From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.linuxfoundation.org ([140.211.169.12]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UI2Jt-0001yF-4I for kexec@lists.infradead.org; Tue, 19 Mar 2013 19:35:37 +0000 Date: Tue, 19 Mar 2013 12:35:31 -0700 From: Andrew Morton Subject: Re: [PATCH v3 07/21] vmcore, procfs: introduce a flag to distinguish objects copied in 2nd kernel Message-Id: <20130319123531.9777a366ff0e1611727405cd@linux-foundation.org> In-Reply-To: <20130316040126.15064.67305.stgit@localhost6.localdomain6> References: <20130316040003.15064.62308.stgit@localhost6.localdomain6> <20130316040126.15064.67305.stgit@localhost6.localdomain6> 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" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: HATAYAMA Daisuke Cc: kexec@lists.infradead.org, heiko.carstens@de.ibm.com, linux-kernel@vger.kernel.org, lisa.mitchell@hp.com, kumagai-atsushi@mxc.nes.nec.co.jp, ebiederm@xmission.com, zhangyanfei@cn.fujitsu.com, cpw@sgi.com, vgoyal@redhat.com On Sat, 16 Mar 2013 13:01:26 +0900 HATAYAMA Daisuke wrote: > The part of dump target memory is copied into the 2nd kernel if it > doesn't satisfy mmap()'s page-size boundary requirement. To > distinguish such copied object from usual old memory, a flag > MEM_TYPE_CURRENT_KERNEL is introduced. If this flag is set, the object > is considered being copied into buffer on the 2nd kernel. > I don't understand this description at all :( Perhaps we can have a lengthier version which expands on the concepts a bit further? > --- a/include/linux/proc_fs.h > +++ b/include/linux/proc_fs.h > @@ -97,11 +97,17 @@ struct kcore_list { > int type; > }; > > +#define MEM_TYPE_CURRENT_KERNEL 0x1 A comment describing this would be useful. > struct vmcore { > struct list_head list; > - unsigned long long paddr; > + union { > + unsigned long long paddr; > + char *buf; > + }; This change wasn't described in the changelog? > unsigned long long size; > loff_t offset; > + unsigned int flag; Presumably this is the place where we put MEM_TYPE_CURRENT_KERNEL? That's unobvious from reading the code. Add the text "vmcore.flag fields:" above the MEM_TYPE_CURRENT_KERNEL definition. > }; > > #ifdef CONFIG_PROC_FS _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec