From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752135Ab2IUEfe (ORCPT ); Fri, 21 Sep 2012 00:35:34 -0400 Received: from ares07.inai.de ([5.9.24.206]:60556 "EHLO seven.medozas.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751767Ab2IUEfc (ORCPT ); Fri, 21 Sep 2012 00:35:32 -0400 Date: Fri, 21 Sep 2012 06:35:30 +0200 (CEST) From: Jan Engelhardt To: Tatyana Brokhman cc: axboe@kernel.dk, Jeff Moyer , linux-arm-msm@vger.kernel.org, "open list:DOCUMENTATION" , open list Subject: Re: [RFC/PATCH 2/2] block: Adding ROW scheduling algorithm In-Reply-To: Message-ID: References: <1344166241-18708-1-git-send-email-tlinder@codeaurora.org> <1344166241-18708-3-git-send-email-tlinder@codeaurora.org> User-Agent: Alpine 2.01 (LNX 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 2012-09-19 07:29, Jan Engelhardt wrote: >On Monday 2012-08-06 18:35, Jeff Moyer wrote: >>Tatyana Brokhman writes: >> >>> This patch adds the implementation of a new scheduling algorithm - ROW. >>> The policy of this algorithm is to prioritize READ requests over WRITE >>> as much as possible without starving the WRITE requests. >> >>Perhaps you could start off by describing the workload, and describing >>why the existing I/O schedulers do not perform well. There seems to a bug with ROW. After about 43 hours of continued operation, programs (./configure was what I ran at the time this happened) first become slow, then got stuck in D state within a minute. Ctrl-C/Z worked at first, soon not, then these messages appeared in dmesg. [319952.630605] row: forced dispatching is broken (nr_sorted=17), please report this [319952.631174] row: forced dispatching is broken (nr_sorted=17), please report this