From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VIur0-0005Rv-KV for kexec@lists.infradead.org; Mon, 09 Sep 2013 06:21:43 +0000 Received: from m2.gw.fujitsu.co.jp (unknown [10.0.50.72]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id A343E3EE0BC for ; Mon, 9 Sep 2013 15:21:16 +0900 (JST) Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 945D745DE6A for ; Mon, 9 Sep 2013 15:21:16 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id 61A2C45DE67 for ; Mon, 9 Sep 2013 15:21:16 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 462711DB8042 for ; Mon, 9 Sep 2013 15:21:16 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.240.81.134]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id EE5431DB802C for ; Mon, 9 Sep 2013 15:21:15 +0900 (JST) Message-ID: <522D681E.1030809@jp.fujitsu.com> Date: Mon, 09 Sep 2013 15:18:06 +0900 From: HATAYAMA Daisuke MIME-Version: 1.0 Subject: Re: [PATCH 2/2] x86, apic: Disable BSP if boot cpu is AP 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> <20130904061221.GA17791@x1.alien8.de> In-Reply-To: <20130904061221.GA17791@x1.alien8.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "kexec" Errors-To: kexec-bounces+dwmw2=twosheds.infradead.org@lists.infradead.org To: Borislav Petkov Cc: kexec@lists.infradead.org, linux-kernel@vger.kernel.org, vgoyal@redhat.com, ebiederm@xmission.com, akpm@linux-foundation.org, hpa@linux.intel.com, jingbai.ma@hp.com (2013/09/04 15:12), Borislav Petkov wrote: > 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. > Yes, that's the point this patch series misses. I'll describe the explanation in Documentation/kexec/kexec.txt and point it in the comment of boot-up code. -- Thanks. HATAYAMA, Daisuke _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec