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 59144197521; Thu, 14 Nov 2024 18:44:59 +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=1731609900; cv=none; b=q9z/NqfSZxu9S7MrWWEscfJNf6ORWV7Epluao0egUSVae1V1/esJOIKvyjMWr3NivDzxiFNT8KpISpbjLQ5Od9uJlCh6tDKL/z/sLq2XaP2+MuI4bYRvsYt9gJf6Cpmbz5nlenrh3j4blvfbJ1raJZGQ7L1trYduYV1Mtom3Go4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731609900; c=relaxed/simple; bh=5do6qDL9TuXty6Mc70FLBHtfezLZp1QS+cVEkOlzWrM=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=lX05ibj6URFZpc/m84qk5uXeu3XRxpoRhViwGJJqfgfCvSyjgtqylMp0iqV4dWPflmdjhp8c/KBWjp30tSWCKhQl58uDEusXLQoyYZKk6gAvuyq3An2Hj7kkv8q+FkX50MFiUGMF+TuE4ePCrlbzNY9sUbKVJIpC4DwousHHWB8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CQfmrozI; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="CQfmrozI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A41C9C4CECD; Thu, 14 Nov 2024 18:44:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1731609899; bh=5do6qDL9TuXty6Mc70FLBHtfezLZp1QS+cVEkOlzWrM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CQfmrozI7s0BkLt5ojkh/j8dDWsRztEejzf3U89usoQWxYBDaxBYe0ZLwxW/ucXU/ ypCq7PgnQBqxr7g8YQBJKUD6dcwUrvzR96qYhYTImXoNshmpfBw+C+hb00nSYPpDTI +1z0arezEquuMOAHfqtBOSOFB3Wu53tATjf3ul0WrQRoLkYfkkzlhnzCPDBrr8rNB+ W7FkAsnGh5GsKnKd6aOAsI8oT20QfyA33QQRKUMhsMMbC//dlJsgLdwHVAOU2MavrA 1LmNJXhFy+4vbapcI5zbgSuZZX5SjOvwKDZ0ROegLihcItX2JMAZvvfqj7jh1SnszP aaCAiBUigBKyA== Date: Thu, 14 Nov 2024 08:44:58 -1000 From: Tejun Heo To: Waiman Long Cc: Johannes Weiner , Michal =?iso-8859-1?Q?Koutn=FD?= , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Juri Lelli , Phil Auld Subject: Re: [PATCH] cgroup/cpuset: Disable cpuset_cpumask_can_shrink() test if not load balancing Message-ID: References: <20241114181915.142894-1-longman@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241114181915.142894-1-longman@redhat.com> On Thu, Nov 14, 2024 at 01:19:15PM -0500, Waiman Long wrote: > With some recent proposed changes [1] in the deadline server code, > it has caused a test failure in test_cpuset_prs.sh when a change > is being made to an isolated partition. This is due to failing > the cpuset_cpumask_can_shrink() check for SCHED_DEADLINE tasks at > validate_change(). > > This is actually a false positive as the failed test case involves an > isolated partition with load balancing disabled. The deadline check > is not meaningful in this case and the users should know what they > are doing. > > Fix this by doing the cpuset_cpumask_can_shrink() check only when loading > balanced is enabled. Also change its arguments to use effective_cpus > for the current cpuset and user_xcpus() as an approiximation for the > target effective_cpus as the real effective_cpus hasn't been fully > computed yet as this early stage. > > As the check isn't comprehensive, there may be false positives or > negatives. We may have to revise the code to do a more thorough check > in the future if this becomes a concern. > > [1] https://lore.kernel.org/lkml/82be06c1-6d6d-4651-86c9-bcc828cbcb80@redhat.com/T/#t > > Signed-off-by: Waiman Long Applied to cgroup/for-6.13. Thanks. -- tejun