From: Suren Baghdasaryan <surenb@google.com>
To: yang.yang29@zte.com.cn
Cc: hannes@cmpxchg.org, mingo@redhat.com,
linux-kernel@vger.kernel.org, juri.lelli@redhat.com,
Suren Baghdasaryan <surenb@google.com>
Subject: Re: [PATCH linux-next] sched/psi: Avoid update triggers and rtpoll_total when it is unnecessary
Date: Tue, 26 Sep 2023 17:14:16 -0700 [thread overview]
Message-ID: <CAJuCfpG2aEv50KFWu4m8isg9dDWQxY9uCGhm=Y0N0AaqPHir8Q@mail.gmail.com> (raw)
In-Reply-To: <202309141710195376952@zte.com.cn>
On Thu, Sep 14, 2023 at 2:10 AM <yang.yang29@zte.com.cn> wrote:
>
> Update_total in update_triggers() is also only used by psi_rtpoll_work().
> And when changed_states & group->rtpoll_states is true, update_total
> should also be true, so try to delete update_total, please see below:
Sorry, I know I owe a review here. I'll try to review it by the end of
this week.
Suren.
>
> ---
> kernel/sched/psi.c | 24 +++++++-----------------
> 1 file changed, 7 insertions(+), 17 deletions(-)
>
> diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
> index 81fca77397f6..744ba8b4e029 100644
> --- a/kernel/sched/psi.c
> +++ b/kernel/sched/psi.c
> @@ -434,14 +434,13 @@ static u64 window_update(struct psi_window *win, u64 now, u64 value)
> return growth;
> }
>
> -static u64 update_triggers(struct psi_group *group, u64 now, bool *update_total,
> +static void update_triggers(struct psi_group *group, u64 now,
> enum psi_aggregators aggregator)
> {
> struct psi_trigger *t;
> u64 *total = group->total[aggregator];
> struct list_head *triggers;
> u64 *aggregator_total;
> - *update_total = false;
>
> if (aggregator == PSI_AVGS) {
> triggers = &group->avg_triggers;
> @@ -471,14 +470,6 @@ static u64 update_triggers(struct psi_group *group, u64 now, bool *update_total,
> * events without dropping any).
> */
> if (new_stall) {
> - /*
> - * Multiple triggers might be looking at the same state,
> - * remember to update group->polling_total[] once we've
> - * been through all of them. Also remember to extend the
> - * polling time if we see new stall activity.
> - */
> - *update_total = true;
> -
> /* Calculate growth since last update */
> growth = window_update(&t->win, now, total[t->state]);
> if (!t->pending_event) {
> @@ -499,8 +490,6 @@ static u64 update_triggers(struct psi_group *group, u64 now, bool *update_total,
> /* Reset threshold breach flag once event got generated */
> t->pending_event = false;
> }
> -
> - return now + group->rtpoll_min_period;
> }
>
> static u64 update_averages(struct psi_group *group, u64 now)
> @@ -561,7 +550,6 @@ static void psi_avgs_work(struct work_struct *work)
> struct delayed_work *dwork;
> struct psi_group *group;
> u32 changed_states;
> - bool update_total;
> u64 now;
>
> dwork = to_delayed_work(work);
> @@ -580,7 +568,7 @@ static void psi_avgs_work(struct work_struct *work)
> * go - see calc_avgs() and missed_periods.
> */
> if (now >= group->avg_next_update) {
> - update_triggers(group, now, &update_total, PSI_AVGS);
> + update_triggers(group, now, PSI_AVGS);
> group->avg_next_update = update_averages(group, now);
> }
>
> @@ -636,7 +624,6 @@ static void psi_rtpoll_work(struct psi_group *group)
> {
> bool force_reschedule = false;
> u32 changed_states;
> - bool update_total;
> u64 now;
>
> mutex_lock(&group->rtpoll_trigger_lock);
> @@ -702,10 +689,13 @@ static void psi_rtpoll_work(struct psi_group *group)
> }
>
> if (now >= group->rtpoll_next_update) {
> - group->rtpoll_next_update = update_triggers(group, now, &update_total, PSI_POLL);
> - if (update_total)
> + group->rtpoll_next_update = now + group->rtpoll_min_period;
> +
> + if (changed_states & group->rtpoll_states) {
> + update_triggers(group, now, PSI_POLL);
> memcpy(group->rtpoll_total, group->total[PSI_POLL],
> sizeof(group->rtpoll_total));
> + }
> }
>
> psi_schedule_rtpoll_work(group,
> --
> 2.25.1
next prev parent reply other threads:[~2023-09-27 0:58 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-13 12:44 [PATCH linux-next] sched/psi: Avoid update triggers and rtpoll_total when it is unnecessary yang.yang29
2023-09-13 23:01 ` Suren Baghdasaryan
2023-09-14 2:02 ` yang.yang29
2023-09-14 5:53 ` yang.yang29
2023-09-14 9:10 ` yang.yang29
2023-09-27 0:14 ` Suren Baghdasaryan [this message]
2023-09-27 1:56 ` yang.yang29
2023-09-30 22:32 ` Suren Baghdasaryan
2023-10-07 6:21 ` [PATCH linux-next v2] " yang.yang29
2023-10-09 10:49 ` Ingo Molnar
2023-10-09 12:19 ` [PATCH linux-next 0/3] sched/psi: Optimize the process of updating triggers and rtpoll_total yang.yang29
2023-10-09 12:24 ` [PATCH linux-next 1/3] sched/psi: Change update_triggers() to a void function yang.yang29
2023-10-09 12:48 ` Ingo Molnar
2023-10-09 12:59 ` [tip: sched/core] sched/psi: Change update_triggers() to a 'void' function tip-bot2 for Yang Yang
2023-10-09 12:30 ` [PATCH linux-next 2/3] sched/psi: Avoid update triggers and rtpoll_total when it is unnecessary yang.yang29
2023-10-09 12:52 ` Ingo Molnar
2023-10-09 17:42 ` Suren Baghdasaryan
2023-10-10 2:12 ` yang.yang29
2023-10-10 3:05 ` [PATCH linux-next v2 0/4] sched/psi: Optimize the process of updating triggers and rtpoll_total yang.yang29
2023-10-10 3:09 ` [PATCH linux-next v2 1/4] sched/psi: Change update_triggers() to a 'void' function yang.yang29
2023-10-10 7:38 ` Ingo Molnar
2023-10-10 8:31 ` [PATCH linux-next v3 0/4] sched/psi: Optimize the process of updating triggers and rtpoll_total yang.yang29
2023-10-10 8:36 ` [PATCH linux-next v3 1/4] sched/psi: Change update_triggers() to a 'void' function yang.yang29
2023-10-19 16:01 ` Suren Baghdasaryan
2023-10-10 8:41 ` [PATCH linux-next v3 2/4] sched/psi: Avoid update triggers and rtpoll_total when it is unnecessary yang.yang29
2023-10-11 21:15 ` Ingo Molnar
2023-10-12 2:13 ` yang.yang29
2023-10-19 16:04 ` Suren Baghdasaryan
2023-10-11 21:20 ` [tip: sched/core] sched/psi: Avoid updating PSI triggers and ->rtpoll_total when there are no state changes tip-bot2 for Yang Yang
2023-10-10 8:42 ` [PATCH linux-next v3 3/4] sched/psi: update rtpoll_next_update after update triggers and rtpoll_total yang.yang29
2023-10-19 16:07 ` Suren Baghdasaryan
2023-10-10 8:45 ` [PATCH linux-next v3 4/4] sched/psi: Delete the function parameter update_total of update_triggers() yang.yang29
2023-10-11 21:20 ` [tip: sched/core] sched/psi: Delete the 'update_total' function parameter from update_triggers() tip-bot2 for Yang Yang
2023-10-19 16:09 ` [PATCH linux-next v3 4/4] sched/psi: Delete the function parameter update_total of update_triggers() Suren Baghdasaryan
2023-10-10 3:20 ` [PATCH linux-next v2 2/4] sched/psi: Avoid update triggers and rtpoll_total when it is unnecessary yang.yang29
2023-10-10 3:24 ` [PATCH linux-next v2 3/4] sched/psi: update rtpoll_next_update after update triggers and rtpoll_total yang.yang29
2023-10-10 3:28 ` [PATCH linux-next v2 4/4] sched/psi: Delete the function parameter update_total of update_triggers() yang.yang29
2023-10-09 12:37 ` [PATCH linux-next 3/3] " yang.yang29
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