Messages in this thread Patch in this message | | | From | Faizal Rahim <> | Subject | [PATCH v2 net 5/7] net/sched: taprio: fix delayed switching to new schedule after timer expiry | Date | Tue, 7 Nov 2023 06:20:21 -0500 |
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If a new GCL is triggered and the new admin base time falls before the expiry of advance_timer (current running entry from oper), taprio_start_sched() resets the current advance_timer expiry to the new admin base time. However, upon expiry, advance_sched() doesn't immediately switch to the admin schedule. It continues running entries from the old oper schedule, and only switches to the new admin schedule much later. Ideally, if the advance_timer is shorten to align with the new admin base time, when the timer expires, advance_sched() should trigger switch_schedules() at the beginning.
To resolve this issue, set the cycle_time_correction to a non-initialized value in taprio_start_sched(). advance_sched() will use it to initiate switch_schedules() at the beginning.
Fixes: a3d43c0d56f1 ("taprio: Add support adding an admin schedule") Signed-off-by: Faizal Rahim <faizal.abdul.rahim@linux.intel.com> --- net/sched/sch_taprio.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-)
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index f18a5fe12f0c..01b114edec30 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -1379,14 +1379,19 @@ static void setup_first_end_time(struct taprio_sched *q, } static void taprio_start_sched(struct Qdisc *sch, - ktime_t start, struct sched_gate_list *new) + ktime_t new_base_time, + struct sched_gate_list *new) { struct taprio_sched *q = qdisc_priv(sch); - ktime_t expires; + struct sched_gate_list *oper = NULL; + ktime_t expires, start; if (FULL_OFFLOAD_IS_ENABLED(q->flags)) return; + oper = rcu_dereference_protected(q->oper_sched, + lockdep_is_held(&q->current_entry_lock)); + expires = hrtimer_get_expires(&q->advance_timer); if (expires == 0) expires = KTIME_MAX; @@ -1395,7 +1400,17 @@ static void taprio_start_sched(struct Qdisc *sch, * reprogram it to the earliest one, so we change the admin * schedule to the operational one at the right time. */ - start = min_t(ktime_t, start, expires); + start = min_t(ktime_t, new_base_time, expires); + + if (expires != KTIME_MAX && + ktime_compare(start, new_base_time) == 0) { + /* Since timer was changed to align to the new admin schedule, + * setting the variable below to a non-initialized value will + * indicate to advance_sched() to call switch_schedules() after + * this timer expires. + */ + oper->cycle_time_correction = 0; + } hrtimer_start(&q->advance_timer, start, HRTIMER_MODE_ABS); } -- 2.25.1
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