Re: [patch 2/2] x86 NMI-safe INT3 and Page Fault

H. Peter Anvin
2010-07-16T19:30:52Z

On 07/16/2010 11:32 AM, Avi Kivity wrote:
>
> How long would vmalloc_sync_all take with a few thousand mm_struct take?
>
> We share the pmds, yes? So it's a few thousand memory accesses. The
> direct impact is probably negligible, compared to actually loading the
> module from disk. All we need is to make sure the locking doesn't slow
> down unrelated stuff.
>

It's not the memory accesses, it's the need to synchronize all the CPUs.

-hpa