From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id 586C77CB1 for ; Tue, 2 Feb 2016 10:42:44 -0600 (CST) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay3.corp.sgi.com (Postfix) with ESMTP id D65B2AC007 for ; Tue, 2 Feb 2016 08:42:40 -0800 (PST) Received: from newverein.lst.de (verein.lst.de [213.95.11.211]) by cuda.sgi.com with ESMTP id HyQtwyWoTbtDqajh (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Tue, 02 Feb 2016 08:42:38 -0800 (PST) Date: Tue, 2 Feb 2016 17:42:37 +0100 From: Christoph Hellwig Subject: Re: stop using ioends for direct write completions Message-ID: <20160202164237.GA25436@lst.de> References: <1452766237-2314-1-git-send-email-hch@lst.de> <20160128131656.GB14876@infradead.org> <20160129141232.GA43184@bfoster.bfoster> <20160202112046.GB28777@lst.de> <20160202153117.GB1853@bfoster.bfoster> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20160202153117.GB1853@bfoster.bfoster> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Brian Foster Cc: darrick.wong@oracle.com, xfs@oss.sgi.com On Tue, Feb 02, 2016 at 10:31:18AM -0500, Brian Foster wrote: > FWIW, I don't see any such review comments against the three versions of > the "DIO needs an ioend for writes" patch I have in my mailbox, but I > easily could have missed something..? But if there wasn't time, then > fair enough. I'll have to look at the mailboxes, but I remember Dave sending this out and complaining. > I'm just looking for context. I don't have much of an opinion on which > approach is used here. If it simplifies COW, then that seems good enough > reason to me to take this approach. I'm pointing this out more because > this code seems to have been rewritten the last couple of times we > needed to fix something, which makes backports particularly annoying. > The two patches above were associated with a broader enhancement and a > bug fix (respectively) as a sort of justification, whereas this post had > a much more vague purpose from what I could tell, and therefore why I at > least hadn't taken the time to review it. > > If COW is the primary motivator, perhaps we can bundle it with that > work? The prime motivator is to: (1) avoid a pointless memory allocation (2) avoid a pointless context switch (3) avoid pointless code complexity COW is just another case where these show up. _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs