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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_PASS 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 477D8C43387 for ; Mon, 17 Dec 2018 15:34:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2209920578 for ; Mon, 17 Dec 2018 15:34:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387661AbeLQPez (ORCPT ); Mon, 17 Dec 2018 10:34:55 -0500 Received: from mx2.suse.de ([195.135.220.15]:33376 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2387522AbeLQPeu (ORCPT ); Mon, 17 Dec 2018 10:34:50 -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 28E1FAC15; Mon, 17 Dec 2018 15:34:49 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 17 Dec 2018 16:34:48 +0100 From: osalvador@suse.de To: Michal Hocko Cc: akpm@linux-foundation.org, vbabka@suse.cz, rppt@linux.vnet.ibm.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, owner-linux-mm@kvack.org Subject: Re: [PATCH] mm, page_alloc: Fix has_unmovable_pages for HugePages In-Reply-To: <20181217152936.GR30879@dhcp22.suse.cz> References: <20181217150651.16176-1-osalvador@suse.de> <20181217152936.GR30879@dhcp22.suse.cz> Message-ID: X-Sender: osalvador@suse.de User-Agent: Roundcube Webmail Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018-12-17 16:29, Michal Hocko wrote: > On Mon 17-12-18 16:06:51, Oscar Salvador wrote: > [...] >> diff --git a/mm/page_alloc.c b/mm/page_alloc.c >> index a6e7bfd18cde..18d41e85f672 100644 >> --- a/mm/page_alloc.c >> +++ b/mm/page_alloc.c >> @@ -8038,11 +8038,12 @@ bool has_unmovable_pages(struct zone *zone, >> struct page *page, int count, >> * handle each tail page individually in migration. >> */ >> if (PageHuge(page)) { >> + struct page *head = compound_head(page); >> >> - if (!hugepage_migration_supported(page_hstate(page))) >> + if (!hugepage_migration_supported(page_hstate(head))) >> goto unmovable; > > OK, this makes sense. > >> >> - iter = round_up(iter + 1, 1<> + iter = round_up(iter + 1, 1< > but this less so. You surely do not want to move by the full hugetlb > page when you got a tail page, right? You could skip too much. You have > to consider page - head into the equation. Argh, you're quite right. I will amend it in the next version.