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=-2.2 required=3.0 tests=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 53FCFC2D0DA for ; Thu, 26 Dec 2019 09:38:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2FADF2075E for ; Thu, 26 Dec 2019 09:38:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726586AbfLZJiu (ORCPT ); Thu, 26 Dec 2019 04:38:50 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:58866 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725878AbfLZJit (ORCPT ); Thu, 26 Dec 2019 04:38:49 -0500 Received: from DGGEMS401-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 61E2EAFD2DD65EB152BF; Thu, 26 Dec 2019 17:38:47 +0800 (CST) Received: from [10.134.22.195] (10.134.22.195) by smtp.huawei.com (10.3.19.201) with Microsoft SMTP Server (TLS) id 14.3.439.0; Thu, 26 Dec 2019 17:38:43 +0800 Subject: Re: [PATCH] f2fs: introduce DEFAULT_IO_TIMEOUT_JIFFIES To: Vyacheslav Dubeyko , Geert Uytterhoeven CC: Jaegeuk Kim , , Linux Kernel Mailing List , Chao Yu , Linux FS Devel References: <20191223040020.109570-1-yuchao0@huawei.com> <1cc2d2a093ebb15a1fc6eb96d683e918a8d5a7d4.camel@dubeyko.com> From: Chao Yu Message-ID: <8a196bfe-666b-3d7b-e78b-8d3a9bcca978@huawei.com> Date: Thu, 26 Dec 2019 17:38:42 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <1cc2d2a093ebb15a1fc6eb96d683e918a8d5a7d4.camel@dubeyko.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.134.22.195] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/12/25 17:58, Vyacheslav Dubeyko wrote: > On Mon, 2019-12-23 at 09:41 +0100, Geert Uytterhoeven wrote: >> Hi, >> >> CC linux-fsdevel >> >> On Mon, Dec 23, 2019 at 5:01 AM Chao Yu wrote: >>> As Geert Uytterhoeven reported: >>> >>> for parameter HZ/50 in congestion_wait(BLK_RW_ASYNC, HZ/50); >>> >>> On some platforms, HZ can be less than 50, then unexpected 0 >>> timeout >>> jiffies will be set in congestion_wait(). >>> > > > It looks like that HZ could have various value on diferent platforms. > So, why does it need to divide HZ on 50? Does it really necessary? I guess this code was copied from other filesystems, I have no idea why we should use HZ/50 as timeout interval value. > Could it be used HZ only without the division operation? Actually, as Geert pointed out, we can handle that zeroed value parameter inside congestion_wait() to cover all filesystems use cases. Thanks, > > Thanks, > Viacheslav Dubeyko. > > > . >