From owner-svn-src-all@freebsd.org  Thu Dec  8 03:36:24 2016
Return-Path: <owner-svn-src-all@freebsd.org>
Delivered-To: svn-src-all@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id 6F4D5C6C0EB;
 Thu,  8 Dec 2016 03:36:24 +0000 (UTC)
 (envelope-from glebius@FreeBSD.org)
Received: from cell.glebi.us (glebi.us [96.95.210.25])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client CN "cell.glebi.us", Issuer "cell.glebi.us" (not verified))
 by mx1.freebsd.org (Postfix) with ESMTPS id 56FAF1660;
 Thu,  8 Dec 2016 03:36:23 +0000 (UTC)
 (envelope-from glebius@FreeBSD.org)
Received: from cell.glebi.us (localhost [127.0.0.1])
 by cell.glebi.us (8.15.2/8.15.2) with ESMTPS id uB83aLOP024204
 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO);
 Wed, 7 Dec 2016 19:36:21 -0800 (PST)
 (envelope-from glebius@FreeBSD.org)
Received: (from glebius@localhost)
 by cell.glebi.us (8.15.2/8.15.2/Submit) id uB83aLnN024203;
 Wed, 7 Dec 2016 19:36:21 -0800 (PST)
 (envelope-from glebius@FreeBSD.org)
X-Authentication-Warning: cell.glebi.us: glebius set sender to
 glebius@FreeBSD.org using -f
Date: Wed, 7 Dec 2016 19:36:21 -0800
From: Gleb Smirnoff <glebius@FreeBSD.org>
To: Bruce Evans <brde@optusnet.com.au>
Cc: Warner Losh <imp@bsdimp.com>, Mark Johnston <markj@freebsd.org>,
 src-committers <src-committers@freebsd.org>,
 "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>,
 "svn-src-head@freebsd.org" <svn-src-head@freebsd.org>
Subject: Re: svn commit: r309658 - head/sys/vm
Message-ID: <20161208033621.GS27748@FreeBSD.org>
References: <201612062252.uB6Mqjhr019191@repo.freebsd.org>
 <20161207212647.GO27748@FreeBSD.org>
 <CANCZdfonWLwGnJWZ74r1mvQ5mA0_jEzQUAd0TsKvycsmHQ2seg@mail.gmail.com>
 <20161208123844.B935@besplex.bde.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20161208123844.B935@besplex.bde.org>
User-Agent: Mutt/1.7.0 (2016-08-17)
X-BeenThere: svn-src-all@freebsd.org
X-Mailman-Version: 2.1.23
Precedence: list
List-Id: "SVN commit messages for the entire src tree \(except for &quot;
 user&quot; and &quot; projects&quot; \)" <svn-src-all.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-all/>
List-Post: <mailto:svn-src-all@freebsd.org>
List-Help: <mailto:svn-src-all-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/svn-src-all>,
 <mailto:svn-src-all-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 08 Dec 2016 03:36:24 -0000

On Thu, Dec 08, 2016 at 01:07:06PM +1100, Bruce Evans wrote:
B> >> M> +#ifndef BURN_BRIDGES
B> >> M> +/*
B> >> M> + * Provide compatibility sysctls for the benefit of old utilities which exit
B> >> M> + * with an error if they cannot be found.
B> >> M> + */
B> >> M> +SYSCTL_UINT(_vm_stats_vm, OID_AUTO, v_cache_count, CTLFLAG_RD,
B> >> M> +    (u_int *)NULL, 0, "Dummy for compatibility");
B> >> M> +SYSCTL_UINT(_vm_stats_vm, OID_AUTO, v_tcached, CTLFLAG_RD,
B> >> M> +    (u_int *)NULL, 0, "Dummy for compatibility");
B> >> M> +#endif
B> >>
B> >> IMHO, there should be some garbage collecting timeout for them. I'd suggest to
B> >> delete them from head after stable/12 branch is forked.
B> >
B> > Other places define #if BURN_BRUDGES < 1200000 to make this automatic.
B> 
B> The correct ifdef is something like '#if COMPAT_FREEBSD12' to make this
B> non-automatic.  Support for this option should of course be removed some
B> time after the support for COMPAT_43 option.  That is only 25-30 years old.

By the way, can anyone explain me why do we still have COMPAT_43 option?

I also bet $100 against $10 that it is broken in head in many aspects,
since there is no regression suite for it and since nobody uses it.

-- 
Totus tuus, Glebius.