diff --git a/block/bio.c b/block/bio.c
index 6fa5c653283b68224f0209571b0b3046c5ce066a..dbb0bc8e1ef776eaae22f51f0c9175e7e60346ae 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;
@@ -619,6 +624,53 @@ 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
@@ -629,16 +681,23 @@ 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);
@@ -1530,6 +1589,7 @@ 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;
@@ -1591,12 +1651,18 @@ 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:
@@ -1623,6 +1689,43 @@ 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
+ * @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.
+ *
+ */
+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;
@@ -1637,6 +1740,9 @@ 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/include/linux/bio.h b/include/linux/bio.h
index 2203b686e1f03432fc36ca7873cafed81be29da6..89ad28213b1d601467146ca095121618d3c00e7d 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -401,6 +401,7 @@ static inline struct bio *bio_next_split(struct bio *bio, int sectors,
enum {
BIOSET_NEED_BVECS = BIT(0),
BIOSET_NEED_RESCUER = BIT(1),
+ BIOSET_PERCPU_CACHE = BIT(2),
};
extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);
extern void bioset_exit(struct bio_set *);
@@ -409,6 +410,8 @@ extern int bioset_init_from_src(struct bio_set *bs, struct bio_set *src);
struct bio *bio_alloc_bioset(gfp_t gfp, unsigned short nr_iovecs,
struct bio_set *bs);
+struct bio *bio_alloc_kiocb(struct kiocb *kiocb, unsigned short nr_vecs,
+ struct bio_set *bs);
struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned short nr_iovecs);
extern void bio_put(struct bio *);
@@ -699,6 +702,11 @@ struct bio_set {
struct kmem_cache *bio_slab;
unsigned int front_pad;
+ /*
+ * per-cpu bio alloc cache
+ */
+ struct bio_alloc_cache __percpu *cache;
+
mempool_t bio_pool;
mempool_t bvec_pool;
#if defined(CONFIG_BLK_DEV_INTEGRITY)
@@ -715,6 +723,11 @@ struct bio_set {
struct bio_list rescue_list;
struct work_struct rescue_work;
struct workqueue_struct *rescue_workqueue;
+
+ /*
+ * Hot un-plug notifier for the per-cpu cache, if used
+ */
+ struct hlist_node cpuhp_dead;
};
static inline bool bioset_initialized(struct bio_set *bs)
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 290f9061b29ac8d62febda52f3f7c69f9fed6372..f68d4e8c775e81dca6e76979956c57293ed71e0a 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -301,6 +301,7 @@ enum {
BIO_TRACKED, /* set if bio goes through the rq_qos path */
BIO_REMAPPED,
BIO_ZONE_WRITE_LOCKED, /* Owns a zoned device zone write lock */
+ BIO_PERCPU_CACHE, /* can participate in per-cpu alloc cache */
BIO_FLAG_LAST
};
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index f39b34b138710985305ff645f6e89c08c311dc6c..fe72c8d6c9809a2a5a8d4ac777f96f5f5656db39 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -46,6 +46,7 @@ enum cpuhp_state {
CPUHP_ARM_OMAP_WAKE_DEAD,
CPUHP_IRQ_POLL_DEAD,
CPUHP_BLOCK_SOFTIRQ_DEAD,
+ CPUHP_BIO_DEAD,
CPUHP_ACPI_CPUDRV_DEAD,
CPUHP_S390_PFAULT_DEAD,
CPUHP_BLK_MQ_DEAD,