From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f199.google.com (mail-pf0-f199.google.com [209.85.192.199]) by kanga.kvack.org (Postfix) with ESMTP id 6B8A66B0253 for ; Wed, 3 Aug 2016 14:17:45 -0400 (EDT) Received: by mail-pf0-f199.google.com with SMTP id w128so407894052pfd.3 for ; Wed, 03 Aug 2016 11:17:45 -0700 (PDT) Received: from mga14.intel.com (mga14.intel.com. [192.55.52.115]) by mx.google.com with ESMTP id r68si9921715pfb.169.2016.08.03.11.17.44 for ; Wed, 03 Aug 2016 11:17:44 -0700 (PDT) Subject: Re: [PATCH 1/2] mm: Allow disabling deferred struct page initialisation References: <1470143947-24443-1-git-send-email-srikar@linux.vnet.ibm.com> <1470143947-24443-2-git-send-email-srikar@linux.vnet.ibm.com> <57A0E1D1.8020608@intel.com> <20160803063808.GI6310@linux.vnet.ibm.com> From: Dave Hansen Message-ID: <57A23547.1070207@intel.com> Date: Wed, 3 Aug 2016 11:17:43 -0700 MIME-Version: 1.0 In-Reply-To: <20160803063808.GI6310@linux.vnet.ibm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Srikar Dronamraju Cc: linux-mm@kvack.org, Mel Gorman , Vlastimil Babka , Michal Hocko , Andrew Morton , Michael Ellerman , linuxppc-dev@lists.ozlabs.org, mahesh@linux.vnet.ibm.com, hbathini@linux.vnet.ibm.com On 08/02/2016 11:38 PM, Srikar Dronamraju wrote: > * Dave Hansen [2016-08-02 11:09:21]: >> On 08/02/2016 06:19 AM, Srikar Dronamraju wrote: >>> Kernels compiled with CONFIG_DEFERRED_STRUCT_PAGE_INIT will initialise >>> only certain size memory per node. The certain size takes into account >>> the dentry and inode cache sizes. However such a kernel when booting a >>> secondary kernel will not be able to allocate the required amount of >>> memory to suffice for the dentry and inode caches. This results in >>> crashes like the below on large systems such as 32 TB systems. >> >> What's a "secondary kernel"? >> > I mean the kernel thats booted to collect the crash, On fadump, the > first kernel acts as the secondary kernel i.e the same kernel is booted > to collect the crash. OK, but I'm still not seeing what the problem is. You've said that it crashes and that it crashes during inode/dentry cache allocation. But, *why* does the same kernel image crash in when it is used as a "secondary kernel"? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org