| Message ID | 20211013164937.985367-2-axboe@kernel.dk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Various block optimizations | expand |
On Wed, Oct 13, 2021 at 10:49:34AM -0600, Jens Axboe wrote: > Instead of open-coding the list additions, traversal, and removal, > provide a basic set of helpers. > > Suggested-by: Christoph Hellwig <hch@infradead.org> > Signed-off-by: Jens Axboe <axboe@kernel.dk> > --- > block/blk-mq.c | 21 +++++---------------- > include/linux/blk-mq.h | 25 +++++++++++++++++++++++++ > 2 files changed, 30 insertions(+), 16 deletions(-) > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index 6dfd3aaa6073..46a91e5fabc5 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -426,10 +426,10 @@ static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data) > tag = tag_offset + i; > tags &= ~(1UL << i); > rq = blk_mq_rq_ctx_init(data, tag, alloc_time_ns); > - rq->rq_next = *data->cached_rq; > - *data->cached_rq = rq; > + rq_list_add_tail(data->cached_rq, rq); > } This doesn't seem to match the code in the current for-5.6/block branch. > data->nr_tags -= nr; > + return rq_list_pop(data->cached_rq); > } else { But either way no need for an else after a return.
On 10/13/21 11:11 AM, Christoph Hellwig wrote: > On Wed, Oct 13, 2021 at 10:49:34AM -0600, Jens Axboe wrote: >> Instead of open-coding the list additions, traversal, and removal, >> provide a basic set of helpers. >> >> Suggested-by: Christoph Hellwig <hch@infradead.org> >> Signed-off-by: Jens Axboe <axboe@kernel.dk> >> --- >> block/blk-mq.c | 21 +++++---------------- >> include/linux/blk-mq.h | 25 +++++++++++++++++++++++++ >> 2 files changed, 30 insertions(+), 16 deletions(-) >> >> diff --git a/block/blk-mq.c b/block/blk-mq.c >> index 6dfd3aaa6073..46a91e5fabc5 100644 >> --- a/block/blk-mq.c >> +++ b/block/blk-mq.c >> @@ -426,10 +426,10 @@ static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data) >> tag = tag_offset + i; >> tags &= ~(1UL << i); >> rq = blk_mq_rq_ctx_init(data, tag, alloc_time_ns); >> - rq->rq_next = *data->cached_rq; >> - *data->cached_rq = rq; >> + rq_list_add_tail(data->cached_rq, rq); >> } > > This doesn't seem to match the code in the current for-5.6/block branch. It's after the 2 patch improvement series. >> data->nr_tags -= nr; >> + return rq_list_pop(data->cached_rq); >> } else { > > But either way no need for an else after a return. We can kill that, but it's really independent and unrelated to this patch.
diff --git a/block/blk-mq.c b/block/blk-mq.c index 6dfd3aaa6073..46a91e5fabc5 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -426,10 +426,10 @@ static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data) tag = tag_offset + i; tags &= ~(1UL << i); rq = blk_mq_rq_ctx_init(data, tag, alloc_time_ns); - rq->rq_next = *data->cached_rq; - *data->cached_rq = rq; + rq_list_add_tail(data->cached_rq, rq); } data->nr_tags -= nr; + return rq_list_pop(data->cached_rq); } else { /* * Waiting allocations only fail because of an inactive hctx. @@ -453,14 +453,6 @@ static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data) return blk_mq_rq_ctx_init(data, tag, alloc_time_ns); } - - if (data->cached_rq) { - rq = *data->cached_rq; - *data->cached_rq = rq->rq_next; - return rq; - } - - return NULL; } struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op, @@ -603,11 +595,9 @@ EXPORT_SYMBOL_GPL(blk_mq_free_request); void blk_mq_free_plug_rqs(struct blk_plug *plug) { - while (plug->cached_rq) { - struct request *rq; + struct request *rq; - rq = plug->cached_rq; - plug->cached_rq = rq->rq_next; + while ((rq = rq_list_pop(&plug->cached_rq)) != NULL) { percpu_ref_get(&rq->q->q_usage_counter); blk_mq_free_request(rq); } @@ -2264,8 +2254,7 @@ void blk_mq_submit_bio(struct bio *bio) plug = blk_mq_plug(q, bio); if (plug && plug->cached_rq) { - rq = plug->cached_rq; - plug->cached_rq = rq->rq_next; + rq = rq_list_pop(&plug->cached_rq); INIT_LIST_HEAD(&rq->queuelist); } else { struct blk_mq_alloc_data data = { diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h index a9c1d0882550..c05560524841 100644 --- a/include/linux/blk-mq.h +++ b/include/linux/blk-mq.h @@ -473,6 +473,31 @@ struct blk_mq_tag_set { struct list_head tag_list; }; +#define rq_list_add_tail(listptr, rq) do { \ + (rq)->rq_next = *(listptr); \ + *(listptr) = rq; \ +} while (0) + +#define rq_list_pop(listptr) \ +({ \ + struct request *__req = NULL; \ + if ((listptr) && *(listptr)) { \ + __req = *(listptr); \ + *(listptr) = __req->rq_next; \ + } \ + __req; \ +}) + +#define rq_list_peek(listptr) \ +({ \ + struct request *__req = NULL; \ + if ((listptr) && *(listptr)) \ + __req = *(listptr); \ + __req; \ +}) + +#define rq_list_next(rq) (rq)->rq_next + /** * struct blk_mq_queue_data - Data about a request inserted in a queue *
Instead of open-coding the list additions, traversal, and removal, provide a basic set of helpers. Suggested-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk> --- block/blk-mq.c | 21 +++++---------------- include/linux/blk-mq.h | 25 +++++++++++++++++++++++++ 2 files changed, 30 insertions(+), 16 deletions(-)