
of the queue until commit 1e82fadfc6b ("blk-mq: do not do head insertions
post-pre-flush commands"). Not doing this seems to cause hangs of
such commands on NFS workloads when exported from file systems with
SATA SSDs. I have no idea why this would starve these workloads,
but doing a semantic revert of this patch (which looks quite different
due to various other changes) fixes the hangs.
Fixes: 1e82fadfc6b ("blk-mq: do not do head insertions post-pre-flush commands")
Reported-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://lore.kernel.org/r/20230714143014.11879-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | block/blk-flush.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/block/blk-flush.c b/block/blk-flush.c index dba392cf22be..8220517c2d67 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -189,7 +189,7 @@ static void blk_flush_complete_seq(struct request *rq, case REQ_FSEQ_DATA: list_move_tail(&rq->flush.list, &fq->flush_data_in_flight); spin_lock(&q->requeue_lock); - list_add_tail(&rq->queuelist, &q->flush_list); + list_add(&rq->queuelist, &q->requeue_list); spin_unlock(&q->requeue_lock); blk_mq_kick_requeue_list(q); break; |