From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 BCAAD263F34 for ; Thu, 14 May 2026 04:26:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778732808; cv=none; b=imbyLgpnaF92k8kYheZHp2hq5Kwe+faoAOba+bNUvxb+Ayt3LCkEz35y60bVgtC6HlSVTqPzjPCdiwSP+AwFqJf7jyGpv4F8+N6+Rl0Zeb7B601SDACL/Y4Vue/h/LyPskTRAepgbaTGkyYUJzn/5qibucNQeuIWlA6l5bEY7nw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778732808; c=relaxed/simple; bh=H+QTUiaHx8+v++cYc5L7w1Z6hyfvNCmGKDJXCtgS/l0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=bfD4mwFpK22fyjhJnaxbbn3ha5Xe+iWohdsMfJQxn7yjOkmELdtumClViJKbhAML3C96EMrcIj6WaaBESJ8YoqkLDUxyPp0Kp1bhp0mGfSCcmg54DMQ9tRjvfNWyPwGxyDj4IY6ngNr80k0GmfbedtmF7tcNSBdcmwSiTL0ikXs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=a8fOUTSe; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="a8fOUTSe" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1778732805; h=from:from: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=rsS1TwMGUD2Gx+sJxdKIX/0hmaBzXUjdGlntTlTmgZ8=; b=a8fOUTSehVHXVkTQ7qWf+fLEVYQUhnfiXy6ctMujxBc2Hb9mT7sPZDzfnuEQKqZx9Yiegy PBpAOz3Jzai0nSzhMl3uDh7CA+1ub2rwPMTwV9HQJbM/KBQQgbr27CMxvEdK0RftHh5FeP EIrPOCxIY4jk03w1lD1nBN5nRNdvBwM= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-680-t0OQj1KpM8yQy6SBBPOmDw-1; Thu, 14 May 2026 00:26:42 -0400 X-MC-Unique: t0OQj1KpM8yQy6SBBPOmDw-1 X-Mimecast-MFC-AGG-ID: t0OQj1KpM8yQy6SBBPOmDw_1778732800 Received: from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id F0F85195609E; Thu, 14 May 2026 04:26:39 +0000 (UTC) Received: from [10.2.16.30] (unknown [10.2.16.30]) by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 405061800347; Thu, 14 May 2026 04:26:36 +0000 (UTC) Message-ID: Date: Thu, 14 May 2026 00:26:35 -0400 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] cpuset: Fix multi-source deadline task accounting and bandwidth bypass To: Aaron Tomlin Cc: Dietmar Eggemann , tj@kernel.org, hannes@cmpxchg.org, mkoutny@suse.com, chenridong@huaweicloud.com, neelx@suse.com, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260512010341.101419-1-atomlin@atomlin.com> <7ae7fe29-6405-41e3-9f3b-6c1d0255dc9e@redhat.com> Content-Language: en-US From: Waiman Long In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.93 On 5/13/26 7:39 PM, Aaron Tomlin wrote: > On Wed, May 13, 2026 at 07:19:18PM -0400, Waiman Long wrote: >> Multiple source or destination cpusets in task migration can only happens >> when the cpuset controller is enabled or disabled in a cgroup subtree. If >> there are DL tasks in 2 or more child cgroups, enabling or disabling of the >> cpuset controller for those child cgroups may lead to incorrect DL task >> accounting. This patch will probably fix the DL accounting aspect. However, >> there are also other issues unrelated to DL tasks that need to be addressed >> as well. So this patch is incomplete in this regard. I am working on a patch >> series to address these issues. Hopefully I can send it out in a day or 2. >> > Hi Longman, > > Acknowledged. > > Also, the Sashiko AI review reported: "TOCTOU race on dl_task(task) during > rollback causes state corruption." > > A concurrent sched_setscheduler() could alter the scheduling class of a > task between the initial pass and a rollback. This assertion seems valid to > me. Currently, neither cgroup_mutex or cpuset_mutex prevents scheduling > class changes. > > Should I let you handle this too? No, you can handle it if you want. I am more familiar with the cpuset code, but scheduler is much more complex. I don't think I have enough understanding of the code to handle it correctly. Cheers, Longman