Re: Can context switches be faster?

Andrew James Wade
2006-10-13T16:58:24Z

On Friday 13 October 2006 01:29, John Richard Moser wrote:
> True. You can trick the MMU into faulting into the kernel (PaX does
> this to apply non-executable pages-- pages, not halves of VM-- on x86),

Oooh, that is a neat hack!

> but it's orders of magnitude slower as I understand and the petty gains
> you can get over the hardware MMU doing it are not going to outweigh it.

It's architecture-dependent; not all architectures are even capeable of
walking the page table trees in hardware. They compensate with
lightweight traps for TLB cache misses.

Andrew Wade