From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by canuck.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1QoK7P-0000QN-Qk for kexec@lists.infradead.org; Tue, 02 Aug 2011 18:55:08 +0000 Date: Tue, 2 Aug 2011 14:55:01 -0400 From: Vivek Goyal Subject: Re: [patch v2 03/10] kdump: Add size to elfcorehdr kernel parameter Message-ID: <20110802185501.GG6399@redhat.com> References: <20110727125504.491183728@linux.vnet.ibm.com> <20110727125807.853426542@linux.vnet.ibm.com> <20110801203607.GI3805@redhat.com> <1312276087.4881.24.camel@br98xy6r> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1312276087.4881.24.camel@br98xy6r> 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=twosheds.infradead.org@lists.infradead.org To: Michael Holzheu Cc: oomichi@mxs.nes.nec.co.jp, linux-s390@vger.kernel.org, mahesh@linux.vnet.ibm.com, heiko.carstens@de.ibm.com, linux-kernel@vger.kernel.org, hbabu@us.ibm.com, horms@verge.net.au, ebiederm@xmission.com, schwidefsky@de.ibm.com, kexec@lists.infradead.org On Tue, Aug 02, 2011 at 11:08:07AM +0200, Michael Holzheu wrote: > Hello Vivek, > > #On Mon, 2011-08-01 at 16:36 -0400, Vivek Goyal wrote: > > On Wed, Jul 27, 2011 at 02:55:07PM +0200, Michael Holzheu wrote: > > > From: Michael Holzheu > > > > > > Currently only the address of the pre-allocated ELF header is passed with > > > the elfcorehdr= kernel parameter. In order to reserve memory for the header > > > in the 2nd kernel also the size is required. To pass the size with this > > > patch the syntax of the kernel parameter is extended as follows: > > > > > > elfcorehdr=[size[KMG]@]offset[KMG] > > > > > > This change is backward compatible because elfcorehdr=size is still allowed. > > > > Generally vmcore parses elfcorehdr to figure out the sizes. kexec-tools > > knows about it and relevant memory is excluded from second kernel's map > > with the help of memmap= command line option. > > > > Can you please mention that this is only s390 specific requirement as > > there are no memmap= equivalent options and somehow dump tools wants > > to know how big the elf header size is? > > I updated the description: > > Currently only the address of the pre-allocated ELF header is passed with > the elfcorehdr= kernel parameter. In order to reserve memory for the header > in the 2nd kernel also the size is required. Current kdump architecture > backends use different methods to do that, e.g. x86 uses the memmap= kernel > parameter. On s390 there is no easy way to transfer this information. > Therefore the elfcorehdr kernel parameter is extended to also pass the size. > This now can also be used as standard mechanism by all future kdump > architecture backends. > > The syntax of the kernel parameter is extended as follows: > > elfcorehdr=[size[KMG]@]offset[KMG] > > This change is backward compatible because elfcorehdr=size is still allowed. > > Ok? Yes, this one looks ok. Thanks Vivek _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec