Re: [patch 2/8] Implement always-locked bit ops, for memory shared with an SMP hypervisor.

Jeremy Fitzhardinge
2006-08-03T00:35:59Z

Christoph Lameter wrote:
> I think I asked this before....
>
> Would it not be simpler to always use the locked implementation on UP? At
> least when the kernel is compiled with hypervisor support? This is going
> to add yet another series of bit operations

You mean make the standard bit-ops atomic on UP when compiling for
CONFIG_PARAVIRT? We think its too much of a burden; there are only a
few operations which must be locked in the hypervisor case, and bit ops
are used everywhere. I'd like to get it to the point where there's no
significant overhead in configuring for PARAVIRT, even if you run on
native hardware.

J