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 0F332C43441 for ; Thu, 22 Nov 2018 10:43:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B0AE520685 for ; Thu, 22 Nov 2018 10:43:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B0AE520685 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 S2390872AbeKVVVv (ORCPT ); Thu, 22 Nov 2018 16:21:51 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:42697 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1732079AbeKVVVv (ORCPT ); Thu, 22 Nov 2018 16:21:51 -0500 Received: from DGGEMS411-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 7DC79DCC11375; Thu, 22 Nov 2018 18:42:57 +0800 (CST) Received: from [10.151.23.176] (10.151.23.176) by smtp.huawei.com (10.3.19.211) with Microsoft SMTP Server (TLS) id 14.3.408.0; Thu, 22 Nov 2018 18:42:52 +0800 Subject: Re: [PATCH 02/10] staging: erofs: fix race when the managed cache is enabled To: Greg Kroah-Hartman CC: , , Chao Yu , LKML , , Miao Xie References: <20181120143425.43637-1-gaoxiang25@huawei.com> <20181120143425.43637-3-gaoxiang25@huawei.com> <20181122101711.GA3189@kroah.com> From: Gao Xiang Message-ID: <55aed87f-196e-9048-6aae-db09bc497664@huawei.com> Date: Thu, 22 Nov 2018 18:42:52 +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: <20181122101711.GA3189@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 18:17, Greg Kroah-Hartman wrote: > Any specific reason why you are not using the refcount.h api instead of > "doing it yourself" with atomic_inc/dec()? > > I'm not rejecting this, just curious. As I explained in the previous email, Re: [PATCH 04/10] staging: erofs: fix `erofs_workgroup_{try_to_freeze, unfreeze}' we need such a function when the value is >= 0, it plays as a refcount, but when the refcount == EROFS_LOCKED_MAGIC (<0, but not 0 as refcount.h), and actually there is no need to introduce a seperate spinlock_t because we don't actually care about its performance (rarely locked). and the corresponding struct is too large for now, we need to decrease its size. Thanks, Gao Xiang > > thanks, > > greg k-h