Re: [crash, bisected] Re: [PATCH 3/4] x86_64: Fold pda into per cpu area

[Mike Travis <travis@sgi.com>]

H. Peter Anvin wrote:
> Mike Travis wrote:
>> Mike Travis wrote:
>> ...  I'm still re-verifying that the source bits and config options
>>> are identical (it was a later git-remote update), and that in fact it is
>>> the gcc --version, but that may be the conclusion.  
>> ...
>>
>> Yup, it's the gcc --version that makes the difference.  GCC 4.2.0
>> couldn't
>> boot past the grub screen, GCC 4.2.4 made it to the login prompt.
>>
> 
> IIRC, 4.2.0, 4.2.1 and 4.3.0 are known to miscompile the kernel in one
> way or another, however, that is from memory so don't quote me on it.
> 
>     -hpa

This is definitely getting strange...

Ingo's randconfig at:

	http://redhat.com/~mingo/misc/config-Tue_Jul__1_16_48_45_CEST_2008.bad

will only boot and run with gcc-4.2.4, with gcc-4.2.0 it fails at the grub screen.

Other configs like:

	defconfig w/NR_CPUS=4096
	nonuma

will only boot and run with gcc-4.2.0, and does the "failure at grub" screen with
gcc-4.2.4 ...!

The nosmp config works with either.

I'm looking at the generated vmlinux files now (well at least the assembler, I'm
not really familiar enough with the linker objects to look at those.)  I'm also
trying to track which config options changes the behavior so radically.

Any other suggestions?

Thanks!
Mike