Re: [PATCH] x86_64: Make NR_IRQS configurable in Kconfig

Andi Kleen
2006-08-08T02:18:07Z

>
> And it's a pretty nasty one because it can get people into the situation
> where the kernel worked fine for those who released it, but users who
> happen to load more modules (or the right combination of them) will
> experience per-cpu memory exhaustion.

Yes, and a high value will waste a lot of memory for normal users.

> So shouldn't we being scaling the per-cpu memory as well?

If we move it into vmalloc space it would be easy to extend at runtime - just the
virtual address space would need to be prereserved, but then more pages
could be mapped. Maybe we should just do that instead of continuing to kludge around?

Drawback would be some more TLB misses.

-Andi