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 7F904C433E0 for ; Wed, 24 Feb 2021 08:33:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2A8F064EC9 for ; Wed, 24 Feb 2021 08:33:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234381AbhBXIdD (ORCPT ); Wed, 24 Feb 2021 03:33:03 -0500 Received: from mx2.suse.de ([195.135.220.15]:44288 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232563AbhBXIcj (ORCPT ); Wed, 24 Feb 2021 03:32:39 -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 F39D9AF3E; Wed, 24 Feb 2021 08:31:55 +0000 (UTC) Date: Wed, 24 Feb 2021 09:31:49 +0100 From: Oscar Salvador To: Muchun Song Cc: Mike Kravetz , Jonathan Corbet , Thomas Gleixner , mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, Peter Zijlstra , viro@zeniv.linux.org.uk, Andrew Morton , paulmck@kernel.org, mchehab+huawei@kernel.org, pawan.kumar.gupta@linux.intel.com, Randy Dunlap , oneukum@suse.com, anshuman.khandual@arm.com, jroedel@suse.de, Mina Almasry , David Rientjes , Matthew Wilcox , Michal Hocko , "Song Bao Hua (Barry Song)" , David Hildenbrand , HORIGUCHI =?utf-8?B?TkFPWUEo5aCA5Y+jIOebtOS5nyk=?= , Joao Martins , Xiongchun duan , linux-doc@vger.kernel.org, LKML , Linux Memory Management List , linux-fsdevel Subject: Re: [External] Re: [PATCH v16 4/9] mm: hugetlb: alloc the vmemmap pages associated with each HugeTLB page Message-ID: <20210224083145.GA14894@linux> References: <20210219104954.67390-1-songmuchun@bytedance.com> <20210219104954.67390-5-songmuchun@bytedance.com> <13a5363c-6af4-1e1f-9a18-972ca18278b5@oracle.com> <20210223092740.GA1998@linux> <20210223104957.GA3844@linux> <20210223154128.GA21082@localhost.localdomain> <20210223223157.GA2740@localhost.localdomain> 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-fsdevel@vger.kernel.org On Wed, Feb 24, 2021 at 11:47:49AM +0800, Muchun Song wrote: > I have been looking at the dequeue_huge_page_node_exact(). > If a PageHWPoison huge page is in the free pool list, the page will > not be allocated to the user. The PageHWPoison huge page > will be skip in the dequeue_huge_page_node_exact(). Yes, now I see where the problem lies. hugetlb_no_page()->..->dequeue_huge_page_node_exact() will fail if the only page in the pool is hwpoisoned, as expected. Then alloc_buddy_huge_page_with_mpol() will be tried, but since surplus_huge_pages counter is stale, we will fail there. That relates to the problem Mike pointed out, that we should decrease again the surplus_huge_pages. I think hwpoisoned pages should not be in the free pool though. Probably we want to take them off when we notice we have one: e.g: dequeue_huge_page_node_exact could place the page in another list and place it back in case it was unpoisoned. But anyway, that has nothing to do with this (apart from the surplus problem). -- Oscar Salvador SUSE L3