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=-8.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable 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 DB592C433DF for ; Wed, 15 Jul 2020 09:51:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD23B2064B for ; Wed, 15 Jul 2020 09:51:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730913AbgGOJvR (ORCPT ); Wed, 15 Jul 2020 05:51:17 -0400 Received: from [195.135.220.15] ([195.135.220.15]:53436 "EHLO mx2.suse.de" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1730905AbgGOJvR (ORCPT ); Wed, 15 Jul 2020 05:51:17 -0400 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 4F4A5AF85; Wed, 15 Jul 2020 09:51:19 +0000 (UTC) Subject: Re: [PATCH 3/4] mm/hugetlb: make hugetlb migration callback CMA aware To: js1304@gmail.com, Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@lge.com, Christoph Hellwig , Roman Gushchin , Mike Kravetz , Naoya Horiguchi , Michal Hocko , "Aneesh Kumar K . V" , Joonsoo Kim References: <1594789529-6206-1-git-send-email-iamjoonsoo.kim@lge.com> <1594789529-6206-3-git-send-email-iamjoonsoo.kim@lge.com> From: Vlastimil Babka Message-ID: Date: Wed, 15 Jul 2020 11:51:14 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <1594789529-6206-3-git-send-email-iamjoonsoo.kim@lge.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/15/20 7:05 AM, js1304@gmail.com wrote: > From: Joonsoo Kim > > new_non_cma_page() in gup.c requires to allocate the new page that is not > on the CMA area. new_non_cma_page() implements it by using allocation > scope APIs. > > However, there is a work-around for hugetlb. Normal hugetlb page > allocation API for migration is alloc_huge_page_nodemask(). It consists > of two steps. First is dequeing from the pool. Second is, if there is no > available page on the queue, allocating by using the page allocator. > > new_non_cma_page() can't use this API since first step (deque) isn't > aware of scope API to exclude CMA area. So, new_non_cma_page() exports > hugetlb internal function for the second step, alloc_migrate_huge_page(), > to global scope and uses it directly. This is suboptimal since hugetlb > pages on the queue cannot be utilized. > > This patch tries to fix this situation by making the deque function on > hugetlb CMA aware. In the deque function, CMA memory is skipped if > PF_MEMALLOC_NOCMA flag is found. > > Acked-by: Mike Kravetz > Signed-off-by: Joonsoo Kim Acked-by: Vlastimil Babka