Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751278AbVJRUZz (ORCPT ); Tue, 18 Oct 2005 16:25:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751483AbVJRUZz (ORCPT ); Tue, 18 Oct 2005 16:25:55 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:5351 "EHLO mx2.mail.elte.hu") by vger.kernel.org with ESMTP id S1751278AbVJRUZz (ORCPT ); Tue, 18 Oct 2005 16:25:55 -0400 Date: Tue, 18 Oct 2005 22:26:10 +0200 From: Ingo Molnar To: Daniel Walker Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , david singleton , Steven Rostedt , Rui Nuno Capela , Fernando Lopez-Lezcano , Mark Knecht Subject: Re: 2.6.14-rc4-rt7 Message-ID: <20051018202610.GA12375@elte.hu> References: <20051017160536.GA2107@elte.hu> <20051018064259.GA21236@elte.hu> <1129652611.13672.12.camel@c-67-188-6-232.hsd1.ca.comcast.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1129652611.13672.12.camel@c-67-188-6-232.hsd1.ca.comcast.net> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamScore: 0.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=0.0 required=5.9 tests=AWL autolearn=disabled SpamAssassin version=3.0.4 0.0 AWL AWL: From: address is in the auto white-list X-ELTE-VirusStatus: clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1222 Lines: 28 * Daniel Walker wrote: > > > I found this latency ~5 minutes after boot up, no load . It looks like > > > vgacon_scroll() has a memset like operation which can grow. > > > > do you have PRINTK_IGNORE_LOGLEVEL enabled? If yes then much of the > > printk code will run with interrupts disabled - hence non-preemptable. > > PRINTK_IGNORE_LOGLEVEL is a debugging feature for developers. I have > > added an extra explanation to the Kconfig, see below. > > I was just running a "make defconfig" and I enabled latency tracing . > PRINTK_IGNORE_LOGLEVEL defaults to off (doesn't it?), and I didn't > make any changes to it . Unless it get switched on by something else > .. > > It looks like the logic might be reversed in release_console_sem() . yeah, it is reversed. I 'fixed' it a couple of releases ago - but in fact it was correct previously and i introduced this bug. I have fixed this in my tree and have released -rt9 with the fix. 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/