Commit 2d8f7a3b authored by Yu Kuai's avatar Yu Kuai Committed by Jens Axboe
Browse files

blk-throttle: clean up codes that can't be reached 



While doing code coverage testing while CONFIG_BLK_DEV_THROTTLING_LOW is
disabled, we found that there are many codes can never be reached.

This patch move such codes inside "#ifdef CONFIG_BLK_DEV_THROTTLING_LOW".

Signed-off-by: default avatarYu Kuai <yukuai3@huawei.com>
Acked-by: default avatarTejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220903062826.1099085-1-yukuai1@huaweicloud.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent bce1b56c

block/blk-throttle.c

+56 −34
Original line number Diff line number Diff line
@@ -1673,6 +1673,40 @@ struct blkcg_policy blkcg_policy_throtl = { 
	.pd_free_fn		= throtl_pd_free,

};



void blk_throtl_cancel_bios(struct request_queue *q)

{

	struct cgroup_subsys_state *pos_css;

	struct blkcg_gq *blkg;



	spin_lock_irq(&q->queue_lock);

	/*

	 * queue_lock is held, rcu lock is not needed here technically.

	 * However, rcu lock is still held to emphasize that following

	 * path need RCU protection and to prevent warning from lockdep.

	 */

	rcu_read_lock();

	blkg_for_each_descendant_post(blkg, pos_css, q->root_blkg) {

		struct throtl_grp *tg = blkg_to_tg(blkg);

		struct throtl_service_queue *sq = &tg->service_queue;



		/*

		 * Set the flag to make sure throtl_pending_timer_fn() won't

		 * stop until all throttled bios are dispatched.

		 */

		blkg_to_tg(blkg)->flags |= THROTL_TG_CANCELING;

		/*

		 * Update disptime after setting the above flag to make sure

		 * throtl_select_dispatch() won't exit without dispatching.

		 */

		tg_update_disptime(tg);



		throtl_schedule_pending_timer(sq, jiffies + 1);

	}

	rcu_read_unlock();

	spin_unlock_irq(&q->queue_lock);

}



#ifdef CONFIG_BLK_DEV_THROTTLING_LOW

static unsigned long __tg_last_low_overflow_time(struct throtl_grp *tg)

{

	unsigned long rtime = jiffies, wtime = jiffies;
@@ -1777,39 +1811,6 @@ static bool throtl_hierarchy_can_upgrade(struct throtl_grp *tg) 
	return false;

}



void blk_throtl_cancel_bios(struct request_queue *q)

{

	struct cgroup_subsys_state *pos_css;

	struct blkcg_gq *blkg;



	spin_lock_irq(&q->queue_lock);

	/*

	 * queue_lock is held, rcu lock is not needed here technically.

	 * However, rcu lock is still held to emphasize that following

	 * path need RCU protection and to prevent warning from lockdep.

	 */

	rcu_read_lock();

	blkg_for_each_descendant_post(blkg, pos_css, q->root_blkg) {

		struct throtl_grp *tg = blkg_to_tg(blkg);

		struct throtl_service_queue *sq = &tg->service_queue;



		/*

		 * Set the flag to make sure throtl_pending_timer_fn() won't

		 * stop until all throttled bios are dispatched.

		 */

		blkg_to_tg(blkg)->flags |= THROTL_TG_CANCELING;

		/*

		 * Update disptime after setting the above flag to make sure

		 * throtl_select_dispatch() won't exit without dispatching.

		 */

		tg_update_disptime(tg);



		throtl_schedule_pending_timer(sq, jiffies + 1);

	}

	rcu_read_unlock();

	spin_unlock_irq(&q->queue_lock);

}



static bool throtl_can_upgrade(struct throtl_data *td,

	struct throtl_grp *this_tg)

{
@@ -2005,7 +2006,6 @@ static void blk_throtl_update_idletime(struct throtl_grp *tg) 
	tg->checked_last_finish_time = last_finish_time;

}



#ifdef CONFIG_BLK_DEV_THROTTLING_LOW

static void throtl_update_latency_buckets(struct throtl_data *td)

{

	struct avg_latency_bucket avg_latency[2][LATENCY_BUCKET_SIZE];
@@ -2086,6 +2086,28 @@ static void throtl_update_latency_buckets(struct throtl_data *td) 
static inline void throtl_update_latency_buckets(struct throtl_data *td)

{

}



static void blk_throtl_update_idletime(struct throtl_grp *tg)

{

}



static void throtl_downgrade_check(struct throtl_grp *tg)

{

}



static void throtl_upgrade_check(struct throtl_grp *tg)

{

}



static bool throtl_can_upgrade(struct throtl_data *td,

	struct throtl_grp *this_tg)

{

	return false;

}



static void throtl_upgrade_state(struct throtl_data *td)

{

}

#endif



bool __blk_throtl_bio(struct bio *bio)