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=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 2DC19C433DF for ; Thu, 13 Aug 2020 07:08:05 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id EA6F420716 for ; Thu, 13 Aug 2020 07:08:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EA6F420716 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 793F06B0005; Thu, 13 Aug 2020 03:08:04 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 743F36B000A; Thu, 13 Aug 2020 03:08:04 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 65A326B000C; Thu, 13 Aug 2020 03:08:04 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0229.hostedemail.com [216.40.44.229]) by kanga.kvack.org (Postfix) with ESMTP id 4F95D6B0005 for ; Thu, 13 Aug 2020 03:08:04 -0400 (EDT) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 11C7B824805A for ; Thu, 13 Aug 2020 07:08:04 +0000 (UTC) X-FDA: 77144666088.03.map60_2c0911326ff2 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin03.hostedemail.com (Postfix) with ESMTP id E6FF326386 for ; Thu, 13 Aug 2020 07:07:52 +0000 (UTC) X-HE-Tag: map60_2c0911326ff2 X-Filterd-Recvd-Size: 2111 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf17.hostedemail.com (Postfix) with ESMTP for ; Thu, 13 Aug 2020 07:07:52 +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 4D1B2B17C; Thu, 13 Aug 2020 07:08:13 +0000 (UTC) Date: Thu, 13 Aug 2020 09:07:44 +0200 From: Michal Hocko To: David Hildenbrand Cc: Charan Teja Reddy , akpm@linux-foundation.org, vbabka@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org, vinmenon@codeaurora.org Subject: Re: [PATCH] mm, page_alloc: fix core hung in free_pcppages_bulk() Message-ID: <20200813070744.GB9477@dhcp22.suse.cz> References: <1597075833-16736-1-git-send-email-charante@codeaurora.org> <3b07d2a6-8ce7-5957-8ca5-a8d977852e14@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3b07d2a6-8ce7-5957-8ca5-a8d977852e14@redhat.com> X-Rspamd-Queue-Id: E6FF326386 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 11-08-20 10:29:24, David Hildenbrand wrote: [...] > I was wondering if we should rather set all pageblocks to > MIGRATE_ISOLATE in online_pages() before doing the online_pages_range() > call, and do undo_isolate_page_range() after onlining is done. > > move_pfn_range_to_zone()->memmap_init_zone() marks all pageblocks > MIGRATE_MOVABLE, and as that function is used also during boot, we could > supply a parameter to configure this. > > This would prevent another race from happening: Having pages exposed to > the buddy ready for allocation in online_pages_range() before the > sections are marked online. > > This would avoid any pages from getting allocated before we're > completely done onlining. This sounds like a reasonable idea to me. > We would need MIGRATE_ISOLATE/CONFIG_MEMORY_ISOLATION also for > CONFIG_MEMORY_HOTPLUG. We already do depend on the memory isolation in the hotremove. Doing the same for hotplug in general makes sense as well. Thanks! -- Michal Hocko SUSE Labs