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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 6F5BDC433DB for ; Wed, 13 Jan 2021 10:58:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1E0D423136 for ; Wed, 13 Jan 2021 10:58:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726931AbhAMK5q (ORCPT ); Wed, 13 Jan 2021 05:57:46 -0500 Received: from mx2.suse.de ([195.135.220.15]:46584 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725858AbhAMK5p (ORCPT ); Wed, 13 Jan 2021 05:57:45 -0500 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 BFAFAAB92; Wed, 13 Jan 2021 10:57:04 +0000 (UTC) Date: Wed, 13 Jan 2021 11:57:01 +0100 From: Oscar Salvador To: Muchun Song Cc: mike.kravetz@oracle.com, akpm@linux-foundation.org, n-horiguchi@ah.jp.nec.com, ak@linux.intel.com, mhocko@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Yang Shi , Michal Hocko Subject: Re: [PATCH v4 1/6] mm: migrate: do not migrate HugeTLB page whose refcount is one Message-ID: <20210113105657.GA26599@linux> References: <20210113052209.75531-1-songmuchun@bytedance.com> <20210113052209.75531-2-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210113052209.75531-2-songmuchun@bytedance.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 13, 2021 at 01:22:04PM +0800, Muchun Song wrote: > diff --git a/mm/migrate.c b/mm/migrate.c > index 4385f2fb5d18..a6631c4eb6a6 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1279,6 +1279,12 @@ static int unmap_and_move_huge_page(new_page_t get_new_page, > return -ENOSYS; > } > > + if (page_count(hpage) == 1) { > + /* page was freed from under us. So we are done. */ > + putback_active_hugepage(hpage); > + return MIGRATEPAGE_SUCCESS; > + } > + I was a bit puzzled as why we did not go to the "goto" block that already does this, but then I saw the put_new_page/new_hpage handlind further down. It could be re-arranged but out of scope, so: Reviewed-by: Oscar Salvador -- Oscar Salvador SUSE L3