diff mbox series

[net-next,v3,3/4] net: dql: Optimize stall information population

Message ID 20240411192241.2498631-4-leitao@debian.org (mailing list archive)
State Accepted
Commit 721f076b62cb05108565adf17c27875ef5015307
Delegated to: Netdev Maintainers
Headers show
Series net: dqs: optimize if stall threshold is not set | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 4856 this patch: 4856
netdev/build_tools success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers success CCed 2 of 2 maintainers
netdev/build_clang success Errors and warnings before: 1056 this patch: 1056
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 5132 this patch: 5132
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 10 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-04-12--06-00 (tests: 962)

Commit Message

Breno Leitao April 11, 2024, 7:22 p.m. UTC
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 mbox series

Patch

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. */