[LLVMdev] Use perf tool for more accurate time measuring on Linux

[Yi Kong]

On 20 May 2014 17:55, Tobias Grosser <tobias at grosser.es> wrote:
> I set it to 2667.000 Mhz on parkas16. You can try if this improves
> something.

I don't see any sign of improvement.

Since we can't get raw data any better, I think we should get this
merged and tested on build bots for a while and see how it goes.

Cheers,
Yi Kong