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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id BAC51C433EF for ; Thu, 27 Jan 2022 08:28:23 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 131206B0071; Thu, 27 Jan 2022 03:28:23 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0E1346B0072; Thu, 27 Jan 2022 03:28:23 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 01DFB6B0073; Thu, 27 Jan 2022 03:28:22 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0221.hostedemail.com [216.40.44.221]) by kanga.kvack.org (Postfix) with ESMTP id E7CED6B0071 for ; Thu, 27 Jan 2022 03:28:22 -0500 (EST) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 79AFD181E48F2 for ; Thu, 27 Jan 2022 08:28:22 +0000 (UTC) X-FDA: 79075390044.29.52FB294 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by imf01.hostedemail.com (Postfix) with ESMTP id 0437B40002 for ; Thu, 27 Jan 2022 08:28:21 +0000 (UTC) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 5C0B021904; Thu, 27 Jan 2022 08:28:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1643272099; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=GKwmHasx6cNIOtEqFZmKX8VIkRB0CJ5THiVwoA6l1Yo=; b=L37K3Yi1xWUmPAahnJRKqSepNwFhR0VVQ6OgN7TE06U16NG0rkOsOkvSuVip8k+NuH3yiX VXKR64l+Y15lW+8PCoQfffKjRxtBdX0RRse/QNYhRkmhwk/vXzVZ47m9eYNBonaQDT0R62 Mm/GrnMWevJY2DRCtNHnsdXjy8ElbvM= Received: from suse.cz (unknown [10.100.201.86]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by relay2.suse.de (Postfix) with ESMTPS id D11E4A3B8B; Thu, 27 Jan 2022 08:28:17 +0000 (UTC) Date: Thu, 27 Jan 2022 09:28:17 +0100 From: Michal Hocko To: Wei Yang Cc: akpm@linux-foundation.org, mgorman@techsingularity.net, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/memory_hotplug: build zonelist for managed_zone Message-ID: References: <20220127012023.18095-1-richard.weiyang@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220127012023.18095-1-richard.weiyang@gmail.com> Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=suse.com header.s=susede1 header.b=L37K3Yi1; spf=pass (imf01.hostedemail.com: domain of mhocko@suse.com designates 195.135.220.28 as permitted sender) smtp.mailfrom=mhocko@suse.com; dmarc=pass (policy=quarantine) header.from=suse.com X-Rspam-User: nil X-Rspamd-Queue-Id: 0437B40002 X-Stat-Signature: xqb16adtz43fdsmt9s1ka1khajyf6esz X-Rspamd-Server: rspam12 X-HE-Tag: 1643272101-607286 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu 27-01-22 01:20:23, Wei Yang wrote: > During memory hotplug, when online/offline a zone, we need to rebuild > the zonelist for all node. There are two checks to decide whether a zone > would be added to zonelist: > > * one in online_pages/offline_pages to decide necessity > * one in build_zonerefs_node to do real add > > Currently we use different criteria at these two places, which is > different from the original behavior. > > Originally during memory hotplug, zonelist is re-built when zone hasn't > been populated. This in introduced in 'commit 6811378e7d8b ("[PATCH] > wait_table and zonelist initializing for memory hotadd: update zonelists")'. > And at that moment, build_zonelists_node() also use populated_zone() to > decide whether the zone should be added to zonelist. > > While in 'commit 6aa303defb74 ("mm, vmscan: only allocate and reclaim > from zones with pages managed by the buddy allocator")', > build_zonelists_node() changed to use managed_zone() to add zonelist. > But we still use populated_zone() to decide the necessity. > > This patch restore the original behavior by using the same criteria to > add a zone in zonelist during memory hotplug. Why? > Signed-off-by: Wei Yang > Fixes: 6aa303defb74 ("mm, vmscan: only allocate and reclaim from zones with pages managed by the buddy allocator") > CC: Mel Gorman > --- > mm/memory_hotplug.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 2a9627dc784c..8f1906b33937 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1102,11 +1102,11 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, > spin_unlock_irqrestore(&zone->lock, flags); > > /* > - * If this zone is not populated, then it is not in zonelist. > + * If this zone is not managed, then it is not in zonelist. > * This means the page allocator ignores this zone. > * So, zonelist must be updated after online. > */ > - if (!populated_zone(zone)) { > + if (!managed_zone(zone)) { > need_zonelists_rebuild = 1; > setup_zone_pageset(zone); > } > @@ -1985,7 +1985,7 @@ int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages, > /* reinitialise watermarks and update pcp limits */ > init_per_zone_wmark_min(); > > - if (!populated_zone(zone)) { > + if (!managed_zone(zone)) { > zone_pcp_reset(zone); > build_all_zonelists(NULL); > } > -- > 2.33.1 -- Michal Hocko SUSE Labs