block: enable per-cpu bio caching for the fs bio set

This is useful for polled IO on a file, or for polled IO with the
io_uring passthrough mechanism. If bio allocations are done with
REQ_POLLED for those cases, then initializing the bio set with
BIOSET_PERCPU_CACHE enables the local per-cpu cache which eliminates
allocations (and frees) of bio structs when possible.

Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/bio.c b/block/bio.c
index 3d3a267..d3154d8 100644 (file)
--- a/block/bio.c
+++ b/block/bio.c
@@ -1754,7 +1754,8 @@ static int __init init_bio(void)
        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))
+       if (bioset_init(&fs_bio_set, BIO_POOL_SIZE, 0,
+                       BIOSET_NEED_BVECS | BIOSET_PERCPU_CACHE))
                panic("bio: can't allocate bios\n");
 
        if (bioset_integrity_create(&fs_bio_set, BIO_POOL_SIZE))