Re: [PATCH] x86/pci: make pci_mem_start to be aligned only -v3

From: Linus Torvalds
Date: Thu Apr 16 2009 - 12:52:06 EST




On Thu, 16 Apr 2009, Jesse Barnes wrote:
>
> Any comments on this one, Linus? Should I include your ack?

I'm not ready to ack it, no. I don't think the suggested patch is very
clean or necessarily sensible as-is. It seems very ad-hoc.

I was literally thinking of something like
"round up from the last RAM by X"
"round up from the last reserved region by Y"
"pick the bigger of the two"

with helper functions for the two cases and comments along the lines of
why we do it. Something that was a bit more obvious about what it's doing
and why.

And no, I realize that the old code isn't that way. But the old code isn't
the issue - the old code is proven over _years_ and years of testing, and
works wonderfully well for a ton of very different machines. It has _one_
single known failure case, and while there clearly must be others, the
point is, the old code is not what needs to be worried about.

So when changing that code that has all that testing, and when the
failures are so nasty and hard to debug and likely only happen on some
random old laptop that has crap e820 tables and _just_ the right amount
of memory, I'd really like the replacement code to be better.

Linus
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