Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 22 Nov 2000 06:30:07 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 22 Nov 2000 06:29:57 -0500 Received: from fgwmail7.fujitsu.co.jp ([192.51.44.37]:54758 "EHLO fgwmail7.fujitsu.co.jp") by vger.kernel.org with ESMTP id ; Wed, 22 Nov 2000 06:29:46 -0500 From: kumon@flab.fujitsu.co.jp Date: Wed, 22 Nov 2000 19:59:38 +0900 Message-Id: <200011221059.TAA03907@asami.proc.flab.fujitsu.co.jp> To: Jens Axboe Cc: kumon@flab.fujitsu.co.jp, linux-kernel@vger.kernel.org, Dave Jones , Andrea Arcangeli Subject: Re: [PATCH] livelock in elevator scheduling In-Reply-To: <20001121112836.B10007@suse.de> In-Reply-To: <200011210838.RAA27382@asami.proc.flab.fujitsu.co.jp> <20001121112836.B10007@suse.de> Reply-To: kumon@flab.fujitsu.co.jp Cc: kumon@flab.fujitsu.co.jp X-Mailer: Handmade Mailer version 1.0 Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Jens Axboe writes: > I'd be very interested if you could repeat your test with my > block patch applied. It has, among other things, a more fair (and > faster) insertion. > > *.kernel.org/pub/linux/kernel/people/axboe/patches/2.4.0-test11/blk-11.bz2 This patch fixes the "DoS" behavior of the current queuing mechanism. Even if I set the "pass-over" values to very large number (1000000) it stably runs. Thank you for your patch. >From my understanding, passover is an option of the elevator scheduling to prioritize long waiting requests for improving online responses. In that test, passover value setting doesn't affect the benchmark number, which is probable. Will the patch is included in the next kernel? BTW, The major performance difference between test1 and test2 was caused by whether the hard_dirty_limit is hit or not. The current Linux has a lot of difficult to set parameters in /proc/sys. Once a system goes beyond some settable limits, the system behavior changes so sharp. Bdf_prm.nrfract in fs/buffer.c is one of the difficult parameters. I hope a tool to monitor or set these value. -- Computer Systems Laboratory, Fujitsu Labs. kumon@flab.fujitsu.co.jp - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/