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=-9.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 DA114C433E1 for ; Wed, 19 Aug 2020 12:41:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B2A3F206B5 for ; Wed, 19 Aug 2020 12:41:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728077AbgHSMlB (ORCPT ); Wed, 19 Aug 2020 08:41:01 -0400 Received: from mx2.suse.de ([195.135.220.15]:49970 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726794AbgHSMk7 (ORCPT ); Wed, 19 Aug 2020 08:40:59 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 16CEBAF92; Wed, 19 Aug 2020 12:41:24 +0000 (UTC) Date: Wed, 19 Aug 2020 14:40:57 +0200 From: Michal Hocko To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Wei Yang , Baoquan He , Pankaj Gupta , Oscar Salvador Subject: Re: [PATCH v1 04/11] mm/memory_hotplug: simplify offlining of pages in offline_pages() Message-ID: <20200819124057.GH5422@dhcp22.suse.cz> References: <20200819101157.12723-1-david@redhat.com> <20200819101157.12723-5-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200819101157.12723-5-david@redhat.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 19-08-20 12:11:50, David Hildenbrand wrote: > We make sure that we cannot have any memory holes right at the beginning > of offline_pages(). We no longer need walk_system_ram_range() and can > call __offline_isolated_pages() directly. > > offlined_pages always corresponds to nr_pages, so we can simplify that. I would probably fold this into the previous patch as they are dealing with the same thing. > Cc: Andrew Morton > Cc: Michal Hocko > Cc: Wei Yang > Cc: Baoquan He > Cc: Pankaj Gupta > Cc: Oscar Salvador > Signed-off-by: David Hildenbrand Acked-by: Michal Hocko > --- > mm/memory_hotplug.c | 28 ++++++++-------------------- > 1 file changed, 8 insertions(+), 20 deletions(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index f64478349148d..50aa5df696e9d 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1373,17 +1373,6 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) > return ret; > } > > -/* Mark all sections offline and remove all free pages from the buddy. */ > -static int > -offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages, > - void *data) > -{ > - unsigned long *offlined_pages = (unsigned long *)data; > - > - *offlined_pages += __offline_isolated_pages(start, start + nr_pages); > - return 0; > -} > - > static int __init cmdline_parse_movable_node(char *p) > { > movable_node_enabled = true; > @@ -1470,7 +1459,7 @@ static int count_system_ram_pages_cb(unsigned long start_pfn, > int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages) > { > const unsigned long end_pfn = start_pfn + nr_pages; > - unsigned long pfn, system_ram_pages = 0, offlined_pages = 0; > + unsigned long pfn, system_ram_pages = 0; > int ret, node, nr_isolate_pageblock; > unsigned long flags; > struct zone *zone; > @@ -1570,11 +1559,10 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages) > } > } while (test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE)); > > - /* Ok, all of our target is isolated. > - We cannot do rollback at this point. */ > - walk_system_ram_range(start_pfn, end_pfn - start_pfn, > - &offlined_pages, offline_isolated_pages_cb); > - pr_info("Offlined Pages %ld\n", offlined_pages); > + /* Mark all sections offline and remove free pages from the buddy. */ > + __offline_isolated_pages(start_pfn, end_pfn); > + pr_info("Offlined Pages %ld\n", nr_pages); > + > /* > * Onlining will reset pagetype flags and makes migrate type > * MOVABLE, so just need to decrease the number of isolated > @@ -1585,11 +1573,11 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages) > spin_unlock_irqrestore(&zone->lock, flags); > > /* removal success */ > - adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages); > - zone->present_pages -= offlined_pages; > + adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages); > + zone->present_pages -= nr_pages; > > pgdat_resize_lock(zone->zone_pgdat, &flags); > - zone->zone_pgdat->node_present_pages -= offlined_pages; > + zone->zone_pgdat->node_present_pages -= nr_pages; > pgdat_resize_unlock(zone->zone_pgdat, &flags); > > init_per_zone_wmark_min(); > -- > 2.26.2 > -- Michal Hocko SUSE Labs