Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753613AbXJBJqQ (ORCPT ); Tue, 2 Oct 2007 05:46:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751807AbXJBJqB (ORCPT ); Tue, 2 Oct 2007 05:46:01 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.31.123]:34621 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751733AbXJBJqA (ORCPT ); Tue, 2 Oct 2007 05:46:00 -0400 Date: Tue, 2 Oct 2007 11:45:59 +0200 From: Pavel Machek To: Thomas Gleixner Cc: "Rafael J. Wysocki" , Jeff Chua , rusty@rustycorp.com.au, vatsa@in.ibm.com, zwane@arm.linux.org.uk, kernel list , Len Brown Subject: Re: cpu hotplug support broken in 2.6.23-rc3 Message-ID: <20071002094559.GA21895@atrey.karlin.mff.cuni.cz> References: <20070903034720.GB3655@ucw.cz> <200709031219.12846.rjw@sisk.pl> <1188822917.3406.0.camel@chaos> <20070904072744.GA30474@atrey.karlin.mff.cuni.cz> <1189713695.3974.23.camel@chaos> <20070914123816.GE1671@elf.ucw.cz> <1189774257.3100.7.camel@chaos> <1189775743.3100.9.camel@chaos> <1189849781.4319.5.camel@chaos> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1189849781.4319.5.camel@chaos> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1701 Lines: 45 Hi! > > > Venki sent me an initial patch, but it has issues with the notify > > > ordering. Find below my "cache the broadcast flags" version for testing. > > > > Hmmpf, the flag is still cleared when the cpu goes offline. Need to take > > a closer look. > > I finally tracked it down. There were several ways to turn the box into > a brick. Sigh ! > > Can you please test the combo patch below ? Sorry, I was on holidays. I assume this is in -rc9 or so, already? Yes, seems so. Unfortunately, cpu hotplug seems to be still behaving strangely in -rc9. I can echo 0 > online (and cpu will go down). I do echo 0 > online, again, and I get -EBUSY. Good. But I try to do echo 1 > online, and get -EBUSY, too... and that's bad :-(. root@amd:/sys/devices/system/cpu/cpu1# echo 0 > online root@amd:/sys/devices/system/cpu/cpu1# echo 0 > online -bash: echo: write error: Device or resource busy root@amd:/sys/devices/system/cpu/cpu1# echo 1 > online -bash: echo: write error: Device or resource busy root@amd:/sys/devices/system/cpu/cpu1# uname -a Linux amd 2.6.23-rc9 #507 SMP Tue Oct 2 09:58:40 CEST 2007 i686 GNU/Linux Kernel says: Oct 2 11:42:12 amd log1n[1436]: ROOT LOGIN on `tty1' Oct 2 11:42:56 amd kernel: CPU 1 is now offline Oct 2 11:42:56 amd kernel: SMP alternatives: switching to UP code Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - 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/