On Fri, Aug 26, 2016 at 10:37:08AM +0100, Punit Agrawal wrote:

quoted

Will Deacon [off-list ref] writes:

quoted

The easiest thing to do is just TLBI VMALLE1IS for all trapped operations,
but you might want to see how that performs.

That sounds reasonable for correctness. But I suspect we'll have to do
more to claw back some performance. Let me run a few tests and come back
on this.

Assuming I've correctly switched in TCR and replacing the various TLB
operations in this patch with TLBI VMALLE1IS, there is a drop in kernel
build times of ~5% (384s vs 363s).

What do you mean by "switched in TCR"? Why is that necessary if you just
nuke the whole thing? Is the ~5% relative to no trapping at all, or
trapping, but being selective about the operation?

Will