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 01217C43441 for ; Thu, 22 Nov 2018 10:34:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B1AA020684 for ; Thu, 22 Nov 2018 10:34:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B1AA020684 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 S2405229AbeKVVNJ (ORCPT ); Thu, 22 Nov 2018 16:13:09 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:39739 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2388243AbeKVVNJ (ORCPT ); Thu, 22 Nov 2018 16:13:09 -0500 Received: from DGGEMS408-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 280BA18E34026; Thu, 22 Nov 2018 18:34:15 +0800 (CST) Received: from [10.151.23.176] (10.151.23.176) by smtp.huawei.com (10.3.19.208) with Microsoft SMTP Server (TLS) id 14.3.408.0; Thu, 22 Nov 2018 18:34:10 +0800 Subject: Re: [PATCH 07/10] staging: erofs: separate into init_once / always To: Greg Kroah-Hartman CC: , , Chao Yu , LKML , , Miao Xie References: <20181120143425.43637-1-gaoxiang25@huawei.com> <20181120143425.43637-8-gaoxiang25@huawei.com> <20181122102339.GG3189@kroah.com> From: Gao Xiang Message-ID: <66b90226-5d0e-7344-5220-908aa243b014@huawei.com> Date: Thu, 22 Nov 2018 18:34:10 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: <20181122102339.GG3189@kroah.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.151.23.176] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Greg, On 2018/11/22 18:23, Greg Kroah-Hartman wrote: >> + >> + DBG_BUGON(work->nr_pages); >> + DBG_BUGON(work->vcnt); > How can these ever be triggered? I understand the need for debugging > code when you are writing code, but at this point it shouldn't be needed > anymore, right? I need to avoid some fields is not 0 when the new workgroup is created (because work->nr_pages and work->vcnt == 0 usually after the previous workgroup is freed). But that is not obvious, it is promised by the current logic. In order to not introduce such a issue in the future, or there are some potential race (work->nr_pages and work->vcnt != 0 when the previous workgroup == 0), it need to be noticed to developpers as early as possible. Thanks, Gao Xiang > > thanks, > > greg k-h