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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,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 4527CC43460 for ; Mon, 10 May 2021 10:23:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0CEA36144E for ; Mon, 10 May 2021 10:23:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230381AbhEJKYX (ORCPT ); Mon, 10 May 2021 06:24:23 -0400 Received: from mx2.suse.de ([195.135.220.15]:37534 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230351AbhEJKYX (ORCPT ); Mon, 10 May 2021 06:24:23 -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 5497CADDD; Mon, 10 May 2021 10:23:17 +0000 (UTC) Date: Mon, 10 May 2021 12:23:12 +0200 From: Oscar Salvador To: Muchun Song Cc: corbet@lwn.net, mike.kravetz@oracle.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, viro@zeniv.linux.org.uk, akpm@linux-foundation.org, paulmck@kernel.org, pawan.kumar.gupta@linux.intel.com, rdunlap@infradead.org, oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, almasrymina@google.com, rientjes@google.com, willy@infradead.org, mhocko@suse.com, song.bao.hua@hisilicon.com, david@redhat.com, naoya.horiguchi@nec.com, joao.m.martins@oracle.com, duanxiongchun@bytedance.com, fam.zheng@bytedance.com, zhengqi.arch@bytedance.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v23 5/9] mm: hugetlb: defer freeing of HugeTLB pages Message-ID: <20210510102312.GC22664@linux> References: <20210510030027.56044-1-songmuchun@bytedance.com> <20210510030027.56044-6-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210510030027.56044-6-songmuchun@bytedance.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Mon, May 10, 2021 at 11:00:23AM +0800, Muchun Song wrote: > In the subsequent patch, we should allocate the vmemmap pages when > freeing a HugeTLB page. But update_and_free_page() can be called > under any context, so we cannot use GFP_KERNEL to allocate vmemmap > pages. However, we can defer the actual freeing in a kworker to > prevent from using GFP_ATOMIC to allocate the vmemmap pages. > > The __update_and_free_page() is where the call to allocate vmemmmap > pages will be inserted. > > Signed-off-by: Muchun Song > Reviewed-by: Mike Kravetz Reviewed-by: Oscar Salvador -- Oscar Salvador SUSE L3