Date: Mon, 23 Feb 2004 18:08:36 +0100 From: "Poul-Henning Kamp" <phk@phk.freebsd.dk> To: "M. Warner Losh" <imp@bsdimp.com> Cc: jhb@FreeBSD.org Subject: Re: cvs commit: src/sys/alpha/alpha mem.c promcons.c src/sys/alpha/tlsb zs_tlsb.c src/sys/amd64/amd64 mem.c src/sys/cam cam_xpt.c src/sys/cam/scsi scsi_ch.c scsi_pass.c scsi_pt.c s Message-ID: <9899.1077556116@critter.freebsd.dk> In-Reply-To: Your message of "Mon, 23 Feb 2004 09:09:22 MST." <20040223.090922.112923872.imp@bsdimp.com>
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In message <20040223.090922.112923872.imp@bsdimp.com>, "M. Warner Losh" writes:
>In message: <403A22BB.6010409@freebsd.org>
> Scott Long <scottl@FreeBSD.org> writes:
>: I agree with these arguments. However, I would have liked to have seen
>: a small grace period defined, especially since people are now bumping
>: into the consequences of this change and not knowing why. I plan to do
>: this with the interrupt API change when it comes.
>
>Especially since the code to do this is on the order of:
>
> if (devsw->d_version == 0) {
> printf("Warning, older interface ...");
> devsw->d_flags ^= D_NEEDGIANT;
> devsw->d_version = D_VERSION_00;
> }
>
>unless there are other issues not elucidated (I'm only looking at the
>new code). One could also have had two different bits so APIly it
>changed, but you could whine if only one of them was set.
The semantics of dev_t changed as a result of the refcounting, so
I would have to forcefully break all binary drivers[1] anyway. The
above workaround would not be safe.
And since I had to break them, I decided to have only one break,
and get all three major issues fixed at the same time: dev_t
refcounting, versioning of device driver API and flipping of the
Giant flag.
And I distinctly remember being very vocal about this on current@,
so I think you guys are a little late here...
Poul-Henning
[1] Because experience have shown that the amount of dev_t/makedev(9)
evilness increases with the distance from our CVS repository.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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