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=-5.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, URIBL_BLOCKED,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 B6481C43387 for ; Tue, 18 Dec 2018 07:36:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7F0AD214C6 for ; Tue, 18 Dec 2018 07:36:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545118619; bh=OkOewOpB9BbFSl8RXayotfCTp7BOqPBzc9nI/YURLIk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=d2iVu8C/neJx3YP29J7FoRAxXsr6pjWxF/SRt2ht426gLlSaQWaCJM6PWaStpQQ2V BV8c8ne+75eVhBFr+NvkfGS9Lc9kiYEdavS+zQ+28P+/Pmk/8aQcugaOhNeht8NWgg BjBESHNUR9ttib/QHJs6jau+D787xxClRDRRVsMg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726486AbeLRHg6 (ORCPT ); Tue, 18 Dec 2018 02:36:58 -0500 Received: from mx2.suse.de ([195.135.220.15]:35492 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726363AbeLRHg5 (ORCPT ); Tue, 18 Dec 2018 02:36:57 -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 931DBAE0C; Tue, 18 Dec 2018 07:36:56 +0000 (UTC) Date: Tue, 18 Dec 2018 08:36:55 +0100 From: Michal Hocko To: Andrew Morton Cc: Oscar Salvador , vbabka@suse.cz, pavel.tatashin@microsoft.com, rppt@linux.vnet.ibm.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] mm, page_alloc: Fix has_unmovable_pages for HugePages Message-ID: <20181218073655.GB30879@dhcp22.suse.cz> References: <20181217225113.17864-1-osalvador@suse.de> <20181217150726.6eea4942005516d565dae488@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181217150726.6eea4942005516d565dae488@linux-foundation.org> 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 Mon 17-12-18 15:07:26, Andrew Morton wrote: > On Mon, 17 Dec 2018 23:51:13 +0100 Oscar Salvador wrote: > > > v1 -> v2: > > - Fix the logic for skipping pages by Michal > > > > --- > > Please be careful with the "^---$". It signifies end-of-changelog, so > I ended up without a changelog! > > > >From e346b151037d3c37feb10a981a4d2a25018acf81 Mon Sep 17 00:00:00 2001 > > From: Oscar Salvador > > Date: Mon, 17 Dec 2018 14:53:35 +0100 > > Subject: [PATCH] mm, page_alloc: Fix has_unmovable_pages for HugePages > > > > While playing with gigantic hugepages and memory_hotplug, I triggered > > the following #PF when "cat memoryX/removable": > > > > ... > > > > Also, since gigantic pages span several pageblocks, re-adjust the logic > > for skipping pages. > > > > Signed-off-by: Oscar Salvador Acked-by: Michal Hocko > cc:stable? See http://lkml.kernel.org/r/20181217152936.GR30879@dhcp22.suse.cz. I believe nobody is simply using gigantic pages and hotplug at the same time and those pages do not seem to cross cma regions as well. At least not since hugepage_migration_supported stops reporting giga pages as migrateable. That being said, I do not think we really need it in stable but it should be relatively easy to backport so no objection from me to put it there. -- Michal Hocko SUSE Labs