From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753345Ab3JVNok (ORCPT ); Tue, 22 Oct 2013 09:44:40 -0400 Received: from mail-ve0-f196.google.com ([209.85.128.196]:61927 "EHLO mail-ve0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751446Ab3JVNoi (ORCPT ); Tue, 22 Oct 2013 09:44:38 -0400 MIME-Version: 1.0 Date: Tue, 22 Oct 2013 21:44:36 +0800 Message-ID: Subject: A thought about IO scheduler in linux kernel for SSD From: =?GB2312?B?uqvA2g==?= To: linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Nowadays,the IO schedulers in linux kernel have four types: deadline,noop,Anticiptory and CFQ.CFQ is the default scheduler.But CFQ is not a good scheduler for SSD,dealine may be a good choice. When deadline runs,it has a mount of computation about merging and sorting.Merge has three types: front_merge,no_merge and back_merge. Why don't have another type: merge based same sector.For example,it have two bios in a request list,theyboth have the same bi->sector,the bi->size maybe not equal. Whether can we put the latter bio replace the former?What do you find that significant?Or the other levels in OS has finished this function?