From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B98ABC43441 for ; Fri, 16 Nov 2018 10:24:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7FCA32086C for ; Fri, 16 Nov 2018 10:24:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7FCA32086C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389420AbeKPUft (ORCPT ); Fri, 16 Nov 2018 15:35:49 -0500 Received: from mx2.suse.de ([195.135.220.15]:46422 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727446AbeKPUft (ORCPT ); Fri, 16 Nov 2018 15:35:49 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 39DBDAF3A; Fri, 16 Nov 2018 10:24:06 +0000 (UTC) Date: Fri, 16 Nov 2018 11:24:05 +0100 From: Michal Hocko To: Wei Yang Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Rafael J. Wysocki" Subject: Re: [PATCH] mm: use managed_zone() for more exact check in zone iteration Message-ID: <20181116102405.GF14706@dhcp22.suse.cz> References: <20181114235040.36180-1-richard.weiyang@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181114235040.36180-1-richard.weiyang@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 15-11-18 07:50:40, Wei Yang wrote: [...] > @@ -1193,8 +1196,8 @@ static unsigned int count_free_highmem_pages(void) > struct zone *zone; > unsigned int cnt = 0; > > - for_each_populated_zone(zone) > - if (is_highmem(zone)) > + for_each_zone(zone) > + if (populated_zone(zone) && is_highmem(zone)) > cnt += zone_page_state(zone, NR_FREE_PAGES); this should be for_each_managed_zone because we only care about highmem zones which have pages in the allocator (NR_FREE_PAGES). > > return cnt; > @@ -1239,10 +1242,10 @@ static unsigned int count_highmem_pages(void) > struct zone *zone; > unsigned int n = 0; > > - for_each_populated_zone(zone) { > + for_each_zone(zone) { > unsigned long pfn, max_zone_pfn; > > - if (!is_highmem(zone)) > + if (!populated_zone(zone) || !is_highmem(zone)) > continue; > > mark_free_pages(zone); I am not familiar with this code much but I strongly suspect that we do want for_each_managed_zone here because saveable_highmem_page skips over all reserved pages which rules out the bootmem. But this should be double checked with Rafael (Cc-ed). Rafael, does this loop care about pages which are not managed by the page allocator? > @@ -1305,8 +1308,8 @@ static unsigned int count_data_pages(void) > unsigned long pfn, max_zone_pfn; > unsigned int n = 0; > > - for_each_populated_zone(zone) { > - if (is_highmem(zone)) > + for_each_zone(zone) { > + if (!populated_zone(zone) || is_highmem(zone)) > continue; > > mark_free_pages(zone); > @@ -1399,9 +1402,12 @@ static void copy_data_pages(struct memory_bitmap *copy_bm, > struct zone *zone; > unsigned long pfn; > > - for_each_populated_zone(zone) { > + for_each_zone(zone) { > unsigned long max_zone_pfn; > > + if (!populated_zone(zone)) > + continue; > + > mark_free_pages(zone); > max_zone_pfn = zone_end_pfn(zone); > for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) > @@ -1717,7 +1723,10 @@ int hibernate_preallocate_memory(void) > saveable += save_highmem; > highmem = save_highmem; > size = 0; > - for_each_populated_zone(zone) { > + for_each_zone(zone) { > + if (!populated_zone(zone)) > + continue; > + > size += snapshot_additional_pages(zone); > if (is_highmem(zone)) > highmem += zone_page_state(zone, NR_FREE_PAGES); ditto for the above. > @@ -1863,8 +1872,8 @@ static int enough_free_mem(unsigned int nr_pages, unsigned int nr_highmem) > struct zone *zone; > unsigned int free = alloc_normal; > > - for_each_populated_zone(zone) > - if (!is_highmem(zone)) > + for_each_zone(zone) > + if (populated_zone(zone) && !is_highmem(zone)) > free += zone_page_state(zone, NR_FREE_PAGES); > > nr_pages += count_pages_for_highmem(nr_highmem); This one should be for_each_managed_zone (NR_FREE_PAGES) The rest looks good to me. -- Michal Hocko SUSE Labs