diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-08-30 19:30:30 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-08-30 19:30:30 -0700 |
commit | 3b629f8d6dc04d3af94429c18fe17239d6fbe2c3 (patch) | |
tree | f67dd6ef5c662927ee4c6533450c7b2c5724f69e /block | |
parent | c547d89a9a445f6bb757b93247de43d312e722da (diff) | |
parent | 3d5b3fbedad65088ec079a4c4d1a2f47e11ae1e7 (diff) |
Merge tag 'io_uring-bio-cache.5-2021-08-30' of git://git.kernel.dk/linux-block
Pull support for struct bio recycling from Jens Axboe:
"This adds bio recycling support for polled IO, allowing quick reuse of
a bio for high IOPS scenarios via a percpu bio_set list.
It's good for almost a 10% improvement in performance, bumping our
per-core IO limit from ~3.2M IOPS to ~3.5M IOPS"
* tag 'io_uring-bio-cache.5-2021-08-30' of git://git.kernel.dk/linux-block:
bio: improve kerneldoc documentation for bio_alloc_kiocb()
block: provide bio_clear_hipri() helper
block: use the percpu bio cache in __blkdev_direct_IO
io_uring: enable use of bio alloc cache
block: clear BIO_PERCPU_CACHE flag if polling isn't supported
bio: add allocation cache abstraction
fs: add kiocb alloc cache flag
bio: optimize initialization of a bio
Diffstat (limited to 'block')
-rw-r--r-- | block/bio.c | 169 | ||||
-rw-r--r-- | block/blk-core.c | 2 | ||||
-rw-r--r-- | block/blk-merge.c | 2 | ||||
-rw-r--r-- | block/blk.h | 7 |
4 files changed, 162 insertions, 18 deletions
diff --git a/block/bio.c b/block/bio.c index 265bff6b549a..1319dd2aa0b8 100644 --- a/block/bio.c +++ b/block/bio.c @@ -25,6 +25,11 @@ #include "blk.h" #include "blk-rq-qos.h" +struct bio_alloc_cache { + struct bio_list free_list; + unsigned int nr; +}; + static struct biovec_slab { int nr_vecs; char *name; @@ -246,12 +251,40 @@ static void bio_free(struct bio *bio) void bio_init(struct bio *bio, struct bio_vec *table, unsigned short max_vecs) { - memset(bio, 0, sizeof(*bio)); + bio->bi_next = NULL; + bio->bi_bdev = NULL; + bio->bi_opf = 0; + bio->bi_flags = 0; + bio->bi_ioprio = 0; + bio->bi_write_hint = 0; + bio->bi_status = 0; + bio->bi_iter.bi_sector = 0; + bio->bi_iter.bi_size = 0; + bio->bi_iter.bi_idx = 0; + bio->bi_iter.bi_bvec_done = 0; + bio->bi_end_io = NULL; + bio->bi_private = NULL; +#ifdef CONFIG_BLK_CGROUP + bio->bi_blkg = NULL; + bio->bi_issue.value = 0; +#ifdef CONFIG_BLK_CGROUP_IOCOST + bio->bi_iocost_cost = 0; +#endif +#endif +#ifdef CONFIG_BLK_INLINE_ENCRYPTION + bio->bi_crypt_context = NULL; +#endif +#ifdef CONFIG_BLK_DEV_INTEGRITY + bio->bi_integrity = NULL; +#endif + bio->bi_vcnt = 0; + atomic_set(&bio->__bi_remaining, 1); atomic_set(&bio->__bi_cnt, 1); - bio->bi_io_vec = table; bio->bi_max_vecs = max_vecs; + bio->bi_io_vec = table; + bio->bi_pool = NULL; } EXPORT_SYMBOL(bio_init); @@ -586,6 +619,53 @@ void guard_bio_eod(struct bio *bio) bio_truncate(bio, maxsector << 9); } +#define ALLOC_CACHE_MAX 512 +#define ALLOC_CACHE_SLACK 64 + +static void bio_alloc_cache_prune(struct bio_alloc_cache *cache, + unsigned int nr) +{ + unsigned int i = 0; + struct bio *bio; + + while ((bio = bio_list_pop(&cache->free_list)) != NULL) { + cache->nr--; + bio_free(bio); + if (++i == nr) + break; + } +} + +static int bio_cpu_dead(unsigned int cpu, struct hlist_node *node) +{ + struct bio_set *bs; + + bs = hlist_entry_safe(node, struct bio_set, cpuhp_dead); + if (bs->cache) { + struct bio_alloc_cache *cache = per_cpu_ptr(bs->cache, cpu); + + bio_alloc_cache_prune(cache, -1U); + } + return 0; +} + +static void bio_alloc_cache_destroy(struct bio_set *bs) +{ + int cpu; + + if (!bs->cache) + return; + + cpuhp_state_remove_instance_nocalls(CPUHP_BIO_DEAD, &bs->cpuhp_dead); + for_each_possible_cpu(cpu) { + struct bio_alloc_cache *cache; + + cache = per_cpu_ptr(bs->cache, cpu); + bio_alloc_cache_prune(cache, -1U); + } + free_percpu(bs->cache); +} + /** * bio_put - release a reference to a bio * @bio: bio to release reference to @@ -596,16 +676,23 @@ void guard_bio_eod(struct bio *bio) **/ void bio_put(struct bio *bio) { - if (!bio_flagged(bio, BIO_REFFED)) - bio_free(bio); - else { + if (unlikely(bio_flagged(bio, BIO_REFFED))) { BIO_BUG_ON(!atomic_read(&bio->__bi_cnt)); + if (!atomic_dec_and_test(&bio->__bi_cnt)) + return; + } - /* - * last put frees it - */ - if (atomic_dec_and_test(&bio->__bi_cnt)) - bio_free(bio); + if (bio_flagged(bio, BIO_PERCPU_CACHE)) { + struct bio_alloc_cache *cache; + + bio_uninit(bio); + cache = per_cpu_ptr(bio->bi_pool->cache, get_cpu()); + bio_list_add_head(&cache->free_list, bio); + if (++cache->nr > ALLOC_CACHE_MAX + ALLOC_CACHE_SLACK) + bio_alloc_cache_prune(cache, ALLOC_CACHE_SLACK); + put_cpu(); + } else { + bio_free(bio); } } EXPORT_SYMBOL(bio_put); @@ -1496,6 +1583,7 @@ int biovec_init_pool(mempool_t *pool, int pool_entries) */ void bioset_exit(struct bio_set *bs) { + bio_alloc_cache_destroy(bs); if (bs->rescue_workqueue) destroy_workqueue(bs->rescue_workqueue); bs->rescue_workqueue = NULL; @@ -1557,12 +1645,18 @@ int bioset_init(struct bio_set *bs, biovec_init_pool(&bs->bvec_pool, pool_size)) goto bad; - if (!(flags & BIOSET_NEED_RESCUER)) - return 0; - - bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0); - if (!bs->rescue_workqueue) - goto bad; + if (flags & BIOSET_NEED_RESCUER) { + bs->rescue_workqueue = alloc_workqueue("bioset", + WQ_MEM_RECLAIM, 0); + if (!bs->rescue_workqueue) + goto bad; + } + if (flags & BIOSET_PERCPU_CACHE) { + bs->cache = alloc_percpu(struct bio_alloc_cache); + if (!bs->cache) + goto bad; + cpuhp_state_add_instance_nocalls(CPUHP_BIO_DEAD, &bs->cpuhp_dead); + } return 0; bad: @@ -1589,6 +1683,46 @@ int bioset_init_from_src(struct bio_set *bs, struct bio_set *src) } EXPORT_SYMBOL(bioset_init_from_src); +/** + * bio_alloc_kiocb - Allocate a bio from bio_set based on kiocb + * @kiocb: kiocb describing the IO + * @nr_iovecs: number of iovecs to pre-allocate + * @bs: bio_set to allocate from + * + * Description: + * Like @bio_alloc_bioset, but pass in the kiocb. The kiocb is only + * used to check if we should dip into the per-cpu bio_set allocation + * cache. The allocation uses GFP_KERNEL internally. On return, the + * bio is marked BIO_PERCPU_CACHEABLE, and the final put of the bio + * MUST be done from process context, not hard/soft IRQ. + * + */ +struct bio *bio_alloc_kiocb(struct kiocb *kiocb, unsigned short nr_vecs, + struct bio_set *bs) +{ + struct bio_alloc_cache *cache; + struct bio *bio; + + if (!(kiocb->ki_flags & IOCB_ALLOC_CACHE) || nr_vecs > BIO_INLINE_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) { + cache->nr--; + put_cpu(); + bio_init(bio, nr_vecs ? bio->bi_inline_vecs : NULL, nr_vecs); + bio->bi_pool = bs; + bio_set_flag(bio, BIO_PERCPU_CACHE); + return bio; + } + put_cpu(); + bio = bio_alloc_bioset(GFP_KERNEL, nr_vecs, bs); + bio_set_flag(bio, BIO_PERCPU_CACHE); + return bio; +} +EXPORT_SYMBOL_GPL(bio_alloc_kiocb); + static int __init init_bio(void) { int i; @@ -1603,6 +1737,9 @@ static int __init init_bio(void) SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); } + cpuhp_setup_state_multi(CPUHP_BIO_DEAD, "block/bio:dead", NULL, + bio_cpu_dead); + if (bioset_init(&fs_bio_set, BIO_POOL_SIZE, 0, BIOSET_NEED_BVECS)) panic("bio: can't allocate bios\n"); diff --git a/block/blk-core.c b/block/blk-core.c index b5098739f72a..5454db2fa263 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -821,7 +821,7 @@ static noinline_for_stack bool submit_bio_checks(struct bio *bio) } if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags)) - bio->bi_opf &= ~REQ_HIPRI; + bio_clear_hipri(bio); switch (bio_op(bio)) { case REQ_OP_DISCARD: diff --git a/block/blk-merge.c b/block/blk-merge.c index eeba8422ae82..7a5c81c02c80 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -285,7 +285,7 @@ split: * iopoll in direct IO routine. Given performance gain of iopoll for * big IO can be trival, disable iopoll when split needed. */ - bio->bi_opf &= ~REQ_HIPRI; + bio_clear_hipri(bio); return bio_split(bio, sectors, GFP_NOIO, bs); } diff --git a/block/blk.h b/block/blk.h index 346d184c82b0..8c96b0c90c48 100644 --- a/block/blk.h +++ b/block/blk.h @@ -366,4 +366,11 @@ extern struct device_attribute dev_attr_events; extern struct device_attribute dev_attr_events_async; extern struct device_attribute dev_attr_events_poll_msecs; +static inline void bio_clear_hipri(struct bio *bio) +{ + /* can't support alloc cache if we turn off polling */ + bio_clear_flag(bio, BIO_PERCPU_CACHE); + bio->bi_opf &= ~REQ_HIPRI; +} + #endif /* BLK_INTERNAL_H */ |