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 E5B2D19995E; Fri, 11 Jul 2025 22:15:08 +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=1752272109; cv=none; b=pgJAWT6R/l3UF1x4/t4ZodUrWltCfD0T+zaoUJaN5nVTmgxfcn438czZyNlyGxyAE91Sq+22TNmE/B0YHY5bWztgLkQska8rXeT1dzfYL0kaWKJK7lpPyaWxYETshFn/mEd5FkY8zQz6CsB5v/gNwLPZ86c7wIE90DtFlV2QaoA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752272109; c=relaxed/simple; bh=BtEQsXN690+VRsFBfvRT/wZ3UIDsKp2OxTYosAsXnAE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Ye9wOZY+hoi3L++pZRcqCEnGlNWxXAjKt4RnBMspbFdL4nrMG/8Kq5KALTjT0PDN+u/4BWL2hIFgAcnaxuXIpd8DDMrN6pFsS/pqAocG9jtRIMCCXWzDND+66RMd6xcRSSaoEnSiuQZfE27juLUOZluUhlByAaaiXntym1rmlFk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YUVpqo7Y; 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="YUVpqo7Y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C687C4CEED; Fri, 11 Jul 2025 22:15:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752272108; bh=BtEQsXN690+VRsFBfvRT/wZ3UIDsKp2OxTYosAsXnAE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YUVpqo7YIli6QJVeQfZlT5gOAr7WLxWr8FqAVyU/brJA8ScMFt8u/xKvANNh4Cuy0 JNs1riyORN9FuEtA/u2bZE4JpgP44IZ26wCnQxd1Iztie1foy8Wjpw54/2r4LEVrDr v2A7TFHVxmp5lMPHApZrYjkObKmE0UF3E1GrzBiVJfrpE9zAsRdeeMGhzvIxtV9rQl LGmKq90qLox/+bBoOeHBpJTWIRbyhgLlewnp0qweguGCMS8y2FDl38VcEcBYROmmKW coJgGd0gQ+bai1Iuf8+oH/uRqZNv0P8vEEog1n/hYI8mk65rNynGizdrTVYoEVy2zX SPLk5IwMELUtA== Date: Fri, 11 Jul 2025 12:15:07 -1000 From: Tejun Heo To: Michal =?iso-8859-1?Q?Koutn=FD?= Cc: Ben Hutchings , cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Zefan Li , Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , Andrew Morton , Chen Ridong , 1108294@bugs.debian.org Subject: Re: [PATCH 4/4] cgroup: Do not report unavailable v1 controllers in /proc/cgroups Message-ID: References: <20240909163223.3693529-1-mkoutny@suse.com> <20240909163223.3693529-5-mkoutny@suse.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=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Fri, Jul 11, 2025 at 03:10:44PM +0200, Michal Koutný wrote: > Hello Ben. > > On Wed, Jul 09, 2025 at 08:22:09PM +0200, Ben Hutchings wrote: > > Would you consider reverting this change for the sake of compatibility? > > As you write, it's not fatally broken and it may be "just" an issue of > container images that got no fresh rebuild. (And I think it should be > generally discouraged running containers with stale deps in them.) > > The original patch would mainly serve legacy userspace (host) setups on > top of contemporary kernel (besides API purity reasons). Admittedly, > these should be rare and eventually extinct in contrast with your > example where it's a containerized userspace (which typically could do > no cgroup setup) that may still have some user demand. > > So, I'd be more confident with the revert if such an adjustment was > carried downstream by some distro and proven its viability first. Do you > know of any in the wild? I think we still want to deprecate /proc/cgroups but given that there are impacted users maybe we can bring it back under a boottime param w/ warning? Thanks. -- tejun