Re: Bisecting tip/auto-x86-next?

Kevin Winchester
2008-06-21T11:50:01Z

Yinghai Lu wrote:
> On Sat, Jun 21, 2008 at 3:39 AM, Kevin Winchester
> <kjwinchester@gmail.com> wrote:
>> Yinghai Lu wrote:
>>> On Sat, Jun 21, 2008 at 3:23 AM, Kevin Winchester
>>> <kjwinchester@gmail.com> wrote:
>>>> On Sat, Jun 21, 2008 at 7:18 AM, Yinghai Lu <yhlu.kernel@gmail.com>
>>>> wrote:
>>>>> On Sat, Jun 21, 2008 at 3:00 AM, Kevin Winchester
>>>>> <kjwinchester@gmail.com> wrote:
>>>>>> Yinghai Lu wrote:
>>>>>>> On Fri, Jun 20, 2008 at 5:00 PM, Kevin Winchester
>>>>>>> <kjwinchester@gmail.com> wrote:
>>>>>>>> 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.
>>>>>>>>
>>>>>>> please send out whole boot logs with "debug" in command line.
>>>>>>>
>>>>>> "debug" in the command line doesn't seem to have any effect on the
>>>>>> printout
>>>>>> (is there some config option I need to use with it?), but here it is
>>>>>> anyway:
>>>>> are you using tip/master?
>>>>>
>>>>> http://people.redhat.com/mingo/sched-devel.git/README
>>>>>
>>>> That log is from tip/x86/gart, which is where the problem patch was
>>>> bisected. Would you get better debugging info from tip/master (which
>>>> includes tip/x86/gart, I believe, and thus would show the problem as
>>>> well)?
>>> tip/master doesn't work?
>>>
>> I will check tip/master now, but I believe it doesn't work.
>>
>> I will also correct myself, the log I sent you was from:
>>
>> 8c9fd91... x86: checking aperture size order
>>
>
> please try attached patch...
>

Thanks for the patch. it fixes the problem for me. tip/master was
indeed showing the problem as well, but it does not once your patch is
applied.

So you can add a:

Tested-by: Kevin Winchester <kjwinchester@gmail.com>

to the patch if you want.

Thanks again,

--
Kevin Winchester