From 3c1c875d058669b4dee68f877ec8a65ad4ae8b5b Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Mon, 25 Jul 2022 18:26:48 -0400 Subject: [PATCH] dm bufio: conditionally enable branching for DM_BUFIO_CLIENT_NO_SLEEP Use jump_label to limit the need for branching unless the optional DM_BUFIO_CLIENT_NO_SLEEP is used. Signed-off-by: Mike Snitzer --- drivers/md/dm-bufio.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c index 486179d..0a38a7a 100644 --- a/drivers/md/dm-bufio.c +++ b/drivers/md/dm-bufio.c @@ -18,6 +18,7 @@ #include #include #include +#include #define DM_MSG_PREFIX "bufio" @@ -164,13 +165,15 @@ struct dm_buffer { #endif }; +static DEFINE_STATIC_KEY_FALSE(no_sleep_enabled); + /*----------------------------------------------------------------*/ #define dm_bufio_in_request() (!!current->bio_list) static void dm_bufio_lock(struct dm_bufio_client *c) { - if (c->no_sleep) + if (static_branch_unlikely(&no_sleep_enabled) && c->no_sleep) spin_lock_irqsave_nested(&c->spinlock, c->spinlock_flags, dm_bufio_in_request()); else mutex_lock_nested(&c->lock, dm_bufio_in_request()); @@ -178,7 +181,7 @@ static void dm_bufio_lock(struct dm_bufio_client *c) static int dm_bufio_trylock(struct dm_bufio_client *c) { - if (c->no_sleep) + if (static_branch_unlikely(&no_sleep_enabled) && c->no_sleep) return spin_trylock_irqsave(&c->spinlock, c->spinlock_flags); else return mutex_trylock(&c->lock); @@ -186,7 +189,7 @@ static int dm_bufio_trylock(struct dm_bufio_client *c) static void dm_bufio_unlock(struct dm_bufio_client *c) { - if (c->no_sleep) + if (static_branch_unlikely(&no_sleep_enabled) && c->no_sleep) spin_unlock_irqrestore(&c->spinlock, c->spinlock_flags); else mutex_unlock(&c->lock); @@ -1760,8 +1763,10 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign c->alloc_callback = alloc_callback; c->write_callback = write_callback; - if (flags & DM_BUFIO_CLIENT_NO_SLEEP) + if (flags & DM_BUFIO_CLIENT_NO_SLEEP) { c->no_sleep = true; + static_branch_inc(&no_sleep_enabled); + } for (i = 0; i < LIST_SIZE; i++) { INIT_LIST_HEAD(&c->lru[i]); @@ -1895,6 +1900,8 @@ void dm_bufio_client_destroy(struct dm_bufio_client *c) kmem_cache_destroy(c->slab_buffer); dm_io_client_destroy(c->dm_io); mutex_destroy(&c->lock); + if (c->no_sleep) + static_branch_dec(&no_sleep_enabled); kfree(c); } EXPORT_SYMBOL_GPL(dm_bufio_client_destroy); -- 2.7.4