Commit 3a17f23f authored by Jing Su's avatar Jing Su Committed by Jakub Kicinski
Browse files

dql: Fix dql->limit value when reset. 



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: default avatarJing Su <jingsusu@didiglobal.com>
Link: https://patch.msgid.link/Z9qHD1s/NEuQBdgH@pilot-ThinkCentre-M930t-N000


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 45e36a8e

lib/dynamic_queue_limits.c

+1 −1
Original line number Diff line number Diff line
@@ -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;