From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id C52256B0005 for ; Sun, 8 May 2016 05:01:17 -0400 (EDT) Received: by mail-pf0-f199.google.com with SMTP id b203so320157449pfb.1 for ; Sun, 08 May 2016 02:01:17 -0700 (PDT) Received: from bombadil.infradead.org (bombadil.infradead.org. [2001:1868:205::9]) by mx.google.com with ESMTPS id 145si29846251pfy.175.2016.05.08.02.01.17 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 08 May 2016 02:01:17 -0700 (PDT) Date: Sun, 8 May 2016 02:01:15 -0700 From: "hch@infradead.org" Subject: Re: [PATCH v4 5/7] fs: prioritize and separate direct_io from dax_io Message-ID: <20160508090115.GE15458@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> <20160505152230.GA3994@infradead.org> <1462484695.29294.7.camel@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1462484695.29294.7.camel@intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: "Verma, Vishal L" Cc: "Williams, Dan J" , "hch@infradead.org" , "linux-kernel@vger.kernel.org" , "linux-block@vger.kernel.org" , "xfs@oss.sgi.com" , "linux-nvdimm@ml01.01.org" , "linux-mm@kvack.org" , "viro@zeniv.linux.org.uk" , "axboe@fb.com" , "akpm@linux-foundation.org" , "linux-fsdevel@vger.kernel.org" , "linux-ext4@vger.kernel.org" , "david@fromorbit.com" , "jack@suse.cz" , "matthew@wil.cx" On Thu, May 05, 2016 at 09:45:07PM +0000, Verma, Vishal L wrote: > I'm not sure I completely understand how this will work? Can you explain > a bit? Would we have to export rw_bytes up to layers above the pmem > driver? Where does get_user_pages come in? A DAX filesystem can directly use the nvdimm layer the same way btt doe,s what's the problem? Re get_user_pages my idea was to simply use that to lock down the user pages so that we can call rw_bytes on it. How else would you do it? Do a kmalloc, copy_from_user and then another memcpy? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org