From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f72.google.com (mail-lf0-f72.google.com [209.85.215.72]) by kanga.kvack.org (Postfix) with ESMTP id CD0516B0253 for ; Thu, 4 Aug 2016 01:10:46 -0400 (EDT) Received: by mail-lf0-f72.google.com with SMTP id p85so126110576lfg.3 for ; Wed, 03 Aug 2016 22:10:46 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com. [148.163.158.5]) by mx.google.com with ESMTPS id f9si2078304wmg.96.2016.08.03.22.10.44 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 03 Aug 2016 22:10:45 -0700 (PDT) Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u7458vIB089609 for ; Thu, 4 Aug 2016 01:10:43 -0400 Received: from e23smtp03.au.ibm.com (e23smtp03.au.ibm.com [202.81.31.145]) by mx0a-001b2d01.pphosted.com with ESMTP id 24kkak15fx-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Thu, 04 Aug 2016 01:10:43 -0400 Received: from localhost by e23smtp03.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 4 Aug 2016 15:10:40 +1000 Received: from d23relay09.au.ibm.com (d23relay09.au.ibm.com [9.185.63.181]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id 727462BB0059 for ; Thu, 4 Aug 2016 15:10:38 +1000 (EST) Received: from d23av02.au.ibm.com (d23av02.au.ibm.com [9.190.235.138]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u745AcJv29753576 for ; Thu, 4 Aug 2016 15:10:38 +1000 Received: from d23av02.au.ibm.com (localhost [127.0.0.1]) by d23av02.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u745AbUF010327 for ; Thu, 4 Aug 2016 15:10:38 +1000 Date: Thu, 4 Aug 2016 10:40:35 +0530 From: Srikar Dronamraju Subject: Re: [PATCH 2/2] fadump: Disable deferred page struct initialisation Reply-To: Srikar Dronamraju References: <1470143947-24443-1-git-send-email-srikar@linux.vnet.ibm.com> <1470143947-24443-3-git-send-email-srikar@linux.vnet.ibm.com> <1470201642.5034.3.camel@gmail.com> <20160803063538.GH6310@linux.vnet.ibm.com> <57A248A1.40807@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <57A248A1.40807@intel.com> Message-Id: <20160804051035.GA11268@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Dave Hansen Cc: Balbir Singh , linux-mm@kvack.org, Mel Gorman , Vlastimil Babka , Michal Hocko , Andrew Morton , Michael Ellerman , mahesh@linux.vnet.ibm.com * Dave Hansen [2016-08-03 12:40:17]: > On 08/02/2016 11:35 PM, Srikar Dronamraju wrote: > > On a regular kernel with CONFIG_FADUMP and fadump configured, 5% of the > > total memory is reserved for booting the kernel on crash. On crash, > > fadump kernel reserves the 95% memory and boots into the 5% memory that > > was reserved for it. It then parses the reserved 95% memory to collect > > the dump. > > > > The problem is not about the amount of memory thats reserved for fadump > > kernel. Even if we increase/decrease, we will still end up with the same > > issue. > > Oh, and the dentry/inode caches are sized based on 100% of memory, not > the 5% that's left after the fadump reservation? Yes, the dentry/inode caches are sized based on the 100% memory. > > Is the deferred initialization kicked in progress at the time we do the > dentry/inode allocations? Can waiting a bit let the allocation succeed? > Right now deferred initialisation kicks in after dentry/inode allocations. Can we defer the cache allocations till deferred initialisation? I dont know. But if we can that could potentially solve the problem. May be Mel or somebody might be able answer if we can defer dentry/inode cache allocations till deferred initialisation kicks in. The other idea is to detect nodes whose memory is reserved and allocate extra memory from the nodes where memory is not yet reserved. -- Thanks and Regards Srikar Dronamraju -- 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