Re: HT and idle = poll

[Eric Northup <lkml@digitaleric.net>]

On Thursday 06 March 2003 03:08 pm, Linus Torvalds wrote:
> On 6 Mar 2003, Alan Cox wrote:
> > idle=poll probably needs to be doing "rep nop" in a tight loop.
>
> We already do that. It's not enough. The HT thing will still steal cycles
> continually, since the "rep nop" is really only equivalent to a
> "sched_yield()".

(Perhaps a naive idea) Right now, there is a single "rep nop" per poll.  What 
happens if you unroll the loop a few times:

while (!condition) {
	cpu_relax();
	cpu_relax();
	cpu_relax();
}

?  I have no HT hardware so can't test this.

-Eric