From mboxrd@z Thu Jan 1 00:00:00 1970 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.subspace.kernel.org (Postfix) with ESMTPS id 8BACD207A36; Fri, 11 Oct 2024 09:18:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728638294; cv=none; b=YWxkfmRwekJaJVudJ0lDyYtoZc15Z6505ud+mf8McbKQJRAp5Bt03Lrnd1RxTAJu0CZjkwsyCcegKvvdMGzKNNNZYT231LwZIqljbTXZZMCDSk5xUQED/s2ffv6KOimQJBlA5jGZQgQQ+C6/Kfaher4SKcf+t1EZkgtvjbmwzLU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1728638294; c=relaxed/simple; bh=m2Llmirs7gZ+YvRTkAP1OLo1mBvaOWjgJWGJGgqeTJ4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=F4i9BqM9qB/KYYMyBY2QUq81ufoOKlg9g1b9dnavRSb7h9Sz0gLzPpUTv7JLGlHM6+9OcOjGoUjLRad7DesVQD2My8XHXWa+5fJI4QOPOxZskABsv7PCoCzjCimH3S1+4npiBEWpk7HW9V3winIRDojBkbMWfvTsJUSyFKCC+zc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=Quf8GJzg; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Quf8GJzg" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=lU4r4tbL0K3+5Mx7gnspEYb/vcINY3gT5cXeOgb5F4w=; b=Quf8GJzgeSqTUbUf2AO61bq2LU Vf+sqE1ISUAtcou7pFQzSVWv9InCaQKBoNd0afkNiv10L1mfVdLAfuZqdRMl/eVzwvg1LIjnPSgRK bKGLaoP6oKtAZ0+iIW2SuFuA9IX5rlhBRy2PApzCAuKxL5P39veXhGyuBZikJB5HCpCMvAy/RPwhk x+iQBynF6YG1b170b2ADWCDkmbV+l3SIixwMM+ABeReVdPFfffqfyxC8IpG4uEF7f5C0GB0e8yg9O ROhve62AuLOSgCtv0FBgCduv+2YocVTwKa+gGZ5aSE9GPjg+5J5xpstuLLxyrAoBK+jWMzLm2wGew PN1kCL1w==; 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> 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: <20241011091133.28173-1-qun-wei.lin@mediatek.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html 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.