Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751365AbVKSEfd (ORCPT ); Fri, 18 Nov 2005 23:35:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751353AbVKSEfd (ORCPT ); Fri, 18 Nov 2005 23:35:33 -0500 Received: from e32.co.us.ibm.com ([32.97.110.150]:50899 "EHLO e32.co.us.ibm.com") by vger.kernel.org with ESMTP id S1751365AbVKSEfc (ORCPT ); Fri, 18 Nov 2005 23:35:32 -0500 Date: Sat, 19 Nov 2005 10:05:23 +0530 From: Vivek Goyal To: "Eric W. Biederman" Cc: linux kernel mailing list , Morton Andrew Morton , Fastboot mailing list , ak@suse.de Subject: Re: [PATCH 8/10] kdump: x86_64 save cpu registers upon crash Message-ID: <20051119043523.GB3665@in.ibm.com> Reply-To: vgoyal@in.ibm.com References: <20051117131339.GD3981@in.ibm.com> <20051117131825.GE3981@in.ibm.com> <20051117132004.GF3981@in.ibm.com> <20051117132138.GG3981@in.ibm.com> <20051117132315.GH3981@in.ibm.com> <20051117132437.GI3981@in.ibm.com> <20051117132557.GJ3981@in.ibm.com> <20051117132659.GK3981@in.ibm.com> <20051117132850.GL3981@in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1853 Lines: 52 On Fri, Nov 18, 2005 at 02:52:33PM -0700, Eric W. Biederman wrote: > > > diff -puN arch/x86_64/kernel/crash.c~x86_64-save-cpu-registers-upon-crash > > arch/x86_64/kernel/crash.c > > --- > > linux-2.6.15-rc1-1M-dynamic/arch/x86_64/kernel/crash.c~x86_64-save-cpu-registers-upon-crash > > > #ifdef CONFIG_SMP > > static atomic_t waiting_for_crash_ipi; > > > > @@ -38,6 +106,7 @@ static int crash_nmi_callback(struct pt_ > > return 1; > > local_irq_disable(); > > > > + crash_save_this_cpu(regs, cpu); > > disable_local_APIC(); > > atomic_dec(&waiting_for_crash_ipi); > > /* Assume hlt works */ > > @@ -113,4 +182,5 @@ void machine_crash_shutdown(struct pt_re > > disable_IO_APIC(); > > #endif > > > > + crash_save_self(regs); > > } > > Where did this disable_local_APIC and disable_IO_APIC on x86_64 come > from? I know we had it on x86 but that was supposed to be a stop gap > until we have the real fix. Now I know it needs a little more > debugging but the real fix has been written. Putting it there on > x86_64 makes the code less reliable and it allows things to start > depending on it. > Hi Eric, Initially we had written the patch without disable_local_APIC and disable_IO_APIC only. But realized later that fix provided by you to move apic initialization in init_IRQ has not been merged yet. Like i386, here also this is a stop gap solution only till your patch is merged. After that we shall drop this code. I understand that it is less reliable but at least it provides us a base to move forward and test kdump on x86_64 and address the other issues. 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/