Re: [RFC PATCH] introduce sys_membarrier(): process-wide memory barrier (v3a)

Peter Zijlstra
2010-01-11T21:20:13Z

On Mon, 2010-01-11 at 15:52 -0500, Mathieu Desnoyers wrote:
>
> So the clear bit can occur far, far away in the future, we don't care.
> We'll just send extra IPIs when unneeded in this time-frame.

I think we should try harder not to disturb CPUs, particularly in the
face of RT tasks and DoS scenarios. Therefore I don't think we should
just wildly send to mm_cpumask(), but verify (although speculatively)
that the remote tasks' mm matches ours.