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 A4221208D7; Wed, 24 Jul 2024 05:23:23 +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=1721798603; cv=none; b=PQLU9ylJWRTGszLdXbTgMWATvK9GUbYEXlTbqaSmRswgGD63vA1flbGr3Opu9H6F3b1eeTl6ml7zg4piKPv66bLE71BjNH6NwYyaObhEwIj7uDkyD3huiu+bRH+Q1JyohqJrqp4xT0R9gjfwEhkPh+Biw3Vj8Bb3sWe286CmyTQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721798603; c=relaxed/simple; bh=3wV2E0ms8osbGVrmUy0Brt3tv3Cz24uYw20q/7UoYC0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QXD4nQio9L35oKR6npiy3CTlWGVsIfBBtEiEBN1SL/TB/DLAqBmfDxFa8o5OfPat4qoZ9bd7807ue5Mi2DMtjp/GiymgVyYZTomDKui7dpxhQ+Y74G7cseFPxnH9OHm2bhgpB9tGE8t2sa0tOxHQvhPJCFWXBky5AxMvg+fs3wk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=flYDGCor; 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="flYDGCor" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8C842C32782; Wed, 24 Jul 2024 05:23:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1721798603; bh=3wV2E0ms8osbGVrmUy0Brt3tv3Cz24uYw20q/7UoYC0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=flYDGCorY3DfjswUyJ7VkLQqocbFjGWk04Z9iiP5A6UMBwOz79ypi0iMuQ/qF9s3T jJJeslhHF98t/EM9/rYLaDXT7pmNf1oKhmRUTXlV9pkeube9/35zb7liLMe8kUOaQg s+GxlCwxIgzp5zW0N339ii8UtvsJOP4IT8Nb6hlg= Date: Wed, 24 Jul 2024 07:23:20 +0200 From: Greg KH To: WangYuli Cc: stable@vger.kernel.org, sashal@kernel.org, yi.zhang@huawei.com, jack@suse.cz, tytso@mit.edu, adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com, niecheng1@uniontech.com, zhangdandan@uniontech.com, guanwentao@uniontech.com, chenyichong@uniontech.com, wentao@uniontech.com Subject: Re: [PATCH v2 4.19 0/4] ext4: improve delalloc buffer write performance Message-ID: <2024072434-clunky-ninja-89fa@gregkh> References: <78C2D546AD199A57+20240720160420.578940-1-wangyuli@uniontech.com> <2024072316-thirty-cytoplasm-2b81@gregkh> <206F8E88DD4C4DD9+5197bc65-d440-4ad5-8b19-e1f83f4a1c7a@uniontech.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: <206F8E88DD4C4DD9+5197bc65-d440-4ad5-8b19-e1f83f4a1c7a@uniontech.com> On Wed, Jul 24, 2024 at 12:55:52PM +0800, WangYuli wrote: > Hi greg k-h, > > As a commercial Linux distribution maintainer, we understand that > even though upstream support for linux-4.19.y is ending, our users' > reliance on this kernel version will not cease immediately. Good luck to them, given that almost immediately after it goes out of support it will become insecure :( > They often lack the time or resources to promptly migrate all their > devices to a newer kernel, due to considerations such as stability, > operational costs, and other factors. They have had 6 years to plan for this, how much time do they need? > Therefore, to provide a more graceful conclusion to the linux-4.19.y > lifecycle, we propose backporting these performance optimizations > to extend its useful life  and ensure a smooth transition for commercial > users by the way. Performance optimizations for old kernels like this are not a good idea, please just have them move to a more modern, and actually supported, kernel instead if they wish to have performance improvements. Otherwise you are ensuring they will never move. good luck! greg k-h