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From: Yury Norov <ynorov@nvidia.com>
To: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>, Thomas Gleixner <tglx@kernel.org>,
	Juri Lelli <juri.lelli@redhat.com>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: Yury Norov <ynorov@nvidia.com>, Yury Norov <yury.norov@gmail.com>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Alexander Gordeev <agordeev@linux.ibm.com>,
	Andrea Righi <arighi@nvidia.com>, Ben Segall <bsegall@google.com>,
	Christian Borntraeger <borntraeger@linux.ibm.com>,
	Danilo Krummrich <dakr@kernel.org>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Heiko Carstens <hca@linux.ibm.com>,
	Ilya Leoshkevich <iii@linux.ibm.com>,
	Johan Hovold <johan@kernel.org>, Jonathan Corbet <corbet@lwn.net>,
	K Prateek Nayak <kprateek.nayak@amd.com>,
	Maxim Kuvyrkov <maxim.kuvyrkov@grdncc.com>,
	Mel Gorman <mgorman@suse.de>, Mete Durlu <meted@linux.ibm.com>,
	Randy Dunlap <rdunlap@infradead.org>,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>,
	Shuah Khan <skhan@linuxfoundation.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Sven Schnelle <svens@linux.ibm.com>,
	Valentin Schneider <vschneid@redhat.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
	driver-core@lists.linux.dev, linux-s390@vger.kernel.org
Subject: [PATCH 3/7] virt: steal_governor: remove the minimum elapsed-time check
Date: Fri, 13 Nov 2026 13:42:52 -0500	[thread overview]
Message-ID: <20261113184257.621707-4-ynorov@nvidia.com> (raw)
In-Reply-To: <20261113184257.621707-1-ynorov@nvidia.com>

The governor queues its worker with a sampling interval of at least
100ms, so its one-millisecond elapsed-time check is redundant. The
existing denominator clamp already prevents division by zero when
calculating the steal ratio.

This series adds a hook on hotplug events. It may trigger this error
path pointlessly. Just drop it.

Signed-off-by: Yury Norov <ynorov@nvidia.com>
---
 drivers/virt/steal_governor.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/virt/steal_governor.c b/drivers/virt/steal_governor.c
index 99bebd3dee8c..26b6bcca27ed 100644
--- a/drivers/virt/steal_governor.c
+++ b/drivers/virt/steal_governor.c
@@ -216,11 +216,6 @@ static void steal_governor_loop(struct work_struct *work)
 	now = ktime_get();
 	delta_ns = ktime_to_ns(ktime_sub(now, sg_ctx.time));
 
-	if (unlikely(delta_ns < NSEC_PER_MSEC)) {
-		pr_err_ratelimited("work scheduled too soon delta_ns: %llu\n", delta_ns);
-		goto requeue_work;
-	}
-
 	curr_steal = get_system_steal_time();
 	delta_steal = curr_steal > sg_ctx.steal ? curr_steal - sg_ctx.steal : 0;
 	sg_ctx.steal = curr_steal;
@@ -249,7 +244,6 @@ static void steal_governor_loop(struct work_struct *work)
 		return;
 	}
 
-requeue_work:
 	schedule_delayed_work(&sg_ctx.work, sg_ctx.delay);
 }
 
-- 
2.53.0


  parent reply	other threads:[~2026-11-13 19:48 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-13 18:42 [PATCH 0/7] Harden preferred CPUs management Yury Norov
2026-11-13 18:42 ` [PATCH 1/7] cpumask: add reset_preferred_cpumask() helper Yury Norov
2026-11-13 18:42 ` [PATCH 2/7] sched: restore preferred CPUs when hotplug removes the last one Yury Norov
2026-11-13 18:42 ` Yury Norov [this message]
2026-11-13 18:42 ` [PATCH 4/7] virt: steal_governor: serialize sampling against CPU hotplug Yury Norov
2026-11-13 18:42 ` [PATCH 5/7] virt: steal_governor: warn on unexpected preferred mask states Yury Norov
2026-11-13 18:42 ` [PATCH 6/7] virt: steal_governor: restart sampling immediately after CPU hotplug Yury Norov
2026-11-13 18:42 ` [PATCH 7/7] cpu: make preferred CPU policy writers mutually exclusive Yury Norov

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