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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 C088CC43441 for ; Fri, 9 Nov 2018 02:25:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 85B1C20855 for ; Fri, 9 Nov 2018 02:25:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 85B1C20855 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727789AbeKIMDb (ORCPT ); Fri, 9 Nov 2018 07:03:31 -0500 Received: from szxga06-in.huawei.com ([45.249.212.32]:44131 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727390AbeKIMDa (ORCPT ); Fri, 9 Nov 2018 07:03:30 -0500 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id EAD669998938; Fri, 9 Nov 2018 10:25:00 +0800 (CST) Received: from [127.0.0.1] (10.177.29.68) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.408.0; Fri, 9 Nov 2018 10:24:59 +0800 Message-ID: <5BE4EFFA.80608@huawei.com> Date: Fri, 9 Nov 2018 10:24:58 +0800 From: zhong jiang User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Michal Hocko , Anshuman Khandual , Matthew Wilcox , "Andrea Arcangeli" , David Rientjes , Vlastimil Babka , "'Kirill A . Shutemov'" CC: Linux Memory Management List , LKML Subject: Re: [Question] There is a thp count left when the process exits References: <5BE44FDB.6040303@huawei.com> In-Reply-To: <5BE44FDB.6040303@huawei.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.29.68] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org +LKML I can not find the possibility when I check the code. because the mmap_sem and spin_lock will protect the concurrence. I will be appreciated if anyone has some clue. Thanks, zhong jiang On 2018/11/8 23:01, zhong jiang wrote: > Hi, > > Recently, I hit the following issue in linux 3.10 stable. and hard to recur. > > bad pmd ffff880c13ecea80(80000017b16000e7) > > Call Trace: > [] dump_stack+0x19/0x1b > [] warn_slowpath_common+0x70/0xb0 > [] warn_slowpath_null+0x1a/0x20 > [] exit_mmap+0x196/0x1a0 > [] mmput+0x67/0xf0 > [] do_exit+0x28c/0xa60 > [] ? hrtimer_get_res+0x50/0x50 > [] do_group_exit+0x3f/0xa0 > [] get_signal_to_deliver+0x1d0/0x6d0 > [] do_signal+0x57/0x6b0 > [] ? futex_wait_queue_me+0xa2/0x120 > [] ? __do_page_fault+0x183/0x470 > [] do_notify_resume+0x5f/0xb0 > [] int_signal+0x12/0x17 > > BUG: Bad rss-counter state mm:ffff8820136b5dc0 idx:1 val:512 > > The pmd entry show that it is still a thp. but It fails to check and clear the pmd. > hence, page fault will produce a new page for pmd when accessing the page, > which thp count will reduplicative increase. > > Thanks, > zhong jiang