From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751054AbcEHJBv (ORCPT ); Sun, 8 May 2016 05:01:51 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:45362 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750913AbcEHJBt (ORCPT ); Sun, 8 May 2016 05:01:49 -0400 Date: Sun, 8 May 2016 02:01:48 -0700 From: "hch@infradead.org" To: "Verma, Vishal L" Cc: "hch@infradead.org" , "boaz@plexistor.com" , "linux-kernel@vger.kernel.org" , "linux-block@vger.kernel.org" , "linux-nvdimm@ml01.01.org" , "xfs@oss.sgi.com" , "linux-mm@kvack.org" , "viro@zeniv.linux.org.uk" , "akpm@linux-foundation.org" , "axboe@fb.com" , "linux-fsdevel@vger.kernel.org" , "linux-ext4@vger.kernel.org" , "david@fromorbit.com" , "jack@suse.cz" , "matthew@wil.cx" Subject: Re: [PATCH v4 5/7] fs: prioritize and separate direct_io from dax_io Message-ID: <20160508090148.GF15458@infradead.org> References: <1461878218-3844-1-git-send-email-vishal.l.verma@intel.com> <1461878218-3844-6-git-send-email-vishal.l.verma@intel.com> <5727753F.6090104@plexistor.com> <20160505142433.GA4557@infradead.org> <1462484343.29294.1.camel@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1462484343.29294.1.camel@intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 05, 2016 at 09:39:14PM +0000, Verma, Vishal L wrote: > How is it any 'less direct'? All it does now is follow the blockdev > O_DIRECT path. There still isn't any page cache involved.. It's still more overhead than the play DAX I/O path.