From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from newverein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id D43A82095DB91 for ; Mon, 31 Jul 2017 00:15:01 -0700 (PDT) Date: Mon, 31 Jul 2017 09:17:07 +0200 From: Christoph Hellwig Subject: Re: [PATCH 0/3] remove rw_page() from brd, pmem and btt Message-ID: <20170731071707.GA16299@lst.de> References: <20170728165604.10455-1-ross.zwisler@linux.intel.com> <20170728173143.GE15980@bombadil.infradead.org> <20170728142123.729b20e9fcf45c6a814f18e7@linux-foundation.org> <20170730221659.GA28031@bbox> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20170730221659.GA28031@bbox> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Minchan Kim Cc: Jens Axboe , Jerome Marchand , linux-nvdimm@lists.01.org, Dave Chinner , linux-kernel@vger.kernel.org, Matthew Wilcox , Christoph Hellwig , seungho1.park@lge.com, Jan Kara , Andrew Morton , "karam . lee" , Nitin Gupta List-ID: On Mon, Jul 31, 2017 at 07:16:59AM +0900, Minchan Kim wrote: > rw_page's gain is reducing of dynamic allocation in swap path > as well as performance gain thorugh avoiding bio allocation. > And it would be important in memory pressure situation. There is no need for any dynamic allocation when using the bio path. Take a look at __blkdev_direct_IO_simple for an example that doesn't do any allocations. _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm