Re: [PATCH net v2 2/2] net/sched: taprio: do not replay missed entries in advance_sched()

[Krystian Kaniewski]

On 10/14/26 22:51, Vinicius Costa Gomes wrote:
>>>> +	struct sched_entry *entry, *found = NULL;
>>>> +	ktime_t cycle_start = sched->start_time;
>>>> +	s64 offset, entry_end = 0, elapsed = 0;
>>>> +
>>>> +	if (ktime_after(now, cycle_start)) {
>>>> +		s64 periods = div64_s64(ktime_sub(now, cycle_start),
>>>> +					sched->period);
>>>> +
>>>> +		cycle_start = ktime_add_ns(cycle_start,
>>>> +					   periods * sched->period);
>>>> +	}
>>>> +	offset = ktime_sub(now, cycle_start);
>>>> +
>>>> +	/* The offset is less than one period, so an entry which ends after
>>>> +	 * @now is found at the latest at the entry which reaches the end of
>>>> +	 * the cycle, or at the last entry. A schedule has at least one entry,
>>>> +	 * so the loop always sets found.
>>>> +	 */
>>>> +	list_for_each_entry(entry, &sched->entries, list) {
>>>> +		entry_end = min_t(s64, elapsed + entry->interval,
>>>> +				  sched->cycle_time);
>>>> +		if (offset < entry_end ||
>>>> +		    list_is_last(&entry->list, &sched->entries)) {
>>>> +			found = entry;
>>>> +			break;
>>>> +		}
>>>> +		elapsed = entry_end;
>>>> +	}
>>>> +
>>>> +	*start = ktime_add_ns(cycle_start, elapsed);
>>>> +	*end = ktime_add_ns(cycle_start, entry_end);
>>>> +	sched->cycle_end_time = ktime_add_ns(cycle_start,
>>>> sched->cycle_time);
>>>
>>> Having this side effect here was unexpected. I think this would make
>>> more sense outside this function.
>>>
>>
>> Agreed. I can make taprio_entry_at() return the cycle end through an
>> extra output argument and have advance_sched() store it explicitly in
>> oper->cycle_end_time. The helper could then take the schedule as const.
>>
>> I can wait for the rest of your review of this patch before sending v3
>>
> 
> I am going to try and review this by end of this week.
> 
> 
> Cheers,

Hi Vinicius,

Just a gentle ping on patch 2/2. Did you have a chance to continue the
review?
-- 
Krystian Kaniewski