From owner-svn-src-all@freebsd.org Sat Mar 4 22:58:26 2017 Return-Path: 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 0D675CF82B3; Sat, 4 Mar 2017 22:58:26 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from mail.baldwin.cx (bigwig.baldwin.cx [IPv6:2001:470:1f11:75::1]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id D99EF1CD4; Sat, 4 Mar 2017 22:58:25 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from ralph.baldwin.cx (c-73-231-226-104.hsd1.ca.comcast.net [73.231.226.104]) by mail.baldwin.cx (Postfix) with ESMTPSA id D572A10A7DB; Sat, 4 Mar 2017 17:58:24 -0500 (EST) From: John Baldwin To: Pedro Giffuni Cc: Slawa Olhovchenkov , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r314669 - head/sys/i386/conf Date: Sat, 04 Mar 2017 14:51:50 -0800 Message-ID: <7873439.f6BlOXHt6g@ralph.baldwin.cx> User-Agent: KMail/4.14.10 (FreeBSD/11.0-STABLE; KDE/4.14.10; amd64; ; ) In-Reply-To: References: <201703041504.v24F4HMh023937@repo.freebsd.org> <2368011.hGEX4V32U5@ralph.baldwin.cx> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.4.3 (mail.baldwin.cx); Sat, 04 Mar 2017 17:58:24 -0500 (EST) X-Virus-Scanned: clamav-milter 0.99.2 at mail.baldwin.cx X-Virus-Status: Clean 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 \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 04 Mar 2017 22:58:26 -0000 On Saturday, March 04, 2017 03:49:52 PM Pedro Giffuni wrote: >=20 > > Il giorno 04 mar 2017, alle ore 14:43, John Baldwin ha scritto: > >=20 > > On Saturday, March 04, 2017 10:52:46 AM Pedro Giffuni wrote: > >>=20 > >> On 03/04/17 10:32, Slawa Olhovchenkov wrote: > >>> On Sat, Mar 04, 2017 at 03:04:17PM +0000, Pedro F. Giffuni wrote:= > >>>=20 > >>>> Author: pfg > >>>> Date: Sat Mar 4 15:04:17 2017 > >>>> New Revision: 314669 > >>>> URL: https://svnweb.freebsd.org/changeset/base/314669 > >>>>=20 > >>>> Log: > >>>> Drop i486 from the default i386 GENERIC kernel configuration. > >>>>=20 > >>>> 80486 production was stopped by Intel on September 2007. Droppi= ng the 486 > >>>> configuration option from the GENERIC kernel improves performan= ce > >>>> slightly. > >>>>=20 > >>>> Removing I486_CPU is consistent at this time: we don't support = any > >>>> processor without a FPU and the PC-98 arch, which frequently in= volved i486 > >>>> CPUs, is also gone so we don't test such platforms anymore. > >>>=20 > >>> What is realy mean? > >>=20 > >> This means we don't do work-arounds that would be required for raw= 486. > >> Instead we will use the 586 instructions by default. > >=20 > > This doesn't change that. The kernel already has runtime tests in = place > > for new things on 486 and later via cpuid. > >=20 >=20 > Hmm ..then I am wondering if I effectively changed anything? The only change is a 486 now panics on boot when it used to work fine. = :-/ Nothing for other CPUs has changed. =20 > The number came out from an old posting involving buildworld times, w= hich I can=E2=80=99t find now :(. > Things seem to have changed a lot: it was surely using GCC back then,= I don=E2=80=99t believe clang does much distinction about 486 at all. >=20 > BTW, does it make sense to keep i586 in the configuration still? Both= i486 and i586 were once removed but later re-instated in r205336. If anything I'd probably say we should do what bde@ suggested and just remove CPU class entirely (and act as if 486, 586, and 686 are always defined). --=20 John Baldwin