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block: don't check bio in blk_throtl_dispatch_work_fn 

The bio has been checked already before throttling, so no need to check
it again before dispatching it from throttle queue.

Add a helper of submit_bio_noacct_nocheck() for this purpose.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20220216044514.2903784-5-ming.lei@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Ming Lei 2022-02-16 12:45:10 +08:00 committed by Jens Axboe
parent 29ff23624e
commit 3f98c75371
3 changed files with 19 additions and 14 deletions
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30
block/blk-core.c
View File

@ -874,6 +874,22 @@ static void __submit_bio_noacct_mq(struct bio *bio)
current->bio_list = NULL;
}
void submit_bio_noacct_nocheck(struct bio *bio)
{
/*
* We only want one ->submit_bio to be active at a time, else stack
* usage with stacked devices could be a problem. Use current->bio_list
* to collect a list of requests submited by a ->submit_bio method while
* it is active, and then process them after it returned.
*/
if (current->bio_list)
bio_list_add(&current->bio_list[0], bio);
else if (!bio->bi_bdev->bd_disk->fops->submit_bio)
__submit_bio_noacct_mq(bio);
else
__submit_bio_noacct(bio);
}
/**
* submit_bio_noacct - re-submit a bio to the block device layer for I/O
* @bio: The bio describing the location in memory and on the device.
@ -887,19 +903,7 @@ void submit_bio_noacct(struct bio *bio)
{
if (unlikely(!submit_bio_checks(bio)))
return;
/*
* We only want one ->submit_bio to be active at a time, else stack
* usage with stacked devices could be a problem. Use current->bio_list
* to collect a list of requests submited by a ->submit_bio method while
* it is active, and then process them after it returned.
*/
if (current->bio_list)
bio_list_add(&current->bio_list[0], bio);
else if (!bio->bi_bdev->bd_disk->fops->submit_bio)
__submit_bio_noacct_mq(bio);
else
__submit_bio_noacct(bio);
submit_bio_noacct_nocheck(bio);
}
EXPORT_SYMBOL(submit_bio_noacct);

2
block/blk-throttle.c
View File

@ -1218,7 +1218,7 @@ static void blk_throtl_dispatch_work_fn(struct work_struct *work)
if (!bio_list_empty(&bio_list_on_stack)) {
blk_start_plug(&plug);
while ((bio = bio_list_pop(&bio_list_on_stack)))
submit_bio_noacct(bio);
submit_bio_noacct_nocheck(bio);
blk_finish_plug(&plug);
}
}

1
block/blk.h
View File

@ -46,6 +46,7 @@ void blk_freeze_queue(struct request_queue *q);
void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic);
void blk_queue_start_drain(struct request_queue *q);
int __bio_queue_enter(struct request_queue *q, struct bio *bio);
void submit_bio_noacct_nocheck(struct bio *bio);
static inline bool blk_try_enter_queue(struct request_queue *q, bool pm)
{