Messages in this thread | | | From | Suren Baghdasaryan <> | Date | Mon, 17 Apr 2023 12:04:08 -0700 | Subject | Re: [PATCH linux-next] sched/psi: avoid unnecessary resetting min update period when destroy trigger |
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On Mon, Apr 17, 2023 at 1:12 AM <yang.yang29@zte.com.cn> wrote: > > From: Yang Yang <yang.yang19@zte.com.cn> > > Psi_group's poll_min_period is determined by the min window size of > psi_trigger when creating new triggers. While destroying a psi_trigger, > there is no need to reset poll_min_period if the destroying psi_trigger > not had the min windows size, since in this condition poll_min_period > will keep the same as before.
Nice optimization.
> > Signed-off-by: Yang Yang <yang.yang29@zte.com.cn>
Acked-by: Suren Baghdasaryan <surenb@google.com>
> --- > kernel/sched/psi.c | 15 ++++++++++----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c > index 02e011cabe91..12869585cf89 100644 > --- a/kernel/sched/psi.c > +++ b/kernel/sched/psi.c > @@ -1359,11 +1359,16 @@ void psi_trigger_destroy(struct psi_trigger *t) > group->nr_triggers[t->state]--; > if (!group->nr_triggers[t->state]) > group->poll_states &= ~(1 << t->state); > - /* reset min update period for the remaining triggers */ > - list_for_each_entry(tmp, &group->triggers, node) > - period = min(period, div_u64(tmp->win.size, > - UPDATES_PER_WINDOW)); > - group->poll_min_period = period; > + /* > + * Reset min update period for the remaining triggers iff the destroying > + * trigger had the min window size. > + */ > + if (group->poll_min_period == div_u64(t->win.size, UPDATES_PER_WINDOW)) { > + list_for_each_entry(tmp, &group->triggers, node) > + period = min(period, div_u64(tmp->win.size, > + UPDATES_PER_WINDOW)); > + group->poll_min_period = period; > + } > /* Destroy poll_task when the last trigger is destroyed */ > if (group->poll_states == 0) { > group->polling_until = 0; > -- > 2.25.1
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