Re: mem=16MB laptop testing

From: Thomas Schlichter
Date: Wed Oct 15 2003 - 10:40:04 EST


Well, as davej submitted his patch he seems to just have missed a Changeset
applied to the 2.4 tree...:

ChangeSet@xxxxxxxxx 2002-05-06 21:30:10-03:00 hch@xxxxxxxxxxxxx
[PATCH] memsetup fixes (again)

The mem= fixes from Red Hat's tree had a small bug:
if mem= was not actually used with the additional features, but
int plain old way, is used the value as the size of memory it
wants, not the upper limit. The problem with this is that there
is a small difference due to memory holes.

I had one report of a person using mem= to reduce memory size for
a broken i386 chipset thaty only supports 64MB cached and the rest
as mtd/slram device for swap. I got broken as the boundaries changed.

arch/i386/kernel/setup.c@xxxx 2002-04-23 18:52:12-03:00 hch@xxxxxxxxxxxxx

So obviously this should be fixed in the 2.6 tree too!

Regards
Thomas

P.S.: How can be assured that fixes for the 2.4 tree get into the 2.6 tree
when they are needed there, too? I'd wonder if this missed CS is the only
one...

On Wednesday 15 October 2003 15:59, Larry Sendlosky wrote:
> Changeset 1.403.15.8 2002/6/05 davej@xxxxxxx
> [PATCH] large x86 setup cleanup.
>
> Patrick Mochel did a great job here at splitting up some of the larger
> messy parts of arch/i386/kernel/setup.c, and introduced a nice abstraction
> which gives us a much nicer way to ensure we can add workarounds for vendor
> specific bugs / features without polluting other vendor code paths.
>
> Mark Haverkamp also brought this up to date for merging in my tree circa
> 2.5.14, and asides from 1-2 now fixed small thinkos, there haven't been
> any problems.
>
> This also features a workaround for an errata item on stepping C0 of
> the Intel Pentium 4 Xeon, which isn't in your tree yet, where we must
> disable the hardware prefetcher to ensure sane operation.
>
> arch/i386/kernel/setup.c 1.41.1.16 2002/06/03 10:10:19 davej@xxxxxxx
> large x86 setup cleanup.
>
> William Lee Irwin III wrote:
> >On Wed, Oct 15, 2003 at 03:20:54PM +0200, Pavel Machek wrote:
> >>Do you want to say that calculation is different, already? We should
> >>probably make 2.5 version match 2.4 version, that's what users
> >>expect. Who changed it and why?
> >
> >No idea when it changed, but I was at least duly disturbed by the tiny
> >384KB ZONE_NORMAL materializing out of thin air when I booted mem=16m.

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