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 4ECB4156F39 for ; Sat, 30 Nov 2024 15:47:44 +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=1732981665; cv=none; b=NXvXcqGnHVte+001jiFDP30MaezWXtkaMmyFC7IP4nFdpYsYwvSoMz/22Fx9Bt67h6W6yjv6LfOSWXKCjphAqeZqOWANabEOgw/BOmeHScgetsajlIewo08eCnJEJ2D+AWH9NGz7FSMCplGchtzQfzsEfZWSbwjXeVwp6v2t5hQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732981665; c=relaxed/simple; bh=gvsgkRpV5gtRvX7h43nQgO570L21lodn18gpEOP83Lk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fp3kq0wZqs1XWh4YGxxp80GOLEfiW+quq/cy7ySDdQueoLngYzHR2Dyr8/8i3XyUfhlPquQ07Om60WrEn3hF2dJIioGj6/45DRavUcKHgk5j6DUtqmV82dMVrgLBci9NmrqJQV07CMVH78ykfSwVW+fwcxEfDjhBQdP+YAnPfBo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=onbNBJdk; 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="onbNBJdk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 311D6C4CECC; Sat, 30 Nov 2024 15:47:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1732981664; bh=gvsgkRpV5gtRvX7h43nQgO570L21lodn18gpEOP83Lk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=onbNBJdk7+JpKUaxfZhcz682ElSQIx6eSGVzU9Awe9GknV3YaENQpQwcadRu/OohB vTdlw5oF2dV+9tzqIDIqWRxt9QL7xStDeZGv9ylQmWUQReTl/tXf88Jm0QwJnRTpNo TxSoWzk2eFAlybTnzXf/f3PY3/fJZ5DMOoQLy06U= Date: Sat, 30 Nov 2024 16:47:41 +0100 From: Greg Kroah-Hartman To: Jeremi Piotrowski Cc: stable@vger.kernel.org, Minchan Kim , Sasha Levin , Tejun Heo Subject: Re: [PATCH 5.15] kernfs: switch global kernfs_rwsem lock to per-fs lock Message-ID: <2024113006-tarot-justice-aa34@gregkh> References: <20241129113236.209845-1-jpiotrowski@linux.microsoft.com> <2024112923-constrict-respect-a0a6@gregkh> <95cf11dc-6771-4a53-9c34-20ee27bfeaa2@linux.microsoft.com> Precedence: bulk X-Mailing-List: stable@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: <95cf11dc-6771-4a53-9c34-20ee27bfeaa2@linux.microsoft.com> On Fri, Nov 29, 2024 at 10:20:48PM +0100, Jeremi Piotrowski wrote: > > And why not just switch them to 6.1.y kernels or newer? > > I wish we could just do that. Right now all our users are on 5.15 and a lot of their > workloads are sensitive to changes to any part of the container stack including kernel > version. So they will gradually migrate to kernel 6.1.y and newer as part of upgrading > their clusters to a new kubernetes release after they validate their workloads on it. > This is a slow process and in the meantime they are hitting the issue that the patch > addresses. I'm sure there are other similar users of 5.15 out there. If they are "hitting this issue" then that is the perfect reason for them to migrate off of that kernel version. Don't think that modifying a core kernel functionality like this is somehow any more "safe" than moving to a newer kernel (especially given all of the unfixed issues in the 5.15.y branch compared to 6.1.y). Saying "your workload is causing problems on this kernel version, please move to a newer one to resolve the issue." is a valid thing to tell customers. Try that first please. thanks, greg k-h