From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f173.google.com (mail-pd0-f173.google.com [209.85.192.173]) by kanga.kvack.org (Postfix) with ESMTP id 5CC956B0035 for ; Fri, 25 Apr 2014 10:01:11 -0400 (EDT) Received: by mail-pd0-f173.google.com with SMTP id p10so2829288pdj.4 for ; Fri, 25 Apr 2014 07:01:11 -0700 (PDT) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTP id sf3si4900161pac.370.2014.04.25.07.01.09 for ; Fri, 25 Apr 2014 07:01:10 -0700 (PDT) Date: Fri, 25 Apr 2014 10:01:01 -0400 From: Matthew Wilcox Subject: Re: [PATCH v3 5/7] swap: Use bdev_read_page() / bdev_write_page() Message-ID: <20140425140100.GF5886@linux.intel.com> References: <9fb0b4031b0fba312963a7cc21bf258d944cddcf.1397429628.git.matthew.r.wilcox@intel.com> <20140424111817.9cc62b2ff1e368c5cf27d262@linux-foundation.org> <20140424185740.GE5886@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140424185740.GE5886@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Matthew Wilcox , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Hugh Dickins On Thu, Apr 24, 2014 at 02:57:40PM -0400, Matthew Wilcox wrote: > By calling the device driver to write the page directly, we avoid > allocating a BIO, which allows us to free memory without allocating > memory. I got handed some performance numbers last night! Next time you're updating the patch description, please use: By calling the device driver to write the page directly, we avoid allocating a BIO, which allows us to free memory without allocating memory. When running a swap-heavy benchmark, system time is reduced by about 20%. Tested-by: Dheeraj Reddy Signed-off-by: Matthew Wilcox -- 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