From b88948fbc7cec03bd97fe5be65264681e98041e8 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 16 Mar 2020 19:12:50 -0700 Subject: net_sched: do not reprogram a timer about to expire qdisc_watchdog_schedule_range_ns() can use the newly added slack and avoid rearming the hrtimer a bit earlier than the current value. This patch has no effect if delta_ns parameter is zero. Note that this means the max slack is potentially doubled. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/sched/sch_api.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'net/sched/sch_api.c') diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c index 83984be04f57..0d99df1e764d 100644 --- a/net/sched/sch_api.c +++ b/net/sched/sch_api.c @@ -625,8 +625,13 @@ void qdisc_watchdog_schedule_range_ns(struct qdisc_watchdog *wd, u64 expires, &qdisc_root_sleeping(wd->qdisc)->state)) return; - if (wd->last_expires == expires) - return; + if (hrtimer_is_queued(&wd->timer)) { + /* If timer is already set in [expires, expires + delta_ns], + * do not reprogram it. + */ + if (wd->last_expires - expires <= delta_ns) + return; + } wd->last_expires = expires; hrtimer_start_range_ns(&wd->timer, -- cgit