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=-3.8 required=3.0 tests=BAYES_00, 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 C1639C433DB for ; Thu, 28 Jan 2021 05:52:29 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id EA9F664DD6 for ; Thu, 28 Jan 2021 05:52:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EA9F664DD6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AD8756B0005; Thu, 28 Jan 2021 00:52:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A876A6B0006; Thu, 28 Jan 2021 00:52:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 975C56B006C; Thu, 28 Jan 2021 00:52:27 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0237.hostedemail.com [216.40.44.237]) by kanga.kvack.org (Postfix) with ESMTP id 7DC496B0005 for ; Thu, 28 Jan 2021 00:52:27 -0500 (EST) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 3CA128249980 for ; Thu, 28 Jan 2021 05:52:27 +0000 (UTC) X-FDA: 77754113934.28.leaf74_3d109682759d Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin28.hostedemail.com (Postfix) with ESMTP id 1E61B6C37 for ; Thu, 28 Jan 2021 05:52:27 +0000 (UTC) X-HE-Tag: leaf74_3d109682759d X-Filterd-Recvd-Size: 2729 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf41.hostedemail.com (Postfix) with ESMTP for ; Thu, 28 Jan 2021 05:52:26 +0000 (UTC) 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 C450FAB92; Thu, 28 Jan 2021 05:52:24 +0000 (UTC) Date: Thu, 28 Jan 2021 06:52:21 +0100 From: Oscar Salvador To: Mike Kravetz Cc: Michal Hocko , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Naoya Horiguchi , Muchun Song , David Hildenbrand , Matthew Wilcox , Miaohe Lin , Andrew Morton Subject: Re: [PATCH v3 3/5] hugetlb: only set HPageMigratable for migratable hstates Message-ID: <20210128055221.GA3166@localhost.localdomain> References: <20210122195231.324857-1-mike.kravetz@oracle.com> <20210122195231.324857-4-mike.kravetz@oracle.com> <20210127103523.GI827@dhcp22.suse.cz> <2196d93e-f573-7163-183e-0ad2cec7555e@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2196d93e-f573-7163-183e-0ad2cec7555e@oracle.com> 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, Jan 27, 2021 at 03:36:41PM -0800, Mike Kravetz wrote: > Yes, this patch is somewhat optional. It should be a minor improvement > in cases where we are dealing with hpages in a non-migratable hstate. > Although, I do not believe this is the common case. > > The real reason for even looking into this was a comment by Oscar. With > the name change to HPageMigratable, it implies that the page is migratable. > However, this is not the case if the page's hstate does not support migration. > So, if we check the hstate when setting the flag we can eliminate those > cases where the page is certainly not migratable. > > I don't really love this patch. It has minimal functional value. > > Oscar, what do you think about dropping this? Yeah, I remember this topic arose during a discussion of patch#2 in the early versions, about whether the renaming to HPageMigratable made sense. Back then I thought that we could have this in one place at fault-path [1], which should have made this prettier, but it is not the case. True is that the optimization is little, so I am fine with dropping this patch. unmap_and_move_huge_page() fences off pages belonging to non-migratable hstates. [1] https://patchwork.kernel.org/project/linux-mm/patch/20210120013049.311822-3-mike.kravetz@oracle.com/#23914033 Thanks -- Oscar Salvador SUSE L3