From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755000AbaHNWE2 (ORCPT ); Thu, 14 Aug 2014 18:04:28 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:34271 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753318AbaHNWE1 (ORCPT ); Thu, 14 Aug 2014 18:04:27 -0400 Date: Thu, 14 Aug 2014 15:04:25 -0700 From: Andrew Morton To: Akinobu Mita Cc: linux-kernel@vger.kernel.org, Jens Axboe , Alexander Viro , Jeff Moyer , linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 0/3] implement readpages() for block device to optimize sequential read Message-Id: <20140814150425.dfbb6c7eb7ab250e985dac28@linux-foundation.org> In-Reply-To: <1407249514-20465-1-git-send-email-akinobu.mita@gmail.com> References: <1407249514-20465-1-git-send-email-akinobu.mita@gmail.com> X-Mailer: Sylpheed 3.2.0beta5 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 5 Aug 2014 23:38:31 +0900 Akinobu Mita wrote: > This patchset implements readpages() operation for block device by > using mpage_readpages() which can create multipage BIOs instead of > BIOs for each page and reduce system CPU time consumption. Patchset is simple and straightforward enough. But who the heck cares about the performance of buffered reads from /dev/XXX?