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=-5.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 EB56BC433E6 for ; Wed, 17 Feb 2021 13:47:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B188E64E45 for ; Wed, 17 Feb 2021 13:47:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232844AbhBQNrl (ORCPT ); Wed, 17 Feb 2021 08:47:41 -0500 Received: from mx2.suse.de ([195.135.220.15]:48182 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232778AbhBQNre (ORCPT ); Wed, 17 Feb 2021 08:47:34 -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 AFCB2B761; Wed, 17 Feb 2021 13:46:51 +0000 (UTC) Date: Wed, 17 Feb 2021 14:46:49 +0100 From: Oscar Salvador To: Michal Hocko Cc: Andrew Morton , Mike Kravetz , David Hildenbrand , Muchun Song , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] mm: Make alloc_contig_range handle in-use hugetlb pages Message-ID: <20210217134649.GB32488@linux> References: <20210217100816.28860-1-osalvador@suse.de> <20210217100816.28860-3-osalvador@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 17, 2021 at 02:36:31PM +0100, Michal Hocko wrote: > On Wed 17-02-21 11:08:16, Oscar Salvador wrote: > > In-use hugetlb pages can be migrated as any other page (LRU > > and Movable), so let alloc_contig_range handle them. > > > > All we need is to succesfully isolate such page. > > Again, this is missing a problem statement and a justification why we > want/need this. Heh, I was poor in words. "alloc_contig_range() will fail miserably if it finds a HugeTLB page within the range without a chance to handle them. Since HugeTLB pages can be migrated as any other page (LRU and Movable), it does not make sense to bail out. Enable the interface to recognize in-use HugeTLB pages and have a chance to migrate them" What about something along those lines? -- Oscar Salvador SUSE L3