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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 D16D7C433E0 for ; Wed, 17 Feb 2021 13:54:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5B2C964E5B for ; Wed, 17 Feb 2021 13:54:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5B2C964E5B Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine 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 D29FE6B006C; Wed, 17 Feb 2021 08:54:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CDB366B006E; Wed, 17 Feb 2021 08:54:32 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C179C6B0070; Wed, 17 Feb 2021 08:54:32 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0029.hostedemail.com [216.40.44.29]) by kanga.kvack.org (Postfix) with ESMTP id AB0126B006C for ; Wed, 17 Feb 2021 08:54:32 -0500 (EST) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 67D45180AD838 for ; Wed, 17 Feb 2021 13:54:32 +0000 (UTC) X-FDA: 77827904784.19.A2EB5E0 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf17.hostedemail.com (Postfix) with ESMTP id D6503407F8ED for ; Wed, 17 Feb 2021 13:54:30 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1613570070; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=cGZn21Gwdacac4lJmjWs7og7us1pnxGAs5d/KiaX3Wc=; b=CuQ9syD5a9/plxWcOzZtRtU/gUDxV/DyJ0MWCNEZtRqMzA8snhlchgrKXuAE2Q1zyxViaV 9xFeI788BLis5xvMfejXS8fJoIkVbzlPDoFiCL6Uw6el5F4xYJQRz2cP9+CC345O21bZkR SnLE+caGcsCCV5znjNj/2XAkg36h4PY= Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id D2997B761; Wed, 17 Feb 2021 13:54:30 +0000 (UTC) Date: Wed, 17 Feb 2021 14:54:24 +0100 From: Michal Hocko To: Oscar Salvador 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: References: <20210217100816.28860-1-osalvador@suse.de> <20210217100816.28860-3-osalvador@suse.de> <20210217134649.GB32488@linux> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210217134649.GB32488@linux> X-Stat-Signature: xe7ippz1q8n6egw1j9zfe69pykdx5joe X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: D6503407F8ED Received-SPF: none (suse.com>: No applicable sender policy available) receiver=imf17; identity=mailfrom; envelope-from=""; helo=mx2.suse.de; client-ip=195.135.220.15 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1613570070-197018 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 Wed 17-02-21 14:46:49, Oscar Salvador wrote: > 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? Is this a real life problem? I know we _can_ but I do not see any reasoning _why_ should we care all that much. -- Michal Hocko SUSE Labs