From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.skyhub.de ([2a01:4f8:120:8448::d00d]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VH6KI-00041K-6O for kexec@lists.infradead.org; Wed, 04 Sep 2013 06:12:27 +0000 Date: Wed, 4 Sep 2013 08:12:22 +0200 From: Borislav Petkov Subject: Re: [PATCH 2/2] x86, apic: Disable BSP if boot cpu is AP Message-ID: <20130904061221.GA17791@x1.alien8.de> References: <20130829092458.5476.10277.stgit@localhost6.localdomain6> <20130829092804.5476.95588.stgit@localhost6.localdomain6> <20130831052252.GC12617@x1.alien8.de> <5223F8DB.3040506@jp.fujitsu.com> <20130902071318.GA3406@x1.alien8.de> <52245D94.5050702@jp.fujitsu.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <52245D94.5050702@jp.fujitsu.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org To: HATAYAMA Daisuke Cc: jingbai.ma@hp.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, ebiederm@xmission.com, akpm@linux-foundation.org, hpa@linux.intel.com, vgoyal@redhat.com On Mon, Sep 02, 2013 at 06:42:44PM +0900, HATAYAMA Daisuke wrote: > The reason why I don't lookup BSP flag in MSR is that it's impossible. > To read MSR of some CPU, we need to use rdmsr instruction on the CPU. > However, in case of this issue, the BSP is halting or running in > the kdump 1st kernel. Yes, and on the AP, that flag would be cleared which makes it not a BSP. > A whole explanation is written in the patch description. Those tend to get lost in git history when a bunch of whitespace jerk offs appear ontop. So a nicely written comment in the code could be very helpful. Thanks. -- Regards/Gruss, Boris. _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec