From nobody Fri Oct 3 18:10:04 2025 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CF65B3148C8; Wed, 27 Aug 2025 06:45:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756277140; cv=none; b=M48hVh6SMg97mvpeg9sEKyR/mK5dOKSY8qHQl4x/4HjL2jLk9fWFv38ftgDlWqzNA3AG/abR7Flbgib0nZLmyEmU28oacL5EMS2e1Y/JcIhlTaAIc7XzLjI27LbWQaOlO1qQ3SMqDmzdTZuOQR6BmHjLaRRHRjGkqXo2QKQ8vJU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756277140; c=relaxed/simple; bh=qdUPsCe2c5V6aLdoDVO0WUgeE0UEJoBgUxftB60xTTo=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=Anf1piu//5gsT9HqWR2VkNH5T4Rezs/WqLfj+V+qSWXj6nD7bRKA44SKgqLezc7eIN2qNxbuLPPQD6ADL7pG2MSfzWHTeGJRBv/1xq3sHpyxr0nHnJm+K9KENst9gYkpVHliVcf/gxCuntrU6qj8FdI+DbbMZkeDFkA2fbhmezg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=er8ZAXK3; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=rnmED8lz; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="er8ZAXK3"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="rnmED8lz" Date: Wed, 27 Aug 2025 06:45:35 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1756277137; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=D1+QhUSutOTnCFdNgJIy1ND+xr1gyO4p/+sVSr7ghcc=; b=er8ZAXK3Gi5AF+05m22t8S/iaVGKccoq73c4yRvm1vufUQdc8TU2ZDq5NMwFtLUgwDN/2w Up+nwz2prUr1qSxAhpaJe5xAq/+ktn3BIaL610VnDqolUPy+z/tY5Mp8AlDfGiOPfa6Cpo VlzIu/Gcp449yXTbpOzoqAk+KMmGRyb29AFHpU3r++JMZxC8fMaX3wDb4vUhDrCoKGep4O T8VENsMAqVSxbp+ToZwvLNoZ9l/Kub+FLxqSG0pkLadgC+5vuko180VO1fGfQ0eO+csQHL uT7tZe6fDDEbrs76S59DPeh7lnNA2EIN2O+mod96zw29gZHXmS8iNqjKKX69Sg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1756277137; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=D1+QhUSutOTnCFdNgJIy1ND+xr1gyO4p/+sVSr7ghcc=; b=rnmED8lzaepFxkU7jOh0S2Q8/ag0TEWMmJgF2HC9xfPbbcEzqMelFgaFzcqcxG+liq0qor cFilAhIidGK1ufDw== From: "tip-bot2 for Juri Lelli" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: sched/urgent] sched/deadline: Always stop dl-server before changing parameters Cc: Yuri Andriaccio , Juri Lelli , "Peter Zijlstra (Intel)" , Valentin Schneider , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: =?utf-8?q?=3C20250721-upstream-fix-dlserver-lessaggressive-b4-v?= =?utf-8?q?1-1-4ebc10c87e40=40redhat=2Ecom=3E?= References: =?utf-8?q?=3C20250721-upstream-fix-dlserver-lessaggressive-b4-v1?= =?utf-8?q?-1-4ebc10c87e40=40redhat=2Ecom=3E?= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <175627713512.1920.8854712203683421367.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the sched/urgent branch of tip: Commit-ID: bb4700adc3abec34c0a38b64f66258e4e233fc16 Gitweb: https://git.kernel.org/tip/bb4700adc3abec34c0a38b64f66258e4e= 233fc16 Author: Juri Lelli AuthorDate: Mon, 21 Jul 2025 15:01:42 +02:00 Committer: Peter Zijlstra CommitterDate: Tue, 26 Aug 2025 10:46:00 +02:00 sched/deadline: Always stop dl-server before changing parameters Commit cccb45d7c4295 ("sched/deadline: Less agressive dl_server handling") reduced dl-server overhead by delaying disabling servers only after there are no fair task around for a whole period, which means that deadline entities are not dequeued right away on a server stop event. However, the delay opens up a window in which a request for changing server parameters can break per-runqueue running_bw tracking, as reported by Yuri. Close the problematic window by unconditionally calling dl_server_stop() before applying the new parameters (ensuring deadline entities go through an actual dequeue). Fixes: cccb45d7c4295 ("sched/deadline: Less agressive dl_server handling") Reported-by: Yuri Andriaccio Signed-off-by: Juri Lelli Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Valentin Schneider Link: https://lore.kernel.org/r/20250721-upstream-fix-dlserver-lessaggressi= ve-b4-v1-1-4ebc10c87e40@redhat.com --- kernel/sched/debug.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index 3f06ab8..02e16b7 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -376,10 +376,8 @@ static ssize_t sched_fair_server_write(struct file *fi= lp, const char __user *ubu return -EINVAL; } =20 - if (rq->cfs.h_nr_queued) { - update_rq_clock(rq); - dl_server_stop(&rq->fair_server); - } + update_rq_clock(rq); + dl_server_stop(&rq->fair_server); =20 retval =3D dl_server_apply_params(&rq->fair_server, runtime, period, 0); if (retval)