From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f50.google.com (mail-pa0-f50.google.com [209.85.220.50]) by kanga.kvack.org (Postfix) with ESMTP id 522A66B0253 for ; Tue, 13 Oct 2015 23:47:56 -0400 (EDT) Received: by padcn9 with SMTP id cn9so9721857pad.2 for ; Tue, 13 Oct 2015 20:47:56 -0700 (PDT) Received: from szxga03-in.huawei.com (szxga03-in.huawei.com. [119.145.14.66]) by mx.google.com with ESMTP id u2si9860568pbs.213.2015.10.13.20.47.54 for ; Tue, 13 Oct 2015 20:47:55 -0700 (PDT) Message-ID: <561DCBF9.4050000@huawei.com> Date: Wed, 14 Oct 2015 11:28:57 +0800 From: Xishi Qiu MIME-Version: 1.0 Subject: Re: [PATCH] mm: skip if required_kernelcore is larger than totalpages References: <5615D311.5030908@huawei.com> <5617e00e.0c5b8c0a.2d0dd.3faa@mx.google.com> <561B0ECD.5000507@huawei.com> <561DC30C.70909@cn.fujitsu.com> In-Reply-To: <561DC30C.70909@cn.fujitsu.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Tang Chen Cc: Yasuaki Ishimatsu , Andrew Morton , Yasuaki Ishimatsu , Mel Gorman , David Rientjes , zhongjiang@huawei.com, Linux MM , LKML On 2015/10/14 10:50, Tang Chen wrote: > Hi, Qiu > > The patch seems OK to me. Only one little concern below. > > On 10/12/2015 09:37 AM, Xishi Qiu wrote: >> On 2015/10/9 23:41, Yasuaki Ishimatsu wrote: >> >>> On Thu, 8 Oct 2015 10:21:05 +0800 >>> Xishi Qiu wrote: >>> >>>> If kernelcore was not specified, or the kernelcore size is zero >>>> (required_movablecore >= totalpages), or the kernelcore size is larger >>> Why does required_movablecore become larger than totalpages, when the >>> kernelcore size is zero? I read the code but I could not find that you >>> mention. >>> >> If user only set boot option movablecore, and the value is larger than >> totalpages, the calculation of kernelcore is zero, but we can't fill >> the zone only with kernelcore, so skip it. >> >> I have send a patch before this patch. >> "fix overflow in find_zone_movable_pfns_for_nodes()" >> ... >> required_movablecore = >> roundup(required_movablecore, MAX_ORDER_NR_PAGES); >> + required_movablecore = min(totalpages, required_movablecore); >> corepages = totalpages - required_movablecore; >> ... > > > So if required_movablecore >= totalpages, there won't be any ZONE_MOVABLE. > How about add a warning or debug info to tell the user he has specified a > too large movablecore, and it is ignored ? > > Thanks. Yes, but I don't think is is necessary, user should know the total memory before he set the boot option. Thanks, Xishi Qiu -- 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