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=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 9E783C433E7 for ; Thu, 3 Sep 2020 07:07:38 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5DDB92071B for ; Thu, 3 Sep 2020 07:07:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5DDB92071B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id F0FD76B005A; Thu, 3 Sep 2020 03:07:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E72AF6B0062; Thu, 3 Sep 2020 03:07:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D89566B0068; Thu, 3 Sep 2020 03:07:37 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0170.hostedemail.com [216.40.44.170]) by kanga.kvack.org (Postfix) with ESMTP id BF1826B005A for ; Thu, 3 Sep 2020 03:07:37 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 6763B3633 for ; Thu, 3 Sep 2020 07:07:36 +0000 (UTC) X-FDA: 77220869712.20.loss33_080f722270a7 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin20.hostedemail.com (Postfix) with ESMTP id 2B472180C060E for ; Thu, 3 Sep 2020 07:07:36 +0000 (UTC) X-HE-Tag: loss33_080f722270a7 X-Filterd-Recvd-Size: 2095 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf17.hostedemail.com (Postfix) with ESMTP for ; Thu, 3 Sep 2020 07:07:35 +0000 (UTC) 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 855D3AD21; Thu, 3 Sep 2020 07:07:35 +0000 (UTC) Date: Thu, 3 Sep 2020 09:07:33 +0200 From: Michal Hocko To: Pavel Tatashin Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org, linux-mm@kvack.org Subject: Re: [PATCH] mm/memory_hotplug: drain per-cpu pages again during memory offline Message-ID: <20200903070733.GO4617@dhcp22.suse.cz> References: <20200901124615.137200-1-pasha.tatashin@soleen.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200901124615.137200-1-pasha.tatashin@soleen.com> X-Rspamd-Queue-Id: 2B472180C060E X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 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 Tue 01-09-20 08:46:15, Pavel Tatashin wrote: [...] > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index e9d5ab5d3ca0..d6d54922bfce 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1575,6 +1575,15 @@ static int __ref __offline_pages(unsigned long start_pfn, > /* check again */ > ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, > NULL, check_pages_isolated_cb); > + /* > + * per-cpu pages are drained in start_isolate_page_range, but if > + * there are still pages that are not free, make sure that we > + * drain again, because when we isolated range we might > + * have raced with another thread that was adding pages to > + * pcp list. I would also add * Forward progress should be still guaranteed because * pages on the pcp list can only belong to MOVABLE_ZONE * because has_unmovable_pages explicitly checks for * PageBuddy on freed pages on other zones. > + */ > + if (ret) > + drain_all_pages(zone); > } while (ret); > > /* Ok, all of our target is isolated. > -- > 2.25.1 > -- Michal Hocko SUSE Labs