From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 92632335BA1; Mon, 18 Aug 2025 13:27:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755523633; cv=none; b=k1VHjaX/QKEuIFqON09YQ0fVs6hPdGmHBzky5+WmyJPx2fQtbd3tJ1nJEs2vWTYLHyfPw9JnxT1YR1EVCBJY2PbVxlDtBKRY4GjUCZuBMOO0n+SjyPEV/KmeeCONyCeToBZWnjAIRoyBpSfBTv0z0bEF65brF/NZ0oY1Mrabky4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755523633; c=relaxed/simple; bh=4QK+ZDky9iShKO6RUk7kT8b4mTmEA441++/punGYfCk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BgSNpAAQRMNTEvSsJJ04/f0B6XQ06qCxkKm10PSUuaoX9FBRLflGQlP2G03DkdKEvVdUdOw0YvTEbO6HV3D3vq05vdnJ/nd1B/tBQuvnuKpflNTd5cPKHhMDQ5ZLUnW6GLG8N3+G7S/2bcF6ktjlexFtL0ykhDOQCtB748jHf5o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=jXuY0V/X; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="jXuY0V/X" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9B666C113D0; Mon, 18 Aug 2025 13:27:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1755523633; bh=4QK+ZDky9iShKO6RUk7kT8b4mTmEA441++/punGYfCk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jXuY0V/X0ZOZuE2SxEdgi60Ij4H7fV2eEL35n7MAUGbML1OwJGvjMrwfFRrMK20DF I0Cj2V2LiSlcycTuWlBJ7JNr+9pZ7Gsx3V5b7IYhKD1clnDgv5ZbkNUkerDQ/ZTDCA LJZL0Z4b735rFLSGG6kLDPcVbnvePh98PDgm3o7s= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Marcel Ziswiler , Juri Lelli , "Peter Zijlstra (Intel)" , Sasha Levin Subject: [PATCH 6.15 232/515] sched/deadline: Fix accounting after global limits change Date: Mon, 18 Aug 2025 14:43:38 +0200 Message-ID: <20250818124507.306825638@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250818124458.334548733@linuxfoundation.org> References: <20250818124458.334548733@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Juri Lelli [ Upstream commit 440989c10f4e32620e9e2717ca52c3ed7ae11048 ] A global limits change (sched_rt_handler() logic) currently leaves stale and/or incorrect values in variables related to accounting (e.g. extra_bw). Properly clean up per runqueue variables before implementing the change and rebuild scheduling domains (so that accounting is also properly restored) after such a change is complete. Reported-by: Marcel Ziswiler Signed-off-by: Juri Lelli Signed-off-by: Peter Zijlstra (Intel) Tested-by: Marcel Ziswiler # nuc & rock5b Link: https://lore.kernel.org/r/20250627115118.438797-4-juri.lelli@redhat.com Signed-off-by: Sasha Levin --- kernel/sched/deadline.c | 4 +++- kernel/sched/rt.c | 6 ++++++ 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index 65f3b2cc891d..d86b211f2c14 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -3249,6 +3249,9 @@ void sched_dl_do_global(void) if (global_rt_runtime() != RUNTIME_INF) new_bw = to_ratio(global_rt_period(), global_rt_runtime()); + for_each_possible_cpu(cpu) + init_dl_rq_bw_ratio(&cpu_rq(cpu)->dl); + for_each_possible_cpu(cpu) { rcu_read_lock_sched(); @@ -3264,7 +3267,6 @@ void sched_dl_do_global(void) raw_spin_unlock_irqrestore(&dl_b->lock, flags); rcu_read_unlock_sched(); - init_dl_rq_bw_ratio(&cpu_rq(cpu)->dl); } } diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index bfcb8b0a1e2c..41a216fec3ce 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -2936,6 +2936,12 @@ static int sched_rt_handler(const struct ctl_table *table, int write, void *buff sched_domains_mutex_unlock(); mutex_unlock(&mutex); + /* + * After changing maximum available bandwidth for DEADLINE, we need to + * recompute per root domain and per cpus variables accordingly. + */ + rebuild_sched_domains(); + return ret; } -- 2.39.5