From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from out3.smtp.messagingengine.com ([66.111.4.27]) by bombadil.infradead.org with esmtp (Exim 4.68 #1 (Red Hat Linux)) id 1Ksanb-0006i2-K8 for kexec@lists.infradead.org; Wed, 22 Oct 2008 10:18:43 +0000 Message-Id: <1224670721.25843.1280616145@webmail.messagingengine.com> From: "Alexander van Heukelum" Content-Disposition: inline MIME-Version: 1.0 References: <20081017210013.GD23591@hmsreliant.think-freely.org> <20081020121339.GE10594@elte.hu> <20081020134211.GA15574@hmsreliant.think-freely.org> <20081020150731.GA25999@mailshack.com> <20081020150834.GA26018@mailshack.com> <20081021144505.GA25750@hmsreliant.think-freely.org> Subject: Re: [PATCH] x86: make oops_begin and oops_end equal In-Reply-To: <20081021144505.GA25750@hmsreliant.think-freely.org> Date: Wed, 22 Oct 2008 12:18:41 +0200 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-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Neil Horman , Alexander van Heukelum Cc: Andrew Morton , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, hbabu@us.ibm.com, mingo@redhat.com, "Eric W. Biederman" , "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner , vgoyal@redhat.com On Tue, 21 Oct 2008 10:45:05 -0400, "Neil Horman" said: > On Mon, Oct 20, 2008 at 05:08:34PM +0200, Alexander van Heukelum wrote: > > Mostly use the x86_64 version of oops_begin() and oops_end() on > > i386 too. Changes to the original x86_64 version: > > > Hey, doing a sight review this am here. Didn't find anything major, but > I did > find a few little nits. comments inlie Hi Neil, Thanks for the review. I've sent a redone patch series just a moment ago, based on your comments. There was also another problem with these two patches: oops_end(flags, regs, signr) had special behaviour for regs=NULL that I did not consider before. The series has grown due to this issue... >> [...] > Hmm. I think this creates the same case that I just fixed in my initial > post. If we start using oops_end with this here, it may be possible to call > crash_kexec with the console_sem held. If that happens, we deadlock. I > think you should be able to move this clause up above the bust_spinlocks(0) > without any issue, and that would take care of that Indeed. The new series does exactly that. >> [...] > This undoes my previous patch. I realize your second patch fixes it > properly so the ordering is correct when oops_begin and oops_end are used, but if you > could rediff so this isn't here, I'd appreciate it. If these patches are > committed separately, you'll avoid having the tree in a state where that deadlock > can reoccur (even if it is just for one commit) Yeah, I quickly rediffed the patches I already had. The new series leaves it as is until die_nmi is replaced by the oops_begin/oops_end version. >> [...] > If you're going to add the crash_kexec here (which looking at the call > sites, makes sense to me), you should likely remove it from the critical section > of die and die_nmi, just to avoid the redundancy. Same issue as the 32 bit > version above applies, this needs to happen before you call bust_spinlocks(0). Indeed. > Fix those issues, and the rest looks good to me. I think I've done that ;). Thanks, Greetings, Alexander (I will probably not be able to respond to e-mail until after the weekend) -- Alexander van Heukelum heukelum@fastmail.fm -- http://www.fastmail.fm - mmm... Fastmail... _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec