From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3s5JMT3RFjzDqPn for ; Fri, 5 Aug 2016 17:28:53 +1000 (AEST) Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u757PZIx128006 for ; Fri, 5 Aug 2016 03:28:51 -0400 Received: from e23smtp03.au.ibm.com (e23smtp03.au.ibm.com [202.81.31.145]) by mx0a-001b2d01.pphosted.com with ESMTP id 24kkajhh4f-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Fri, 05 Aug 2016 03:28:51 -0400 Received: from localhost by e23smtp03.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 5 Aug 2016 17:28:48 +1000 Received: from d23relay09.au.ibm.com (d23relay09.au.ibm.com [9.185.63.181]) by d23dlp03.au.ibm.com (Postfix) with ESMTP id 09DF2357805D for ; Fri, 5 Aug 2016 17:28:46 +1000 (EST) Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay09.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u757SjA226673326 for ; Fri, 5 Aug 2016 17:28:45 +1000 Received: from d23av04.au.ibm.com (localhost [127.0.0.1]) by d23av04.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u757ShSg026235 for ; Fri, 5 Aug 2016 17:28:45 +1000 Date: Fri, 5 Aug 2016 12:58:38 +0530 From: Srikar Dronamraju To: Michael Ellerman Cc: linux-mm@kvack.org, Mel Gorman , Vlastimil Babka , Michal Hocko , Andrew Morton , linuxppc-dev@lists.ozlabs.org, Mahesh Salgaonkar , Hari Bathini , Dave Hansen , Balbir Singh Subject: Re: [PATCH] fadump: Register the memory reserved by fadump Reply-To: Srikar Dronamraju References: <1470318165-2521-1-git-send-email-srikar@linux.vnet.ibm.com> <87mvkritii.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 In-Reply-To: <87mvkritii.fsf@concordia.ellerman.id.au> Message-Id: <20160805072838.GF11268@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , * Michael Ellerman [2016-08-05 17:07:01]: > Srikar Dronamraju writes: > > > Fadump kernel reserves large chunks of memory even before the pages are > > initialized. This could mean memory that corresponds to several nodes might > > fall in memblock reserved regions. > > > ... > > Register the memory reserved by fadump, so that the cache sizes are > > calculated based on the free memory (i.e Total memory - reserved > > memory). > > The memory is reserved, with memblock_reserve(). Why is that not sufficient? > > cheers > Because at page initialization time, the kernel doesnt know how many pages are reserved. One way to do that would be to walk through the different memory reserved blocks and calculate the size. But Mel feels thats an overhead (from his reply to the other thread) esp for just one use case. -- Thanks and Regards Srikar Dronamraju