From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 56A7FCFD2FD for ; Fri, 11 Oct 2024 09:19:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=lU4r4tbL0K3+5Mx7gnspEYb/vcINY3gT5cXeOgb5F4w=; b=KKo+2qygF+gjt0GJtdRbMqgJU7 8cOpdT4zQPd3aE3xETWh7IbKTesTY7sERCv4S5+Rl6Hz77kAnp33my/1W7UXSdpKCw7YFk/g3M4yY MwCQgRg1S+13GadsZKlSBXwOE4x7hfMQ0+Kl3BvQRaC9R+HWwIJ9p/e5GDgrjNYGA1BWf/+OOHBHd iTkzPl7aU8saWM3L21O2ZIfKccJmLZj4L5wMA2pTJBmrVQD3HYmAgs4BvsNx4IKLu0sLskjQ/IB25 Z/ZGWuXiiW08hF/Hey6PzsIGT6QkfUACARXAsACNn2OG+dbUkPyQ4PA9CwMtMYgnF3KJPSQDms/EX +ro+52LA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1szBo8-0000000Fo9m-3R5n; Fri, 11 Oct 2024 09:19:37 +0000 Received: from hch by bombadil.infradead.org with local (Exim 4.98 #2 (Red Hat Linux)) id 1szBmb-0000000FnpU-3CEE; Fri, 11 Oct 2024 09:18:01 +0000 Date: Fri, 11 Oct 2024 02:18:01 -0700 From: Christoph Hellwig To: Qun-Wei Lin Cc: Jens Axboe , Minchan Kim , Sergey Senozhatsky , Vishal Verma , Dan Williams , Dave Jiang , Ira Weiny , Andrew Morton , Matthias Brugger , AngeloGioacchino Del Regno , "Huang, Ying" , Chris Li , Ryan Roberts , David Hildenbrand , Kairui Song , "Matthew Wilcox (Oracle)" , Dan Schatzberg , Barry Song , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, nvdimm@lists.linux.dev, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Casper Li , Chinwen Chang , Andrew Yang , John Hsu , wsd_upstream@mediatek.com Subject: Re: [PATCH] mm: Split BLK_FEAT_SYNCHRONOUS and SWP_SYNCHRONOUS_IO into separate read and write flags Message-ID: References: <20241011091133.28173-1-qun-wei.lin@mediatek.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241011091133.28173-1-qun-wei.lin@mediatek.com> X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Oct 11, 2024 at 05:11:33PM +0800, Qun-Wei Lin wrote: > This patch splits the BLK_FEAT_SYNCHRONOUS feature flag into two > separate flags: BLK_FEAT_READ_SYNCHRONOUS and > BLK_FEAT_WRITE_SYNCHRONOUS. Similarly, the SWP_SYNCHRONOUS_IO flag is > split into SWP_READ_SYNCHRONOUS_IO and SWP_WRITE_SYNCHRONOUS_IO. > > These changes are motivated by the need to better accommodate certain > swap devices that support synchronous read operations but asynchronous write > operations. > > The existing BLK_FEAT_SYNCHRONOUS and SWP_SYNCHRONOUS_IO flags are not > sufficient for these devices, as they enforce synchronous behavior for > both read and write operations. You're still failing to provide a user. Without that it is dead in the water from the very beginning.