Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161269AbVKRVxL (ORCPT ); Fri, 18 Nov 2005 16:53:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161270AbVKRVxK (ORCPT ); Fri, 18 Nov 2005 16:53:10 -0500 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:64914 "EHLO ebiederm.dsl.xmission.com") by vger.kernel.org with ESMTP id S1161269AbVKRVxJ (ORCPT ); Fri, 18 Nov 2005 16:53:09 -0500 To: vgoyal@in.ibm.com 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 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> From: ebiederm@xmission.com (Eric W. Biederman) Date: Fri, 18 Nov 2005 14:52:33 -0700 In-Reply-To: <20051117132850.GL3981@in.ibm.com> (Vivek Goyal's message of "Thu, 17 Nov 2005 18:58:50 +0530") Message-ID: User-Agent: Gnus/5.1007 (Gnus v5.10.7) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1487 Lines: 44 > 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. Please don't saving of the apics to x86_64 propagate this to x86_64. The rest of the patch looks fine fairly sane, although from a purely paranoid perspective I can see a few things I would need to look at more to be certain they are safe. Eric - 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/