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_HELO_NONE,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 11C74C04AB0 for ; Sat, 25 May 2019 09:02:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D986A20862 for ; Sat, 25 May 2019 09:02:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726667AbfEYJCe (ORCPT ); Sat, 25 May 2019 05:02:34 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:17566 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726376AbfEYJCd (ORCPT ); Sat, 25 May 2019 05:02:33 -0400 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 5CA1D8ED1F0315A48D92; Sat, 25 May 2019 17:02:29 +0800 (CST) Received: from [127.0.0.1] (10.177.19.180) by DGGEMS407-HUB.china.huawei.com (10.3.19.207) with Microsoft SMTP Server id 14.3.439.0; Sat, 25 May 2019 17:02:25 +0800 Subject: Re: [PATCH] kernel: sysctl: change ipfrag_high/low_thresh to CTL_ULONG To: Eric Dumazet CC: LKML , Andrew Morton , "David S. Miller" References: <20190524143827.43301-1-wangkefeng.wang@huawei.com> From: Kefeng Wang Message-ID: <049648ab-0e51-c079-b7c8-c9022cae20b4@huawei.com> Date: Sat, 25 May 2019 17:00:03 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.3.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [10.177.19.180] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2019/5/24 23:00, Eric Dumazet wrote: > On Fri, May 24, 2019 at 7:30 AM Kefeng Wang wrote: >> 3e67f106f619 ("inet: frags: break the 2GB limit for frags storage"), >> changes ipfrag_high/low_thread 'type' from int to long, using CTL_ULONG >> instead of CTL_INT to keep consistent. > > What about compatibility with existing applications ? > Will there sysctl() fail if they provide 32bit variable ? > > /proc/sys/net files are text files, but sysctl() system call has been > discouraged for more than a decade. The sysctl() system call is deprecated, so the main purpose of this patch is to keep consistent, but it does set wrong value(eg, set 16000000000 to ipfrag_high_thresh) when use sysctl(). > >