Re: [RFC] per-cpu preempt_count

[H. Peter Anvin]

On 08/12/2013 10:35 AM, Linus Torvalds wrote:
> 
> Agreed. Making it atomic would suck, and cancel all advantages of the
> better code generation to access it. Good point.
> 
> And yeah, it could be two variables in the same cacheline or something.
> 

So we would have code looking something like:

	decl %fs:preempt_count
	jnz 1f
	cmpb $0,%fs:need_resched
	je 1f
	call __preempt_schedule
1:

It's a nontrivial amount of code, but would seem a fair bit better than
what we have now, at least.

	-hpa

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