diff mbox series

[v6,3/4] sched/psi: extract update_triggers side effect

Message ID	20230330105418.77061-4-cerasuolodomenico@gmail.com
State	New
Headers	Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; From: Domenico Cerasuolo <cerasuolodomenico@gmail.com> To: linux-kernel@vger.kernel.org Cc: peterz@infradead.org, surenb@google.com, brauner@kernel.org, chris@chrisdown.name, hannes@cmpxchg.org, Domenico Cerasuolo <cerasuolodomenico@gmail.com> Subject: [PATCH v6 3/4] sched/psi: extract update_triggers side effect Date: Thu, 30 Mar 2023 12:54:17 +0200 Message-Id: <20230330105418.77061-4-cerasuolodomenico@gmail.com> In-Reply-To: <20230330105418.77061-1-cerasuolodomenico@gmail.com> References: <20230330105418.77061-1-cerasuolodomenico@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	sched/psi: Allow unprivileged PSI polling \| [v6,0/4] sched/psi: Allow unprivileged PSI polling [v6,1/4] sched/psi: rearrange polling code in preparation [v6,2/4] sched/psi: rename existing poll members in preparation [v6,3/4] sched/psi: extract update_triggers side effect [v6,4/4] sched/psi: allow unprivileged polling of N*2s period

Commit Message

Domenico Cerasuolo March 30, 2023, 10:54 a.m. UTC

  This change moves update_total flag out of update_triggers function,
currently called only in psi_poll_work.
In the next patch, update_triggers will be called also in psi_avgs_work,
but the total update information is specific to psi_poll_work.
Returning update_total value to the caller let us avoid differentiating
the implementation of update_triggers for different aggregators.

Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
---
 kernel/sched/psi.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

Comments

Suren Baghdasaryan March 30, 2023, 6:41 p.m. UTC | #1

On Thu, Mar 30, 2023 at 3:54 AM Domenico Cerasuolo
<cerasuolodomenico@gmail.com> wrote:
>
> This change moves update_total flag out of update_triggers function,
> currently called only in psi_poll_work.
> In the next patch, update_triggers will be called also in psi_avgs_work,
> but the total update information is specific to psi_poll_work.
> Returning update_total value to the caller let us avoid differentiating
> the implementation of update_triggers for different aggregators.
>
> Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
> Signed-off-by: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
> Acked-by: Johannes Weiner <hannes@cmpxchg.org>

Acked-by: Suren Baghdasaryan <surenb@google.com>

> ---
>  kernel/sched/psi.c | 19 ++++++++++---------
>  1 file changed, 10 insertions(+), 9 deletions(-)
>
> diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
> index a3d0b5cf797a..f3df6a8ff493 100644
> --- a/kernel/sched/psi.c
> +++ b/kernel/sched/psi.c
> @@ -430,11 +430,11 @@ static u64 window_update(struct psi_window *win, u64 now, u64 value)
>         return growth;
>  }
>
> -static u64 update_triggers(struct psi_group *group, u64 now)
> +static u64 update_triggers(struct psi_group *group, u64 now, bool *update_total)
>  {
>         struct psi_trigger *t;
> -       bool update_total = false;
>         u64 *total = group->total[PSI_POLL];
> +       *update_total = false;
>
>         /*
>          * On subsequent updates, calculate growth deltas and let
> @@ -462,7 +462,7 @@ static u64 update_triggers(struct psi_group *group, u64 now)
>                          * been through all of them. Also remember to extend the
>                          * polling time if we see new stall activity.
>                          */
> -                       update_total = true;
> +                       *update_total = true;
>
>                         /* Calculate growth since last update */
>                         growth = window_update(&t->win, now, total[t->state]);
> @@ -485,10 +485,6 @@ static u64 update_triggers(struct psi_group *group, u64 now)
>                 t->pending_event = false;
>         }
>
> -       if (update_total)
> -               memcpy(group->rtpoll_total, total,
> -                               sizeof(group->rtpoll_total));
> -
>         return now + group->rtpoll_min_period;
>  }
>
> @@ -622,6 +618,7 @@ 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);
> @@ -686,8 +683,12 @@ static void psi_rtpoll_work(struct psi_group *group)
>                 goto out;
>         }
>
> -       if (now >= group->rtpoll_next_update)
> -               group->rtpoll_next_update = update_triggers(group, now);
> +       if (now >= group->rtpoll_next_update) {
> +               group->rtpoll_next_update = update_triggers(group, now, &update_total);
> +               if (update_total)
> +                       memcpy(group->rtpoll_total, group->total[PSI_POLL],
> +                                  sizeof(group->rtpoll_total));
> +       }
>
>         psi_schedule_rtpoll_work(group,
>                 nsecs_to_jiffies(group->rtpoll_next_update - now) + 1,
> --
> 2.34.1
>

diff mbox series

Patch

diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index a3d0b5cf797a..f3df6a8ff493 100644
--- a/kernel/sched/psi.c
+++ b/kernel/sched/psi.c
@@ -430,11 +430,11 @@  static u64 window_update(struct psi_window *win, u64 now, u64 value)
 	return growth;
 }
 
-static u64 update_triggers(struct psi_group *group, u64 now)
+static u64 update_triggers(struct psi_group *group, u64 now, bool *update_total)
 {
 	struct psi_trigger *t;
-	bool update_total = false;
 	u64 *total = group->total[PSI_POLL];
+	*update_total = false;
 
 	/*
 	 * On subsequent updates, calculate growth deltas and let
@@ -462,7 +462,7 @@  static u64 update_triggers(struct psi_group *group, u64 now)
 			 * been through all of them. Also remember to extend the
 			 * polling time if we see new stall activity.
 			 */
-			update_total = true;
+			*update_total = true;
 
 			/* Calculate growth since last update */
 			growth = window_update(&t->win, now, total[t->state]);
@@ -485,10 +485,6 @@  static u64 update_triggers(struct psi_group *group, u64 now)
 		t->pending_event = false;
 	}
 
-	if (update_total)
-		memcpy(group->rtpoll_total, total,
-				sizeof(group->rtpoll_total));
-
 	return now + group->rtpoll_min_period;
 }
 
@@ -622,6 +618,7 @@  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);
@@ -686,8 +683,12 @@  static void psi_rtpoll_work(struct psi_group *group)
 		goto out;
 	}
 
-	if (now >= group->rtpoll_next_update)
-		group->rtpoll_next_update = update_triggers(group, now);
+	if (now >= group->rtpoll_next_update) {
+		group->rtpoll_next_update = update_triggers(group, now, &update_total);
+		if (update_total)
+			memcpy(group->rtpoll_total, group->total[PSI_POLL],
+				   sizeof(group->rtpoll_total));
+	}
 
 	psi_schedule_rtpoll_work(group,
 		nsecs_to_jiffies(group->rtpoll_next_update - now) + 1,