On 29/03/2023 16:31, Waiman Long wrote:
> On 3/29/23 10:25, Waiman Long wrote:
>>
>> On 3/29/23 08:55, Juri Lelli wrote:
>>> From: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
[...]
>>> @@ -2518,11 +2547,21 @@ static int cpuset_can_attach(struct
>>> cgroup_taskset *tset)
>>> static void cpuset_cancel_attach(struct cgroup_taskset *tset)
>>> {
>>> struct cgroup_subsys_state *css;
>>> + struct cpuset *cs;
>>> cgroup_taskset_first(tset, &css);
>>> + cs = css_cs(css);
>>> mutex_lock(&cpuset_mutex);
>>> - css_cs(css)->attach_in_progress--;
>>> + cs->attach_in_progress--;
>>> +
>>> + if (cs->nr_migrate_dl_tasks) {
>>> + int cpu = cpumask_any(cs->effective_cpus);
>>> +
>>> + dl_bw_free(cpu, cs->sum_migrate_dl_bw);
>>> + reset_migrate_dl_data(cs);
>>> + }
>>> +
>
> Another nit that I have is that you may have to record also the cpu
> where the DL bandwidth is allocated in cpuset_can_attach() and free the
> bandwidth back into that cpu or there can be an underflow if another cpu
> is chosen.
Many thanks for the review!
But isn't the DL BW control `struct dl_bw` per `struct root_domain`
which is per exclusive cpuset. So as long cpu is from
`cs->effective_cpus` shouldn't this be fine?
