diff mbox series

dql: Fix dql->limit value when reset.

Message ID Z9qHD1s/NEuQBdgH@pilot-ThinkCentre-M930t-N000 (mailing list archive)
State Under Review
Delegated to: Netdev Maintainers
Headers show
Series dql: Fix dql->limit value when reset. | expand

Checks

Context Check Description
netdev/series_format warning Single patches do not need cover letters; Target tree name not specified in the subject
netdev/tree_selection success Guessed tree name to be 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: 0 this patch: 0
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers fail 1 maintainers not CCed: akpm@linux-foundation.org
netdev/build_clang success Errors and warnings before: 0 this patch: 0
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: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 8 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 fail net-next-2025-03-19--12-00 (tests: 895)

Commit Message

Jing Su March 19, 2025, 8:57 a.m. UTC
Executing dql_reset after setting a non-zero value for limit_min can
lead to an unreasonable situation where dql->limit is less than
dql->limit_min.

For instance, after setting
/sys/class/net/eth*/queues/tx-0/byte_queue_limits/limit_min,
an ifconfig down/up operation might cause the ethernet driver to call
netdev_tx_reset_queue, which in turn invokes dql_reset.

In this case, dql->limit is reset to 0 while dql->limit_min remains
non-zero value, which is unexpected. The limit should always be
greater than or equal to limit_min.

Signed-off-by: Jing Su <jingsusu@didiglobal.com>
---
 lib/dynamic_queue_limits.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/lib/dynamic_queue_limits.c b/lib/dynamic_queue_limits.c
index c1b7638a594a..f97a752e900a 100644
--- a/lib/dynamic_queue_limits.c
+++ b/lib/dynamic_queue_limits.c
@@ -190,7 +190,7 @@  EXPORT_SYMBOL(dql_completed);
 void dql_reset(struct dql *dql)
 {
 	/* Reset all dynamic values */
-	dql->limit = 0;
+	dql->limit = dql->min_limit;
 	dql->num_queued = 0;
 	dql->num_completed = 0;
 	dql->last_obj_cnt = 0;