Re: Breakage caused by unreviewed patch in x86 tree

From: Arjan van de Ven
Date: Sun Apr 27 2008 - 19:07:44 EST


On Sun, 27 Apr 2008 16:00:41 -0700 (PDT)
David Miller <davem@xxxxxxxxxxxxx> wrote:

> From: Arjan van de Ven <arjan@xxxxxxxxxxxxx>
> Date: Sun, 27 Apr 2008 15:58:03 -0700
>
> > On Sun, 27 Apr 2008 16:51:25 -0400
> > James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > > This patch:
> > >
> > > commit 6371b495991debfd1417b17c2bc4f7d7bae05739
> > > Author: Ingo Molnar <mingo@xxxxxxx>
> > > Date: Wed Jan 30 13:33:40 2008 +0100
> > >
> > > x86: change ioremap() to default to uncached
> > >
> > > As far as I can tell went blindly into the x86 tree without being
> > > shared on any mailing list at all. How can something that
> > > completely alters the semantics of ioremap on x86 platforms go in
> > > without any review.
> >
> > it changed from "whatever coinflip you got" to "predictable
> > outcome".
>
> You're making technical responses to a question about process.

ok on a process side it is basically a "go from 99.9% to 100%" bugfix ;(

Anyone who claims that ioremap() on x86 was cached before doesn't understand the issue,
it was NOT cached. It was "almost always uncached". The bugfix here is to take away the
"almost" part.
Should that have been posted to lkml more vocally? Wouldn't have hurt. No argument about that.
Is it as big a deal as this thread makes it sound? Absolutely not! The change in behavior
or even semantics is almost zero.


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