From owner-svn-src-head@freebsd.org Wed Mar 29 22:13:11 2017 Return-Path: Delivered-To: svn-src-head@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 98FC4D24A90; Wed, 29 Mar 2017 22:13:11 +0000 (UTC) (envelope-from jkim@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2610:1c1:1:6074::16:84]) by mx1.freebsd.org (Postfix) with ESMTP id B871084E; Wed, 29 Mar 2017 22:13:10 +0000 (UTC) (envelope-from jkim@FreeBSD.org) Subject: Re: svn commit: r316132 - head/sys/boot/i386/boot2 To: Warner Losh , Poul-Henning Kamp Cc: John Baldwin , Ngie Cooper , src-committers , "svn-src-all@freebsd.org" , "svn-src-head@freebsd.org" References: <201703290930.v2T9U3x9087583@repo.freebsd.org> <7448826.asYms2TLO2@ralph.baldwin.cx> <46812.1490823365@critter.freebsd.dk> From: Jung-uk Kim Message-ID: Date: Wed, 29 Mar 2017 18:13:05 -0400 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:52.0) Gecko/20100101 Thunderbird/52.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="dPDir1hwWEaXiXdl6lf46os4jIEP8hw0B" X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 29 Mar 2017 22:13:11 -0000 This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --dPDir1hwWEaXiXdl6lf46os4jIEP8hw0B Content-Type: multipart/mixed; boundary="uHRVEnkA3PMOjXCxlvWMHo3Hq4lbgtp3f"; protected-headers="v1" From: Jung-uk Kim To: Warner Losh , Poul-Henning Kamp Cc: John Baldwin , Ngie Cooper , src-committers , "svn-src-all@freebsd.org" , "svn-src-head@freebsd.org" Message-ID: Subject: Re: svn commit: r316132 - head/sys/boot/i386/boot2 References: <201703290930.v2T9U3x9087583@repo.freebsd.org> <7448826.asYms2TLO2@ralph.baldwin.cx> <46812.1490823365@critter.freebsd.dk> In-Reply-To: --uHRVEnkA3PMOjXCxlvWMHo3Hq4lbgtp3f Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: quoted-printable On 03/29/2017 17:55, Warner Losh wrote: > On Wed, Mar 29, 2017 at 3:36 PM, Poul-Henning Kamp = wrote: >> -------- >> In message <7448826.asYms2TLO2@ralph.baldwin.cx>, John Baldwin writes:= >>> On Wednesday, March 29, 2017 09:30:03 AM Ngie Cooper wrote: >> >>>> Log: >>>> Parameterize out 7680 (15 * 512) as BOOT2SIZE, similar to sys/boot= /i386/zfsboot/... >>>> >>>> This is being done to make it easier to change in the future--this= action might be >>>> needed sooner rather than later because of gcc 6.3.0 bailing, stat= ing that there >>>> is negative free space left (deficit) in the boot2 bootloader. >>>> >>>> MFC after: 2 months >>>> Sponsored by: Dell EMC Isilon >>> >>> This can't be changed. It's baked into the BSD disklabel format. >> >> No it is not, it is baked into FFS, and for UFS2 0, 8, 64 and 256K wor= ks. >=20 > Technically, this is correct. Practically, I'm not sure we can ever > really change it. There are too many tools, scripts, etc that just > know it's 8k, even though most UFS2 systems start 64k into the volume. > UFS1 systems are still around, and there the limit is a hard limit. > And if we grow it, we run the risk of corrupting data beyond the 8k > area we've traditionally used for this. >=20 > So the constants are easy enough to change and it seems like it might > be OK. However, doing it in a safe, anti-foot-shooting way will be the > real elbow grease should someone seriously contemplate the change, > especially since the foot-shooting involved has the potential for > filesystem corruption... >=20 > But gcc 6.3 likely just needs a little TLC experimenting with its > different code generation flags... Interestingly, we had the same discussion eons ago. http://docs.freebsd.org/cgi/mid.cgi?200509081418.47794.jkim FYI... Jung-uk Kim --uHRVEnkA3PMOjXCxlvWMHo3Hq4lbgtp3f-- --dPDir1hwWEaXiXdl6lf46os4jIEP8hw0B Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEl1bqgKaRyqfWXu/CfJ+WJvzb8UYFAljcMXYACgkQfJ+WJvzb 8UbRqwf+Onk9PYlWob5k8yCwrH9t3suOj2e47vUK3z3vVzMQLs7e6mvs1LZiLbaT +QS4LWlAleYh76x6wNqZQkI5hcQJBgsTWT7OSrUcARhHN5Pq1r32wUVVd+u4Nm8B hX5QDG4Lyt0rLFLTDVvEyjG3n1XlTgWFHQphrrm9+0pMF1Dw/1XZcB8EFkpoA/q1 P08F6meWB657O1lIi3aZUQ+GLnWsokAyZUv1NYtyOAGXheFSbY5Bhru03Kntmph0 H7zX5mmkClzBGqU9FHLQvqUmQfsbAhQgpD+sw/y7aj0G93NZp3Uwd5MsHqhCe/C4 xN5jz2riKfoh30ogOglFymt8KX1/yA== =k+UZ -----END PGP SIGNATURE----- --dPDir1hwWEaXiXdl6lf46os4jIEP8hw0B--