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block: remove redundant explicit memory barrier from rq_qos waiter and waker

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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>
This commit is contained in:
Muchun Song 2024-10-21 16:52:51 +08:00 committed by Jens Axboe
parent fdad1a20cd
commit 904ebd2527
1 changed files with 1 additions and 3 deletions
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4
block/blk-rq-qos.c
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@ -218,7 +218,6 @@ static int rq_qos_wake_function(struct wait_queue_entry *curr,
return -1; return -1;
data->got_token = true; data->got_token = true;
smp_wmb();
wake_up_process(data->task); wake_up_process(data->task);
list_del_init_careful(&curr->entry); list_del_init_careful(&curr->entry);
return 1; 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 * which means we now have two. Put our local token
* and wake anyone else potentially waiting for one. * and wake anyone else potentially waiting for one.
*/ */
smp_rmb();
if (data.got_token) if (data.got_token)
cleanup_cb(rqw, private_data); cleanup_cb(rqw, private_data);
break; return;
} }
io_schedule(); io_schedule();
has_sleeper = true; has_sleeper = true;