From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gUUEy-0002Ht-FT for kexec@lists.infradead.org; Wed, 05 Dec 2018 10:17:13 +0000 Date: Wed, 5 Dec 2018 18:16:53 +0800 From: Dave Young Subject: Re: [PATCH 1/2 v2] kdump: add the vmcoreinfo documentation Message-ID: <20181205101653.GA6940@dhcp-128-65.nay.redhat.com> References: <20181202030839.29945-1-lijiang@redhat.com> <20181202030839.29945-2-lijiang@redhat.com> <20181203150809.GA4794@zn.tnic> <779dbae7-f6e2-e9e4-bdd0-0a9e6ec62487@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <779dbae7-f6e2-e9e4-bdd0-0a9e6ec62487@redhat.com> 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: lijiang Cc: Kazuhito Hagio , linux-doc@vger.kernel.org, bhe@redhat.com, Jonathan Corbet , x86@kernel.org, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, mingo@redhat.com, Borislav Petkov , tglx@linutronix.de, akpm@linux-foundation.org > >> +init_uts_ns > >> +=========== > >> +This is the UTS namespace, which is used to isolate two specific elements > >> +of the system that relate to the uname system call. The UTS namespace is > >> +named after the data structure used to store information returned by the > >> +uname system call. > > > > Those non-obvious exports should also have a short explanation why > > they're part of VMCOREINFO. > > > >> + > >> +node_online_map > >> +=============== > >> +It is a macro definition, actually it is an arrary node_states[N_ONLINE], > >> +and it represents the set of online node in a system, one bit position > >> +per node number. > > > > Ditto. > > > > So yeah, people can find out what those things are but I think it is > > more important to state here *why* they're part of VMCOREINFO and how > > they're used and why they're exported. > > > > This is a good question. > > For these two *why*, it should be easy to understand. Because user-space tools > need to know basic information, such as the symbol values, field offset, structure > size, etc. Otherwise, these tools won't know how to analyze the memory of the crash > kernel. > > For the second question 'how they are used', we can get the answer from user-space > tools, such as makedumpfile, crash tools. Therefore, it may not need to explain any > more in kernel document. On the other hand, if we must put these contents into kernel > document, i have to say, that would be a hard task. It should be a good chance to learn how makedumpfile works :), Maybe it is hard to get *all* of them, but it would be good to dig and find the thing you can find then explain it. And leave those *unknown* part as FIXME or TODO, people can add description later. Added Kazu in cc as well.. Thanks Dave _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec