| Message ID | 20230629110359.1111832-3-chengming.zhou@linux.dev (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | blk-mq: optimize the size of struct request | expand |
On Thu, Jun 29, 2023 at 07:03:57PM +0800, chengming.zhou@linux.dev wrote: > From: Chengming Zhou <zhouchengming@bytedance.com> > > The flush state machine use a double list to link all inflight > flush_data requests, to avoid issuing separate post-flushes for > these flush_data requests which shared PREFLUSH. > > So we can't reuse rq->queuelist, this is why we need rq->flush.list > > In preparation of the next patch that reuse rq->queuelist for flush > state machine, we change the double linked list to unsigned long > counter, which count all inflight flush_data requests. > > This is ok since we only need to know if there is any inflight > flush_data request, so unsigned long counter is good. > > Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> > --- > block/blk-flush.c | 9 +++++---- > block/blk.h | 5 ++--- > 2 files changed, 7 insertions(+), 7 deletions(-) > > diff --git a/block/blk-flush.c b/block/blk-flush.c > index dba392cf22be..bb7adfc2a5da 100644 > --- a/block/blk-flush.c > +++ b/block/blk-flush.c > @@ -187,7 +187,8 @@ static void blk_flush_complete_seq(struct request *rq, > break; > > case REQ_FSEQ_DATA: > - list_move_tail(&rq->flush.list, &fq->flush_data_in_flight); > + list_del_init(&rq->flush.list); > + fq->flush_data_in_flight++; > spin_lock(&q->requeue_lock); > list_add_tail(&rq->queuelist, &q->flush_list); > spin_unlock(&q->requeue_lock); > @@ -299,7 +300,7 @@ static void blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq, > return; > > /* C2 and C3 */ > - if (!list_empty(&fq->flush_data_in_flight) && > + if (fq->flush_data_in_flight && > time_before(jiffies, > fq->flush_pending_since + FLUSH_PENDING_TIMEOUT)) > return; > @@ -374,6 +375,7 @@ static enum rq_end_io_ret mq_flush_data_end_io(struct request *rq, > * the comment in flush_end_io(). > */ > spin_lock_irqsave(&fq->mq_flush_lock, flags); > + fq->flush_data_in_flight--; > blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error); > spin_unlock_irqrestore(&fq->mq_flush_lock, flags); > > @@ -445,7 +447,7 @@ bool blk_insert_flush(struct request *rq) > blk_rq_init_flush(rq); > rq->flush.seq |= REQ_FSEQ_POSTFLUSH; > spin_lock_irq(&fq->mq_flush_lock); > - list_move_tail(&rq->flush.list, &fq->flush_data_in_flight); > + fq->flush_data_in_flight++; > spin_unlock_irq(&fq->mq_flush_lock); > return false; > default: > @@ -496,7 +498,6 @@ struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size, > > INIT_LIST_HEAD(&fq->flush_queue[0]); > INIT_LIST_HEAD(&fq->flush_queue[1]); > - INIT_LIST_HEAD(&fq->flush_data_in_flight); > > return fq; > > diff --git a/block/blk.h b/block/blk.h > index 608c5dcc516b..686712e13835 100644 > --- a/block/blk.h > +++ b/block/blk.h > @@ -15,15 +15,14 @@ struct elevator_type; > extern struct dentry *blk_debugfs_root; > > struct blk_flush_queue { > + spinlock_t mq_flush_lock; > unsigned int flush_pending_idx:1; > unsigned int flush_running_idx:1; > blk_status_t rq_status; > unsigned long flush_pending_since; > struct list_head flush_queue[2]; > - struct list_head flush_data_in_flight; > + unsigned long flush_data_in_flight; > struct request *flush_rq; > - > - spinlock_t mq_flush_lock; Looks fine, Reviewed-by: Ming Lei <ming.lei@redhat.com> Thanks, Ming
Looks good:
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/block/blk-flush.c b/block/blk-flush.c index dba392cf22be..bb7adfc2a5da 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -187,7 +187,8 @@ static void blk_flush_complete_seq(struct request *rq, break; case REQ_FSEQ_DATA: - list_move_tail(&rq->flush.list, &fq->flush_data_in_flight); + list_del_init(&rq->flush.list); + fq->flush_data_in_flight++; spin_lock(&q->requeue_lock); list_add_tail(&rq->queuelist, &q->flush_list); spin_unlock(&q->requeue_lock); @@ -299,7 +300,7 @@ static void blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq, return; /* C2 and C3 */ - if (!list_empty(&fq->flush_data_in_flight) && + if (fq->flush_data_in_flight && time_before(jiffies, fq->flush_pending_since + FLUSH_PENDING_TIMEOUT)) return; @@ -374,6 +375,7 @@ static enum rq_end_io_ret mq_flush_data_end_io(struct request *rq, * the comment in flush_end_io(). */ spin_lock_irqsave(&fq->mq_flush_lock, flags); + fq->flush_data_in_flight--; blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error); spin_unlock_irqrestore(&fq->mq_flush_lock, flags); @@ -445,7 +447,7 @@ bool blk_insert_flush(struct request *rq) blk_rq_init_flush(rq); rq->flush.seq |= REQ_FSEQ_POSTFLUSH; spin_lock_irq(&fq->mq_flush_lock); - list_move_tail(&rq->flush.list, &fq->flush_data_in_flight); + fq->flush_data_in_flight++; spin_unlock_irq(&fq->mq_flush_lock); return false; default: @@ -496,7 +498,6 @@ struct blk_flush_queue *blk_alloc_flush_queue(int node, int cmd_size, INIT_LIST_HEAD(&fq->flush_queue[0]); INIT_LIST_HEAD(&fq->flush_queue[1]); - INIT_LIST_HEAD(&fq->flush_data_in_flight); return fq; diff --git a/block/blk.h b/block/blk.h index 608c5dcc516b..686712e13835 100644 --- a/block/blk.h +++ b/block/blk.h @@ -15,15 +15,14 @@ struct elevator_type; extern struct dentry *blk_debugfs_root; struct blk_flush_queue { + spinlock_t mq_flush_lock; unsigned int flush_pending_idx:1; unsigned int flush_running_idx:1; blk_status_t rq_status; unsigned long flush_pending_since; struct list_head flush_queue[2]; - struct list_head flush_data_in_flight; + unsigned long flush_data_in_flight; struct request *flush_rq; - - spinlock_t mq_flush_lock; }; bool is_flush_rq(struct request *req);