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 F0CF5285043; Tue, 12 Aug 2025 19:10:33 +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=1755025834; cv=none; b=Ygcdmf9g+HbuA+AI754+xSvuhzYtR2/EgI62vBFG1PGqI51PwOITCBJrYL/kVF6LxyleAU5Fm0doQmna+KkCBooYmSRdE8ywntYueRbRQ3j2GR5OSwkKAsSBTh/Kw3gyGdon1ltNhy3VD4qz2N03HLv/bnyzJFCawh4C1OAljH0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755025834; c=relaxed/simple; bh=mjYvJafi0/Bd/k3e1dEYLV2nguBfvKlEQuDPwJU6waA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=E9pdcy5/v1EdOZRcPwGRbZdPq8JbuHVYBZZYBsZ7WLogjKXyS787LSebiDQ4kIPHy+Dd3Bd+kRDpK0AiJr+shX9v+DyylS8oWgkt6V/1dVhY0que/byaw2qGqQnUFkJhI7SJoTGJVZsRt2qsXqv5Dr+gd8Od/FJXt0U9QDc8Gms= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=RRpL4olb; 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="RRpL4olb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D272C4CEF0; Tue, 12 Aug 2025 19:10:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1755025833; bh=mjYvJafi0/Bd/k3e1dEYLV2nguBfvKlEQuDPwJU6waA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RRpL4olbN+srdadtVNWw+I1m/s+9lbAfbajQrthsLcqRpVKoo8dHbQzb+CRQivnAS y4qll947hJIUVxn4Qp53Gcpqp+1Lv1vkpjFbqFT9XkJnhrUrDfNgcgSLyIfQya/ijM Bv+wWwSJBAOIc/INNKF8nTZiphOFENhz96JuOE1c= 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 6.15 158/480] sched/deadline: Reset extra_bw to max_bw when clearing root domains Date: Tue, 12 Aug 2025 19:46:06 +0200 Message-ID: <20250812174404.037999753@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250812174357.281828096@linuxfoundation.org> References: <20250812174357.281828096@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org 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 fcc9276c4d331cd1fe9319d793e80b02e09727f5 ] dl_clear_root_domain() doesn't take into account the fact that per-rq extra_bw variables retain values computed before root domain changes, resulting in broken accounting. Fix it by resetting extra_bw to max_bw before restoring back dl-servers contributions. Fixes: 2ff899e351643 ("sched/deadline: Rebuild root domain accounting after every update") 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/20250627115118.438797-3-juri.lelli@redhat.com Signed-off-by: Sasha Levin --- kernel/sched/deadline.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c index ef5b5c045769..135580a41e14 100644 --- a/kernel/sched/deadline.c +++ b/kernel/sched/deadline.c @@ -3007,7 +3007,14 @@ void dl_clear_root_domain(struct root_domain *rd) int i; guard(raw_spinlock_irqsave)(&rd->dl_bw.lock); + + /* + * Reset total_bw to zero and extra_bw to max_bw so that next + * loop will add dl-servers contributions back properly, + */ rd->dl_bw.total_bw = 0; + for_each_cpu(i, rd->span) + cpu_rq(i)->dl.extra_bw = cpu_rq(i)->dl.max_bw; /* * dl_servers are not tasks. Since dl_add_task_root_domain ignores -- 2.39.5