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| author | Muchun Song <songmuchun@bytedance.com> | 2024-10-21 16:52:51 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2024-10-22 14:05:09 -0600 |
| commit | 904ebd2527c507752f5ddb358f887d2e0dab96a0 (patch) | |
| tree | f4cd4b31081fec8d39137824defffcfd50ca5dcb /block | |
| parent | fdad1a20cd57bff65539d971c0ec74faf2b5b2fc (diff) | |
| download | lwn-904ebd2527c507752f5ddb358f887d2e0dab96a0.tar.gz lwn-904ebd2527c507752f5ddb358f887d2e0dab96a0.zip | |
block: remove redundant explicit memory barrier from rq_qos waiter and waker
The memory barriers in list_del_init_careful() and list_empty_careful()
in pairs already handle the proper ordering between data.got_token
and data.wq.entry. So remove the redundant explicit barriers. And also
change a "break" statement to "return" to avoid redundant calling of
finish_wait().
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Link: https://lore.kernel.org/r/20241021085251.73353-1-songmuchun@bytedance.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-rq-qos.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c index 058f92c4f9d5..eb9618cd68ad 100644 --- a/block/blk-rq-qos.c +++ b/block/blk-rq-qos.c @@ -218,7 +218,6 @@ static int rq_qos_wake_function(struct wait_queue_entry *curr, return -1; data->got_token = true; - smp_wmb(); wake_up_process(data->task); list_del_init_careful(&curr->entry); return 1; @@ -274,10 +273,9 @@ void rq_qos_wait(struct rq_wait *rqw, void *private_data, * which means we now have two. Put our local token * and wake anyone else potentially waiting for one. */ - smp_rmb(); if (data.got_token) cleanup_cb(rqw, private_data); - break; + return; } io_schedule(); has_sleeper = true; |