net: sched: red: delay destroying child qdisc on replace

Move destroying of the old child qdisc outside of the sch_tree_lock()
section.  This should improve the software qdisc replace but is even
more important for offloads.  Firstly calling offloads under a spin
lock is best avoided.  Secondly the destroy event of existing child
would have been sent to the offload device before the replace, causing
confusion.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jakub Kicinski 2018-11-07 17:33:39 -08:00 committed by David S. Miller
parent 9da93ece59
commit 0c8d13ac96

View File

@ -193,10 +193,10 @@ static const struct nla_policy red_policy[TCA_RED_MAX + 1] = {
static int red_change(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
struct Qdisc *old_child = NULL, *child = NULL;
struct red_sched_data *q = qdisc_priv(sch);
struct nlattr *tb[TCA_RED_MAX + 1];
struct tc_red_qopt *ctl;
struct Qdisc *child = NULL;
int err;
u32 max_P;
@ -233,7 +233,7 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt,
if (child) {
qdisc_tree_reduce_backlog(q->qdisc, q->qdisc->q.qlen,
q->qdisc->qstats.backlog);
qdisc_put(q->qdisc);
old_child = q->qdisc;
q->qdisc = child;
}
@ -252,7 +252,11 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt,
red_start_of_idle_period(&q->vars);
sch_tree_unlock(sch);
red_offload(sch, true);
if (old_child)
qdisc_put(old_child);
return 0;
}