| Message ID | 20230714143014.11879-1-hch@lst.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | block: queue data commands from the flush state machine at the head | expand |
On Fri, 14 Jul 2023 16:30:14 +0200, Christoph Hellwig wrote: > 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. > > [...] Applied, thanks! [1/1] block: queue data commands from the flush state machine at the head commit: 9f87fc4d72f52b26ac3e19df5e4584227fe6740c Best regards,
diff --git a/block/blk-flush.c b/block/blk-flush.c index dba392cf22bec6..8220517c2d67da 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;
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> --- block/blk-flush.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)