Re: Bisecting tip/auto-x86-next?

Kevin Winchester
2008-06-21T00:00:26Z

Ingo Molnar wrote:
> * Kevin Winchester <kjwinchester@gmail.com> wrote:
>
>>> hm, could you send me the config that triggered this?
>> I will do so tonight when I am home again. It is a UP AMD64 box with
>> a VIA chipset, if that helps.
>>
>>> btw., you can probably ignore this one safely. Also please tell me
>>> at which commit ID you were at when you triggered this warning.
>> Good to know - I will get the commit ID tonight as well, although
>> wouldn't following the same bisection sequence that I did give you the
>> same bisection point? I guess that would assume that linus/master and
>> auto-x86-next haven't changed much since last night, which might not
>> be correct.
>
> yeah, you'd probably not hit that warning with the x86/gart bisection
> sequence. (Assuming the bug is introduced in that branch - so you should
> first check whether pure x86/gart kernel triggers the problem too.)
>
> If you still have the commit ID around then please send it - if you
> dont, no problem, it's no big issue. I wanted to check how wide the
> bisection window is where the warning triggers.
>

I'm sorry - I accidentally checkout out x86/gart to test it before
grabbing the commit ID.

I went ahead with the bisection and found:

8c9fd91a0dc503f085169d44f4360be025f75224 is first bad commit
commit 8c9fd91a0dc503f085169d44f4360be025f75224
Author: Yinghai Lu <yhlu.kernel@gmail.com>
Date: Sun Apr 13 18:42:31 2008 -0700

x86: checking aperture size order

some systems are using 32M for gart and agp when memory is less
than 4G.
Kernel will reject and try to allcate another 64M that is not needed,
and we will waste 64M of perfectly good RAM.

this patch adds a workaround by checking aper_base/order between NB and
agp bridge. If they are the same, and memory size is less than 4G, it
will allow it.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

:040000 040000 848d6e4045a14d01fc0a794d4350d8a84f3ceff6
4a10a52b41309060cd5dc1bf0c322f6d43b2477b M arch
:040000 040000 aa1cee87b1f5b1b30ed03ce6164ad7f404fef2a3
f9ce0aaa1f7d4fdc7bdc5a43285495db53a6f531 M drivers

as the first bad commit. I do not have time to look at the patch right
now, but in case anyone else does, I figured I would post it.

Thanks,

--
Kevin Winchester