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 07BE47CA2 for ; Wed, 15 Jun 2016 09:56:43 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay3.corp.sgi.com (Postfix) with ESMTP id 75101AC002 for ; Wed, 15 Jun 2016 07:56:42 -0700 (PDT) Received: from bombadil.infradead.org ([198.137.202.9]) by cuda.sgi.com with ESMTP id pkhbDMQGGqJ5mIeI (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO) for ; Wed, 15 Jun 2016 07:56:40 -0700 (PDT) Date: Wed, 15 Jun 2016 07:56:38 -0700 From: Christoph Hellwig Subject: Re: [PATCH 10/12] NFS: Do not serialise O_DIRECT reads and writes Message-ID: <20160615145638.GC5297@infradead.org> References: <1465931115-30784-5-git-send-email-trond.myklebust@primarydata.com> <1465931115-30784-6-git-send-email-trond.myklebust@primarydata.com> <1465931115-30784-7-git-send-email-trond.myklebust@primarydata.com> <1465931115-30784-8-git-send-email-trond.myklebust@primarydata.com> <1465931115-30784-9-git-send-email-trond.myklebust@primarydata.com> <1465931115-30784-10-git-send-email-trond.myklebust@primarydata.com> <20160615071343.GC4318@infradead.org> <755A2A14-C6A9-4737-8335-0A6785490F6D@primarydata.com> <20160615144801.GB18524@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: 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: Trond Myklebust Cc: Christoph Hellwig , "linux-nfs@vger.kernel.org" , "xfs@oss.sgi.com" On Wed, Jun 15, 2016 at 02:52:24PM +0000, Trond Myklebust wrote: > >But XFS allows full parallelism for direct reads and writes as long > >as there is no more pagecache to flush. But if you have pages in > >the pagecache you need the exclusive lock to prevent against new > >pagecache pages being added. > > Exactly. So does this. So let's avoid bloating the inode with another rw_semaphore, and make everyones life easier by using the existing lock. > We don???t use generic_file_* for O_DIRECT; we only use it for buffered I/O. I know - this was just an answer to your reference to the generic_file_* code. _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs