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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 BB378C33C9E for ; Fri, 17 Jan 2020 18:38:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 91C3E2082F for ; Fri, 17 Jan 2020 18:38:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="fruG0QB/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729240AbgAQSiE (ORCPT ); Fri, 17 Jan 2020 13:38:04 -0500 Received: from mail-qt1-f195.google.com ([209.85.160.195]:44774 "EHLO mail-qt1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726603AbgAQSiE (ORCPT ); Fri, 17 Jan 2020 13:38:04 -0500 Received: by mail-qt1-f195.google.com with SMTP id w8so8096439qts.11; Fri, 17 Jan 2020 10:38:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:date:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to :user-agent; bh=B2QYMnKFf/fcxzGZsqSaFpUv68BVpaJGzVeEGxBvjew=; b=fruG0QB/ncmSEH66MAEoRQM52PMTvjKnk6RXGZ7atnpIlt/W6g29QWbRrU28pNEsrm c6vyrI32CHHNcmpd0PfCMMLGP9CDhhLtYtXQyhEVNMYomd8ruht4aFaKkDbk5F5LLEwF KJXWHcvd3Jk4MSeTXK0xg5bz2NgNErf/edGu3in8Kpk+aNZ5Cm85Mq1bcMOiYnBglJS+ JW8OHsXYwMXrnJGIgMCod0qVZdXtXqVKhnSdVXwhcJueEw49FrmRgB3ZrZvVTPxyYMxG jv5q4qAqYG0HCganCx2oic9mAlX8HUL0BsT6ldOGr6v/QimQ1Svg3jzNMNcmTcrXaNi4 xZIQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:date:to:cc:subject:message-id :references:mime-version:content-disposition :content-transfer-encoding:in-reply-to:user-agent; bh=B2QYMnKFf/fcxzGZsqSaFpUv68BVpaJGzVeEGxBvjew=; b=GLygpWP1faEIoTefG+n2rsf9rRpWRUSpeivRwnjwZBc5TAt63GFSX9Ayo24wDcwyNo VbQd9wJXNR9hpPEuQOAhDDWMqV8z33YDqJ9SAen2xvKpylvWOavJLd4csneGnBMY5ZRm 6Cpm4jaKajYPbC4yhSZSzSeVKcGRT4eqDkhxbGFI+Wyew6eXmcR07OqK1c+7TN23+a27 tnbrevda2+yEVl10XO99aasmJ5Iw/EYq3FZ/NjJr+kdmmx0UoamTFAox5j46dj/igtG4 2o0ruDYQaqJFPSwjHxithHWL9A0Cp8HPwknZD5gyPA/giFxE7EsZFUkCGLOuCY3C4c5N tG/Q== X-Gm-Message-State: APjAAAWdXwEDP5vyBC2syjGuzW8cxTptGLh5e2ofJmTKeYwfdEy3Y3wV ViSwpcf+ZhB8VMQr7+78kaI= X-Google-Smtp-Source: APXvYqxfcPbp81Ww7YtN4cnsDMKrKyQXnFvzj6wQg2OY4pren+17ftRh6bVyOrgBFTZl9q0wjaW8OQ== X-Received: by 2002:ac8:124a:: with SMTP id g10mr9031376qtj.303.1579286283330; Fri, 17 Jan 2020 10:38:03 -0800 (PST) Received: from rani.riverdale.lan ([2001:470:1f07:5f3::b55f]) by smtp.gmail.com with ESMTPSA id m21sm12151734qka.117.2020.01.17.10.38.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Jan 2020 10:38:02 -0800 (PST) From: Arvind Sankar X-Google-Original-From: Arvind Sankar Date: Fri, 17 Jan 2020 13:38:01 -0500 To: Eric Dumazet Cc: Arvind Sankar , Peter Zijlstra , Shaokun Zhang , David Miller , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, jinyuqi@huawei.com, kuznet@ms2.inr.ac.ru, yoshfuji@linux-ipv6.org, edumazet@google.com, guoyang2@huawei.com, Will Deacon Subject: Re: [PATCH] net: optimize cmpxchg in ip_idents_reserve Message-ID: <20200117183800.GA2649345@rani.riverdale.lan> References: <1579058620-26684-1-git-send-email-zhangshaokun@hisilicon.com> <20200116.042722.153124126288244814.davem@davemloft.net> <930faaff-4d18-452d-2e44-ef05b65dc858@gmail.com> <1b3aaddf-22f5-1846-90f1-42e68583c1e4@gmail.com> <430496fc-9f26-8cb4-91d8-505fda9af230@hisilicon.com> <20200117123253.GC14879@hirez.programming.kicks-ass.net> <7e6c6202-24bb-a532-adde-d53dd6fb14c3@gmail.com> <20200117180324.GA2623847@rani.riverdale.lan> <94573cea-a833-9b48-6581-8cc5cdd19b89@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <94573cea-a833-9b48-6581-8cc5cdd19b89@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 17, 2020 at 10:16:45AM -0800, Eric Dumazet wrote: > Wasńt it the case back in 2016 already for linux-4.8 ? > > What will prevent someone to send another report to netdev/lkml ? > > -fno-strict-overflow support is not a prereq for CONFIG_UBSAN. > > Fact that we kept in lib/ubsan.c and lib/test_ubsan.c code for > test_ubsan_add_overflow() and test_ubsan_sub_overflow() is disturbing. > No, it was bumped in 2018 in commit cafa0010cd51 ("Raise the minimum required gcc version to 4.6"). That raised it from 3.2 -> 4.6.