From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [patch v2 03/10] kdump: Add size to elfcorehdr kernel parameter From: Michael Holzheu Reply-To: holzheu@linux.vnet.ibm.com In-Reply-To: <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> <20110802185501.GG6399@redhat.com> Content-Type: text/plain; charset="UTF-8" Date: Wed, 03 Aug 2011 12:40:44 +0200 Message-ID: <1312368044.3783.39.camel@br98xy6r> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Vivek Goyal Cc: ebiederm@xmission.com, mahesh@linux.vnet.ibm.com, hbabu@us.ibm.com, oomichi@mxs.nes.nec.co.jp, horms@verge.net.au, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org List-ID: Hello Vivek, On Tue, 2011-08-02 at 14:55 -0400, Vivek Goyal wrote: > On Tue, Aug 02, 2011 at 11:08:07AM +0200, Michael Holzheu wrote: > > Hello Vivek, > > > > > 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. With that description change: Do I get an "Acked-by" for this patch from you? Michael