linux-kernel - [tip: sched/core] sched/psi: Delete the 'update_total' function parameter from update

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Message-ID: <169705924586.3135.13461721051414681406.tip-bot2@tip-bot2>
Date:   Wed, 11 Oct 2023 21:20:45 -0000
From:   "tip-bot2 for Yang Yang" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Yang Yang <yang.yang29@....com.cn>, Ingo Molnar <mingo@...nel.org>,
        Johannes Weiner <hannes@...xchg.org>,
        Suren Baghdasaryan <surenb@...gle.com>,
        Peter Ziljstra <peterz@...radead.org>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: sched/core] sched/psi: Delete the 'update_total' function
 parameter from update_triggers()

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     3657680f38cd7df413d665f2b2f38e9a78130d8b
Gitweb:        https://git.kernel.org/tip/3657680f38cd7df413d665f2b2f38e9a78130d8b
Author:        Yang Yang <yang.yang29@....com.cn>
AuthorDate:    Tue, 10 Oct 2023 16:45:43 +08:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Wed, 11 Oct 2023 23:08:09 +02:00

sched/psi: Delete the 'update_total' function parameter from update_triggers()

The 'update_total' parameter of update_triggers() is always true after the
previous commit:

  80cc1d1d5ee3 ("sched/psi: Avoid updating PSI triggers and ->rtpoll_total when there are no state changes")

If the 'changed_states & group->rtpoll_states' condition is true,
'new_stall' in update_triggers() will be true, and then 'update_total'
should also be true.

So update_total is redundant - remove it.

[ mingo: Changelog updates ]

Signed-off-by: Yang Yang <yang.yang29@....com.cn>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Cc: Johannes Weiner <hannes@...xchg.org>
Cc: Suren Baghdasaryan <surenb@...gle.com>
Cc: Peter Ziljstra <peterz@...radead.org>
Link: https://lore.kernel.org/r/202310101645437859599@zte.com.cn
---
 kernel/sched/psi.c | 17 +++--------------
 1 file changed, 3 insertions(+), 14 deletions(-)

diff --git a/kernel/sched/psi.c b/kernel/sched/psi.c
index 79f8db0..44a7877 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 void 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 void 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) {
@@ -563,7 +554,6 @@ 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);
@@ -582,7 +572,7 @@ 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);
 	}
 
@@ -638,7 +628,6 @@ 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);
@@ -705,7 +694,7 @@ static void psi_rtpoll_work(struct psi_group *group)
 
 	if (now >= group->rtpoll_next_update) {
 		if (changed_states & group->rtpoll_states) {
-			update_triggers(group, now, &update_total, PSI_POLL);
+			update_triggers(group, now, PSI_POLL);
 			memcpy(group->rtpoll_total, group->total[PSI_POLL],
 				   sizeof(group->rtpoll_total));
 		}