Commit 721f076b authored by Breno Leitao's avatar Breno Leitao Committed by Jakub Kicinski
Browse files

net: dql: Optimize stall information population 



When Dynamic Queue Limit (DQL) is set, it always populate stall
information through dql_queue_stall().  However, this information is
only necessary if a stall threshold is set, stored in struct
dql->stall_thrs.

dql_queue_stall() is cheap, but not free, since it does have memory
barriers and so forth.

Do not call dql_queue_stall() if there is no stall threshold set, and
save some CPU cycles.

Signed-off-by: default avatarBreno Leitao <leitao@debian.org>
Link: https://lore.kernel.org/r/20240411192241.2498631-4-leitao@debian.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent cbe481a1

include/linux/dynamic_queue_limits.h

+3 −1
Original line number Diff line number Diff line
@@ -137,6 +137,8 @@ static inline void dql_queued(struct dql *dql, unsigned int count) 


	dql->num_queued += count;



	/* Only populate stall information if the threshold is set */

	if (READ_ONCE(dql->stall_thrs))

		dql_queue_stall(dql);

}