From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mga02.intel.com ([134.134.136.20]) by bombadil.infradead.org with esmtp (Exim 4.68 #1 (Red Hat Linux)) id 1KSLlR-0004tW-Jm for kexec@lists.infradead.org; Mon, 11 Aug 2008 01:00:02 +0000 Subject: Re: [PATCH -v2 6/8] kexec jump: fix for lockdep From: Huang Ying In-Reply-To: <1218190426.8625.71.camel@twins> References: <1218178365.22039.79.camel@caritas-dev.intel.com> <1218190426.8625.71.camel@twins> Date: Mon, 11 Aug 2008 08:59:56 +0800 Message-Id: <1218416396.30464.9.camel@caritas-dev.intel.com> Mime-Version: 1.0 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: Peter Zijlstra Cc: nigel@nigel.suspend2.net, Kexec Mailing List , linux-kernel@vger.kernel.org, "Rafael J. Wysocki" , "Eric W. Biederman" , Pavel Machek , Andrew Morton , Linus Torvalds , mingo@elte.hu, Vivek Goyal On Fri, 2008-08-08 at 12:13 +0200, Peter Zijlstra wrote: > On Fri, 2008-08-08 at 14:52 +0800, Huang Ying wrote: > > Replace local_irq_disable() with raw_local_irq_disable() to prevent > > lockdep complain. > Uhhm, please provide more information - just using raw_* to silence > lockdep is generally the wrong thing to do. In traditional kexec, the new kernel will replace current one, so the irq is simply disabled. But now jumping back from kexeced kernel is supported, so the irq should be enabled again. The code sequence of irq during kexec jump is as follow: local_irq_disable(); /* in kernel_kexec() */ local_irq_disable(); /* in machine_kexec() */ local_irq_enable(); /* in kernel_kexec() */ The disable and enable is not match. Maybe another method is to use local_irq_save(), local_irq_restore() pair in machine_kexec(), so the disable and enable is matched. Best Regrards, Huang Ying _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec