From: Ajay Kaher <ajay.kaher@broadcom.com>
To: stable@vger.kernel.org, gregkh@linuxfoundation.org
Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
vschneid@redhat.com, linux-kernel@vger.kernel.org,
ajay.kaher@broadcom.com, alexey.makhalov@broadcom.com,
yin.ding@broadcom.com, tapas.kundu@broadcom.com,
Chris Mason <clm@meta.com>
Subject: [PATCH v6.1 3/4] sched/fair: Small cleanup to update_newidle_cost()
Date: Wed, 3 Dec 2025 11:25:51 +0000 [thread overview]
Message-ID: <20251203112552.1738424-4-ajay.kaher@broadcom.com> (raw)
In-Reply-To: <20251203112552.1738424-1-ajay.kaher@broadcom.com>
From: Peter Zijlstra <peterz@infradead.org>
commit 08d473dd8718e4a4d698b1113a14a40ad64a909b upstream.
Simplify code by adding a few variables.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Chris Mason <clm@meta.com>
Link: https://patch.msgid.link/20251107161739.655208666@infradead.org
[ Ajay: Modified to apply on v6.1 ]
Signed-off-by: Ajay Kaher <ajay.kaher@broadcom.com>
---
kernel/sched/fair.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 9a7aa83ca..2f296e2af 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -10937,22 +10937,25 @@ void update_max_interval(void)
static inline bool update_newidle_cost(struct sched_domain *sd, u64 cost)
{
+ unsigned long next_decay = sd->last_decay_max_lb_cost + HZ;
+ unsigned long now = jiffies;
+
if (cost > sd->max_newidle_lb_cost) {
/*
* Track max cost of a domain to make sure to not delay the
* next wakeup on the CPU.
*/
sd->max_newidle_lb_cost = cost;
- sd->last_decay_max_lb_cost = jiffies;
- } else if (time_after(jiffies, sd->last_decay_max_lb_cost + HZ)) {
+ sd->last_decay_max_lb_cost = now;
+
+ } else if (time_after(now, next_decay)) {
/*
* Decay the newidle max times by ~1% per second to ensure that
* it is not outdated and the current max cost is actually
* shorter.
*/
sd->max_newidle_lb_cost = (sd->max_newidle_lb_cost * 253) / 256;
- sd->last_decay_max_lb_cost = jiffies;
-
+ sd->last_decay_max_lb_cost = now;
return true;
}
--
2.40.4
next prev parent reply other threads:[~2025-12-03 11:43 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-03 11:25 [PATCH v6.1 0/4] sched: The newidle balance regression Ajay Kaher
2025-12-03 11:25 ` [PATCH v6.1 1/4] sched/fair: Revert max_newidle_lb_cost bump Ajay Kaher
2025-12-03 11:25 ` [PATCH v6.1 2/4] sched/fair: Small cleanup to sched_balance_newidle() Ajay Kaher
2025-12-03 11:25 ` Ajay Kaher [this message]
2025-12-03 11:25 ` [PATCH v6.1 4/4] sched/fair: Proportional newidle balance Ajay Kaher
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20251203112552.1738424-4-ajay.kaher@broadcom.com \
--to=ajay.kaher@broadcom.com \
--cc=alexey.makhalov@broadcom.com \
--cc=bsegall@google.com \
--cc=clm@meta.com \
--cc=dietmar.eggemann@arm.com \
--cc=gregkh@linuxfoundation.org \
--cc=juri.lelli@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mgorman@suse.de \
--cc=mingo@redhat.com \
--cc=peterz@infradead.org \
--cc=rostedt@goodmis.org \
--cc=stable@vger.kernel.org \
--cc=tapas.kundu@broadcom.com \
--cc=vincent.guittot@linaro.org \
--cc=vschneid@redhat.com \
--cc=yin.ding@broadcom.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox