From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Xn65c-0004gC-B6 for kexec@lists.infradead.org; Sat, 08 Nov 2014 13:30:05 +0000 Message-ID: <545E1AB1.9030001@redhat.com> Date: Sat, 08 Nov 2014 08:29:21 -0500 From: Prarit Bhargava MIME-Version: 1.0 Subject: Re: [PATCH v8] kernel, add panic_on_warn References: <1415187736-16242-1-git-send-email-prarit@redhat.com> <545B733C.6080903@redhat.com> <20141106220731.GA13590@redhat.com> <545CA765.8010403@redhat.com> In-Reply-To: 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=infradead.org@lists.infradead.org To: David Rientjes Cc: Andi Kleen , Jonathan Corbet , jbaron@akamai.com, kexec@lists.infradead.org, Rusty Russell , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Fabian Frederick , isimatu.yasuaki@jp.fujitsu.com, "H. Peter Anvin" , Masami Hiramatsu , Andrew Morton , linux-api@vger.kernel.org, Vivek Goyal On 11/07/2014 04:09 PM, David Rientjes wrote: > On Fri, 7 Nov 2014, Prarit Bhargava wrote: > >> There very much is. Consider a thread that hits a WARN() and then panics. Then >> somewhere in the panic code the thread hits another WARN() ... and then panics >> again. Previously this would have caused the system to "finish" panick'ing. >> Now it makes the system hang. >> > > Then we're back to square one which is what is obviously the intent of > your patch and the comment that goes along with it: My original reply pointed out that the comment was wrong. we want to clear > panic_on_warn once and not allow multiple panic(). On _this_ thread. The multiple panic across threads cannot occur. So why not just add > the necessary synchronization to make sure that happens when WARN() > happens on two cpus simultaneously? See above. P. > _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec