Re: [Bug #11342] Linux 2.6.27-rc3: kernel BUG at mm/vmalloc.c - bisected

Mike Travis
2008-08-26T19:35:16Z

Linus Torvalds wrote:
>
> On Tue, 26 Aug 2008, Mike Travis wrote:
>> The need to allow distros to set NR_CPUS=4096 (and NODES_SHIFT=9) is
>> critical to our upcoming SGI systems using what we have been calling
>> "UV".
>
> That's fine. You can do it. The default kernel will not, because it's
> clearly not safe.
>
> I really don't care what you do to _your_ images. But I will not
> distribute a known-broken kernel, and I will not debug random stack
> overflows that happen in it.
>
> If you want the default kernel to support 4k cores, we'll need to fix the
> stack usage. I don't think that is impossible, but IT IS NOT GOING TO
> HAPPEN for 2.6.27.
>
> And quite frankly, if some vendor like RedHat enables NR_CPUS=4096 by
> default, they are totally and utterly crazy.
>
> But some SGI-specific binary that is meant for SGI machines only, and has
> been extensively tested with the setup used on SGI machines is a different
> thing.
>
> Linus

Ok, thanks for the reply, and looking into this issue. We will "strongly
encourage" our distros to base the relevant releases on 2.6.28. :-)

[Supplying an SGI-specific kernel would not be acceptable to many of our
customers because of the certification issues I mentioned.]

Mike