From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932320AbWAFAaI (ORCPT ); Thu, 5 Jan 2006 19:30:08 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932321AbWAFAaI (ORCPT ); Thu, 5 Jan 2006 19:30:08 -0500 Received: from zproxy.gmail.com ([64.233.162.201]:54582 "EHLO zproxy.gmail.com") by vger.kernel.org with ESMTP id S932320AbWAFAaF convert rfc822-to-8bit (ORCPT ); Thu, 5 Jan 2006 19:30:05 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=dXk+GtwBoIP1vKYY+L1Qvj0y1kLPmRnsyjcNZh98jffpd9YYImyJPl3Sc7mkMdhCaRFack2ZWSnK6dRhGiuc/qVbIjldIVhivXn/wp3b98f+9TMmtknIxVMrBGWxNmA6ShexsgM73v0avSpyd4aK4PazUaGU/sich3eloWwomMo= Message-ID: <86802c440601051630i4d52aa2fj1a2990acf858cd63@mail.gmail.com> Date: Thu, 5 Jan 2006 16:30:05 -0800 From: Yinghai Lu To: vgoyal@in.ibm.com, Andi Kleen Subject: Re: Inclusion of x86_64 memorize ioapic at bootup patch Cc: "Eric W. Biederman" , Fastboot mailing list , linux kernel mailing list , Morton Andrew Morton , "discuss@x86-64.org" , linuxbios@openbios.org In-Reply-To: <20060103044632.GA4969@in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline References: <20060103044632.GA4969@in.ibm.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org the patch is good. I tried LinuxBIOS with kexec. without this patch: I need to disable acpi in kernel. otherwise the kernel with acpi support can boot the second kernel, but the second kernel will hang after time.c: Using 14.318180 MHz HPET timer. time.c: Detected 2197.663 MHz processor. Console: colour VGA+ 80x25 Dentry cache hash table entries: 131072 (order: 8, 1048576 bytes) Inode-cache hash table entries: 65536 (order: 7, 524288 bytes) Memory: 1009152k/1048576k available (2967k kernel code, 39036k reserved, 1186k ) YH On 1/2/06, Vivek Goyal wrote: > Hi Andi, > > Can you please include the following patch. This patch has already been pushed > by Andrew. > > http://kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.15-rc5/2.6.15-rc5-mm3/broken-out/x86_64-io_apicc-memorize-at-bootup-where-the-i8259-is.patch > > This patch is regarding remembering at boot up time where i8259 is connected > and restore the APIC settings back during kexec boot or kdump boot. This > enables getting timer interrupts in new kernel in legacy mode. > > This patch is needed to make kexec and kdump work on some systems, > especially opteron boxes. Otherwise the second kernel does not receive > timer interrupts during early boot hence hangs. > > I understand, that you are inclined towards remembering all the APIC states > and simply restore it back instead of putting hooks. This will work > well for kexec but not for kdump because in kdump system can crash on > non-boot cpu. > > Restoring BIOS APIC state can make sure that BIOS designated boot cpu will > always be able to see timer interrupts in legacy mode but same does not > hold good if new kernel boots on some other cpu as is the case with kdump. > > In case of kexec boot, we relocate to boot cpu but in case of kdump we > don't because it was suggested that in some extreme cases of crash, boot cpu > might not respond even to NMI and relocation to boot cpu will not be > possible. > > Can you please re-consider this patch for inclusion. > > Thanks > Vivek > - > 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/ >