From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266445AbUHIJ5z (ORCPT ); Mon, 9 Aug 2004 05:57:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266443AbUHIJ5z (ORCPT ); Mon, 9 Aug 2004 05:57:55 -0400 Received: from [195.23.16.24] ([195.23.16.24]:18399 "EHLO bipbip.comserver-pie.com") by vger.kernel.org with ESMTP id S266445AbUHIJ5q (ORCPT ); Mon, 9 Aug 2004 05:57:46 -0400 Message-ID: <41174A95.3050705@grupopie.com> Date: Mon, 09 Aug 2004 10:57:41 +0100 From: Paulo Marques Organization: Grupo PIE User-Agent: Mozilla Thunderbird 0.7.1 (X11/20040626) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Hamie Cc: Alan Cox , Russell King , Linux Kernel Mailing List Subject: Re: ide-cs using 100% CPU References: <40FA4328.4060304@travellingkiwi.com> <20040806202747.H13948@flint.arm.linux.org.uk> <4113DD20.1010808@travellingkiwi.com> <1091917597.19077.38.camel@localhost.localdomain> <4115EC6C.5040608@travellingkiwi.com> In-Reply-To: <4115EC6C.5040608@travellingkiwi.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-AntiVirus: checked by Vexira MailArmor (version: 2.0.1.16; VAE: 6.26.0.10; VDF: 6.26.0.64; host: bipbip) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hamie wrote: > Alan Cox wrote: > >> On Gwe, 2004-08-06 at 20:33, Hamie wrote: >> >> >>> Is 100% CPU not excessive? IIRC my PIII-750 used to use less CPU >>> doing the same job as quick, or even slightly faster... >>> >> >> >> PCMCIA IDE is PIO only so it burns CPU. This is one case where >> hyperthreading is nice. Cardbus IDE is a lot better but very little >> exists and we don't currently support hotplug IDE controllers. >> >> >> > > Ah right. But would a CF memory card be cardbus anyway? I've never seen a CF card that supported DMA (and I've worked with several brands). Compact Flash cards have several modes of operation and only one of this modes is "IDE-compatible". > >>> And should it not use system CPU rather than user CPU? >>> >> >> >> Yes - but figure out please if the kernel or userspace is getting that >> wrong ;) >> >> >> > > My apologies. It was gkrellm leading me up the garden path on that > one... Copying about 100MB from a 512MB CF card (25+ photos from my > camera) vmstat 5 reports 4% usercpu, 96% system cpu. And the response on > the system is sluggish to say the least. (Moving the pointer in X is > painful :). gkrell meanwhile on it's cpu graph shows about 30% system, > and the rest as userCPU. No idea why, I guess till I find out I'll just > regard gkrellm's cpu graph as a waste of space (To differentiate system > & user cpu anyway :). I think this is more of a scheduler/priorities problem. Maybe all the work that is being done with staircase / low-latency will help you on this :) -- Paulo Marques - www.grupopie.com "In a world without walls and fences who needs windows and gates?"