Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267460AbUIBFfn (ORCPT ); Thu, 2 Sep 2004 01:35:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267520AbUIBFfn (ORCPT ); Thu, 2 Sep 2004 01:35:43 -0400 Received: from mx1.elte.hu ([157.181.1.137]:49074 "EHLO mx1.elte.hu") by vger.kernel.org with ESMTP id S267460AbUIBFfm (ORCPT ); Thu, 2 Sep 2004 01:35:42 -0400 Date: Thu, 2 Sep 2004 07:37:19 +0200 From: Ingo Molnar To: "K.R. Foley" Cc: linux-kernel@vger.kernel.org, Mark_H_Johnson@raytheon.com, Lee Revell Subject: Re: [patch] voluntary-preempt-2.6.9-rc1-bk4-Q7 Message-ID: <20040902053719.GA12684@elte.hu> References: <1093727453.8611.71.camel@krustophenia.net> <20040828211334.GA32009@elte.hu> <1093727817.860.1.camel@krustophenia.net> <1093737080.1385.2.camel@krustophenia.net> <1093746912.1312.4.camel@krustophenia.net> <20040829054339.GA16673@elte.hu> <20040830090608.GA25443@elte.hu> <20040901082958.GA22920@elte.hu> <20040901135122.GA18708@elte.hu> <41367E5D.3040605@cybsft.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <41367E5D.3040605@cybsft.com> User-Agent: Mutt/1.4.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 800 Lines: 21 * K.R. Foley wrote: > This is an interesting one. ~3.9ms generated here by amlat in do_IRQ: the overhead is not in do_IRQ(): > 00000001 0.000ms (+0.000ms): n_tty_receive_buf (pty_write) > 00010001 3.992ms (+3.992ms): do_IRQ (n_tty_receive_buf) the overhead is always relative to the previous entry - so the overhead was in n_tty_receive_buf() [that is the function that was interrupted by do_IRQ()]. But it's a bit weird - you should have gotten timer IRQs every 1 msec. Does n_tty_receive_buf() run with irqs disabled perhaps? Ingo - 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/