| Message ID | 20211215163009.15269-3-axboe@kernel.dk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Improve IRQ driven performance | expand |
On Wed, Dec 15, 2021 at 09:30:08AM -0700, Jens Axboe wrote: > Pointless to maintain a head/tail for the list, as we never need to > access the tail. Entries are always LIFO for cache hotness reasons. > > Signed-off-by: Jens Axboe <axboe@kernel.dk> > --- > block/bio.c | 14 +++++++++----- > 1 file changed, 9 insertions(+), 5 deletions(-) > > diff --git a/block/bio.c b/block/bio.c > index d9d8e1143edc..a76a3134625a 100644 > --- a/block/bio.c > +++ b/block/bio.c > @@ -26,7 +26,7 @@ > #include "blk-rq-qos.h" > > struct bio_alloc_cache { > - struct bio_list free_list; > + struct bio *free_list; > unsigned int nr; > }; > > @@ -630,7 +630,9 @@ static void bio_alloc_cache_prune(struct bio_alloc_cache *cache, > unsigned int i = 0; > struct bio *bio; > > - while ((bio = bio_list_pop(&cache->free_list)) != NULL) { > + while (cache->free_list) { > + bio = cache->free_list; Nit: while ((bio = cache->free_list) != NULL) { would mke the iteration a litle more obvious. Otherwise looks good: Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/block/bio.c b/block/bio.c index d9d8e1143edc..a76a3134625a 100644 --- a/block/bio.c +++ b/block/bio.c @@ -26,7 +26,7 @@ #include "blk-rq-qos.h" struct bio_alloc_cache { - struct bio_list free_list; + struct bio *free_list; unsigned int nr; }; @@ -630,7 +630,9 @@ static void bio_alloc_cache_prune(struct bio_alloc_cache *cache, unsigned int i = 0; struct bio *bio; - while ((bio = bio_list_pop(&cache->free_list)) != NULL) { + while (cache->free_list) { + bio = cache->free_list; + cache->free_list = bio->bi_next; cache->nr--; bio_free(bio); if (++i == nr) @@ -689,7 +691,8 @@ void bio_put(struct bio *bio) bio_uninit(bio); cache = per_cpu_ptr(bio->bi_pool->cache, get_cpu()); - bio_list_add_head(&cache->free_list, bio); + bio->bi_next = cache->free_list; + cache->free_list = bio; if (++cache->nr > ALLOC_CACHE_MAX + ALLOC_CACHE_SLACK) bio_alloc_cache_prune(cache, ALLOC_CACHE_SLACK); put_cpu(); @@ -1700,8 +1703,9 @@ struct bio *bio_alloc_kiocb(struct kiocb *kiocb, unsigned short nr_vecs, return bio_alloc_bioset(GFP_KERNEL, nr_vecs, bs); cache = per_cpu_ptr(bs->cache, get_cpu()); - bio = bio_list_pop(&cache->free_list); - if (bio) { + if (cache->free_list) { + bio = cache->free_list; + cache->free_list = bio->bi_next; cache->nr--; put_cpu(); bio_init(bio, nr_vecs ? bio->bi_inline_vecs : NULL, nr_vecs);
Pointless to maintain a head/tail for the list, as we never need to access the tail. Entries are always LIFO for cache hotness reasons. Signed-off-by: Jens Axboe <axboe@kernel.dk> --- block/bio.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)