lkml.org 
[lkml]   [2024]   [Apr]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH net-next v3 3/4] net: dql: Optimize stall information population
Date
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: Breno Leitao <leitao@debian.org>
---
include/linux/dynamic_queue_limits.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/include/linux/dynamic_queue_limits.h b/include/linux/dynamic_queue_limits.h
index 9980df0b7247..869afb800ea1 100644
--- a/include/linux/dynamic_queue_limits.h
+++ b/include/linux/dynamic_queue_limits.h
@@ -137,7 +137,9 @@ static inline void dql_queued(struct dql *dql, unsigned int count)

dql->num_queued += count;

- dql_queue_stall(dql);
+ /* Only populate stall information if the threshold is set */
+ if (READ_ONCE(dql->stall_thrs))
+ dql_queue_stall(dql);
}

/* Returns how many objects can be queued, < 0 indicates over limit. */
--
2.43.0

\
 
 \ /
  Last update: 2024-05-27 16:36    [W:0.036 / U:1.232 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site