From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx191.postini.com [74.125.245.191]) by kanga.kvack.org (Postfix) with SMTP id 63BC06B0068 for ; Wed, 12 Dec 2012 04:35:01 -0500 (EST) Message-ID: <50C84F8E.5030805@cn.fujitsu.com> Date: Wed, 12 Dec 2012 17:34:06 +0800 From: Tang Chen MIME-Version: 1.0 Subject: Re: [PATCH v3 4/5][RESEND] page_alloc: Make movablecore_map has higher priority References: <1355193207-21797-5-git-send-email-tangchen@cn.fujitsu.com> <1355201817-27230-1-git-send-email-tangchen@cn.fujitsu.com> <1355276008.1433.1.camel@kernel.cn.ibm.com> In-Reply-To: <1355276008.1433.1.camel@kernel.cn.ibm.com> Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8; format=flowed Sender: owner-linux-mm@kvack.org List-ID: To: Simon Jeons Cc: jiang.liu@huawei.com, wujianguo@huawei.com, hpa@zytor.com, akpm@linux-foundation.org, wency@cn.fujitsu.com, laijs@cn.fujitsu.com, linfeng@cn.fujitsu.com, yinghai@kernel.org, isimatu.yasuaki@jp.fujitsu.com, rob@landley.net, kosaki.motohiro@jp.fujitsu.com, minchan.kim@gmail.com, mgorman@suse.de, rientjes@google.com, rusty@rustcorp.com.au, lliubbo@gmail.com, jaegeuk.hanse@gmail.com, tony.luck@intel.com, glommer@parallels.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-doc@vger.kernel.org Hi Simon, Thanks for reviewing. This logic is aimed at make movablecore_map coexist with kernelcore/movablecore. Please see below. :) On 12/12/2012 09:33 AM, Simon Jeons wrote: >> @@ -4839,9 +4839,17 @@ static void __init find_zone_movable_pfns_for_nodes(void) >> required_kernelcore = max(required_kernelcore, corepages); >> } >> >> - /* If kernelcore was not specified, there is no ZONE_MOVABLE */ >> - if (!required_kernelcore) >> + /* >> + * If neither kernelcore/movablecore nor movablecore_map is specified, >> + * there is no ZONE_MOVABLE. But if movablecore_map is specified, the >> + * start pfn of ZONE_MOVABLE has been stored in zone_movable_limit[]. >> + */ >> + if (!required_kernelcore) { >> + if (movablecore_map.nr_map) >> + memcpy(zone_movable_pfn, zone_movable_limit, >> + sizeof(zone_movable_pfn)); If users didn't specified kernelcore option, then zone_movable_pfn[] and zone_movable_limit[] are all the same. We skip the logic. >> goto out; >> + } >> >> /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ >> usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; >> @@ -4871,10 +4879,24 @@ restart: >> for_each_mem_pfn_range(i, nid,&start_pfn,&end_pfn, NULL) { >> unsigned long size_pages; >> >> + /* >> + * Find more memory for kernelcore in >> + * [zone_movable_pfn[nid], zone_movable_limit[nid]). >> + */ >> start_pfn = max(start_pfn, zone_movable_pfn[nid]); >> if (start_pfn>= end_pfn) >> continue; >> > > Hi Chen, > >> + if (zone_movable_limit[nid]) { If users didn't give any limitation of ZONE_MOVABLE on node i, we could skip the logic too. >> + end_pfn = min(end_pfn, zone_movable_limit[nid]); In order to reuse the original kernelcore/movablecore logic, we keep end_pfn <= zone_movable_limit[nid]. We device [start_pfn, end_pfn) into two parts: [start_pfn, zone_movable_limit[nid]) and [zone_movable_limit[nid], end_pfn). We just remove the second part, and go on to the original logic. >> + /* No range left for kernelcore in this node */ >> + if (start_pfn>= end_pfn) { Since we re-evaluated end_pfn, if we have crossed the limitation, we should stop. >> + zone_movable_pfn[nid] = >> + zone_movable_limit[nid]; Here, we found the real limitation. That means, the lowest pfn of ZONE_MOVABLE is either zone_movable_limit[nid] or the value the original logic calculates out, which is below zone_movable_limit[nid]. >> + break; Then we break and go on to the next node. >> + } >> + } >> + > > Could you explain this part of codes? hard to understand. > >> /* Account for what is only usable for kernelcore */ >> if (start_pfn< usable_startpfn) { >> unsigned long kernel_pages; >> @@ -4934,12 +4956,12 @@ restart: >> if (usable_nodes&& required_kernelcore> usable_nodes) >> goto restart; >> >> +out: >> /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ >> for (nid = 0; nid< MAX_NUMNODES; nid++) >> zone_movable_pfn[nid] = >> roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); >> >> -out: >> /* restore the node_state */ >> node_states[N_HIGH_MEMORY] = saved_node_state; >> } > > > -- 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