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=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 83286C2D0E4 for ; Mon, 23 Nov 2020 14:20:27 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 187C72075A for ; Mon, 23 Nov 2020 14:20:24 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="b0LkeT2q" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 187C72075A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.34418.65448 (Exim 4.92) (envelope-from ) id 1khChM-0006Y9-5t; Mon, 23 Nov 2020 14:20:08 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 34418.65448; Mon, 23 Nov 2020 14:20:08 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1khChM-0006Y2-2v; Mon, 23 Nov 2020 14:20:08 +0000 Received: by outflank-mailman (input) for mailman id 34418; Mon, 23 Nov 2020 14:20:07 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1khChL-0006UD-19 for xen-devel@lists.xenproject.org; Mon, 23 Nov 2020 14:20:07 +0000 Received: from mail-yb1-xb42.google.com (unknown [2607:f8b0:4864:20::b42]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 4095cb29-3c24-4e18-89b6-b4f387cf8a58; Mon, 23 Nov 2020 14:20:06 +0000 (UTC) Received: by mail-yb1-xb42.google.com with SMTP id v92so16085706ybi.4 for ; Mon, 23 Nov 2020 06:20:06 -0800 (PST) Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1khChL-0006UD-19 for xen-devel@lists.xenproject.org; Mon, 23 Nov 2020 14:20:07 +0000 X-Inumbo-ID: 4095cb29-3c24-4e18-89b6-b4f387cf8a58 Received: from mail-yb1-xb42.google.com (unknown [2607:f8b0:4864:20::b42]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 4095cb29-3c24-4e18-89b6-b4f387cf8a58; Mon, 23 Nov 2020 14:20:06 +0000 (UTC) Received: by mail-yb1-xb42.google.com with SMTP id v92so16085706ybi.4 for ; Mon, 23 Nov 2020 06:20:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=WUYMqcUnfpAQa1YuH9tQ3ze5bp2bxaoGLXc9Sg/470Y=; b=b0LkeT2q71Z3peIccxL7MkU5QadaCN3igdEC89IE4ykmdOxIlhuoo/0+H7pQCoNmlh 0UX19Z7soasUpz2fDZHX56luUWrH4GLKAJ9K28HwPu9km7qlcvasqfBffaQW+LtXvh6a fVP4J8wQFxbi1QWFB10Wsq9dLONxRShLcqQtcaktrZCy3tSRV5R4FOw2MSdgwNuCxNwd cKQMyE/jYgmlc9Qm972BZKz9xJaasT5iW6gpZgai8YpCh1sxJNgZFzlfCpv21Fvd7rwb akOsznbnFT4mJT95mXFDUPnplTdAJirWAcm8YfzHFRAfOGn9Vk91PuRcq7JipLelDPMB VWgQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=WUYMqcUnfpAQa1YuH9tQ3ze5bp2bxaoGLXc9Sg/470Y=; b=WEVpTVA0ExJe7F3FkrQ+gV5WOeNpNy7EgvnBfVaqYI1Aritms6j2zKWXZ97rwlqePN aQPDn2p1+U9ZSmheUB18SEtcNE6RFE4O0cdOyTgjLRuyDVQL+5PkAckHMzlgNFu7iQvw 8F66MiIB62VDdTwdnQoLAsGO/Mooe54jf9LIT+C2x2NDJXrHo8tvTNZUY4xqihVJ+aCW bVspBgEhyYdB/dqc8pjDOD+016M7ucJooX3TYrUeHabNeNZLLqMmyxVdXVCyRuQwpqac dxIwebxtFPf2sBSIc0HpyKJWa5euiVcCGljKbTGqJswJscQ8ix3uVcNu61oHxVln5oqy 1jQA== X-Gm-Message-State: AOAM5335RSXeXrz/fKugIfPdsH0VtC8/mudHPYnUrSZ+Hl0R7G0LckFT hAdqUReZHlMQTFEVapWZlwoybRCN3mec4N72yaU= X-Google-Smtp-Source: ABdhPJyiJqjBIpEzWlk5pyqpoGG3+KpoWdKnlyza2YA6ODhXnRhATytwh5Bq+iGOzNqc5gs+zuqHC8iB1cjfDTXU/ik= X-Received: by 2002:a25:bcc7:: with SMTP id l7mr32380985ybm.115.1606141205830; Mon, 23 Nov 2020 06:20:05 -0800 (PST) MIME-Version: 1.0 References: <20201120105344.4345c14e@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <202011201129.B13FDB3C@keescook> <20201120115142.292999b2@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> <202011220816.8B6591A@keescook> <9b57fd4914b46f38d54087d75e072d6e947cb56d.camel@HansenPartnership.com> <1c7d7fde126bc0acf825766de64bf2f9b888f216.camel@HansenPartnership.com> In-Reply-To: <1c7d7fde126bc0acf825766de64bf2f9b888f216.camel@HansenPartnership.com> From: Miguel Ojeda Date: Mon, 23 Nov 2020 15:19:55 +0100 Message-ID: Subject: Re: [PATCH 000/141] Fix fall-through warnings for Clang To: James Bottomley Cc: Kees Cook , Jakub Kicinski , "Gustavo A. R. Silva" , linux-kernel , alsa-devel@alsa-project.org, amd-gfx@lists.freedesktop.org, bridge@lists.linux-foundation.org, ceph-devel@vger.kernel.org, cluster-devel@redhat.com, coreteam@netfilter.org, devel@driverdev.osuosl.org, dm-devel@redhat.com, drbd-dev@lists.linbit.com, dri-devel@lists.freedesktop.org, GR-everest-linux-l2@marvell.com, GR-Linux-NIC-Dev@marvell.com, intel-gfx@lists.freedesktop.org, intel-wired-lan@lists.osuosl.org, keyrings@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-acpi@vger.kernel.org, linux-afs@lists.infradead.org, Linux ARM , linux-arm-msm@vger.kernel.org, linux-atm-general@lists.sourceforge.net, linux-block@vger.kernel.org, linux-can@vger.kernel.org, linux-cifs@vger.kernel.org, Linux Crypto Mailing List , linux-decnet-user@lists.sourceforge.net, Ext4 Developers List , linux-fbdev@vger.kernel.org, linux-geode@lists.infradead.org, linux-gpio@vger.kernel.org, linux-hams@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-i3c@lists.infradead.org, linux-ide@vger.kernel.org, linux-iio@vger.kernel.org, linux-input , linux-integrity@vger.kernel.org, linux-mediatek@lists.infradead.org, Linux Media Mailing List , linux-mmc@vger.kernel.org, Linux-MM , linux-mtd@lists.infradead.org, linux-nfs@vger.kernel.org, linux-rdma@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-scsi@vger.kernel.org, linux-sctp@vger.kernel.org, linux-security-module@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-usb@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-wireless , Network Development , netfilter-devel@vger.kernel.org, nouveau@lists.freedesktop.org, op-tee@lists.trustedfirmware.org, oss-drivers@netronome.com, patches@opensource.cirrus.com, rds-devel@oss.oracle.com, reiserfs-devel@vger.kernel.org, samba-technical@lists.samba.org, selinux@vger.kernel.org, target-devel@vger.kernel.org, tipc-discussion@lists.sourceforge.net, usb-storage@lists.one-eyed-alien.net, virtualization@lists.linux-foundation.org, wcn36xx@lists.infradead.org, "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , xen-devel@lists.xenproject.org, linux-hardening@vger.kernel.org, Nick Desaulniers , Nathan Chancellor , Miguel Ojeda , Joe Perches Content-Type: text/plain; charset="UTF-8" On Sun, Nov 22, 2020 at 11:36 PM James Bottomley wrote: > > Well, it seems to be three years of someone's time plus the maintainer > review time and series disruption of nearly a thousand patches. Let's > be conservative and assume the producer worked about 30% on the series > and it takes about 5-10 minutes per patch to review, merge and for > others to rework existing series. So let's say it's cost a person year > of a relatively junior engineer producing the patches and say 100h of > review and application time. The latter is likely the big ticket item > because it's what we have in least supply in the kernel (even though > it's 20x vs the producer time). How are you arriving at such numbers? It is a total of ~200 trivial lines. > It's not about the risk of the changes it's about the cost of > implementing them. Even if you discount the producer time (which > someone gets to pay for, and if I were the engineering manager, I'd be > unhappy about), the review/merge/rework time is pretty significant in > exchange for six minor bug fixes. Fine, when a new compiler warning > comes along it's certainly reasonable to see if we can benefit from it > and the fact that the compiler people think it's worthwhile is enough > evidence to assume this initially. But at some point you have to ask > whether that assumption is supported by the evidence we've accumulated > over the time we've been using it. And if the evidence doesn't support > it perhaps it is time to stop the experiment. Maintainers routinely review 1-line trivial patches, not to mention internal API changes, etc. If some company does not want to pay for that, that's fine, but they don't get to be maintainers and claim `Supported`. Cheers, Miguel