Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755524AbWKRNNP (ORCPT ); Sat, 18 Nov 2006 08:13:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756309AbWKRNNO (ORCPT ); Sat, 18 Nov 2006 08:13:14 -0500 Received: from moutng.kundenserver.de ([212.227.126.177]:5092 "EHLO moutng.kundenserver.de") by vger.kernel.org with ESMTP id S1756308AbWKRNNN (ORCPT ); Sat, 18 Nov 2006 08:13:13 -0500 From: Christian To: linux-kernel@vger.kernel.org Subject: Sluggish system responsiveness on I/O Date: Sat, 18 Nov 2006 14:12:29 +0100 User-Agent: KMail/1.9.5 MIME-Version: 1.0 Content-Disposition: inline X-Length: 693 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <200611181412.29144.christiand59@web.de> X-Provags-ID: kundenserver.de abuse@kundenserver.de login:176b6e6b41629db5898eee8167b5e3a0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1617 Lines: 36 Hello lkml! Im currently testing 2.6.19-rc5-mm1. Everything works really fine except the little wart with bad multimedia interactivity with a kernel compiling in the background. So I tried to narrow it down as much as possible. I did several find's,dd's and cats in parrallel and watched four instances of glxgears and also played a little enemy-territory. The interactivity was very good, in fact no loss of interactivity at all. This was contrary to what I believed the whole time. The loss of interactivity has nothing to do with heavy I/O. In fact it happens only when I run a task which is I/O and CPU heavy at the same time. That means a single kernel compile (with -j1) is able to harm interactivity with glxgears and enemy-territory, but fully loading my three disks does no harm at all. So I tried to nice the make and see what happens: nice 5 make -j4: Seems to make no difference. Heavy stuttering in glxgears and et nice 10 make -j4: Somewhat better but still unusable with et everything above nice 15 is usable. nice 19 has full interactivity, that means you can't make out a difference between no load and kernel compile while playing enemy-territory. I suspect that it has something to do with the priority boost for I/O hogs. But if this is a "general" scheduler problem, then why aren't more people complaining about this? -Christian - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/