Re: [patch] rt: sysprof hrtimer fix

On Fri, Feb 13, 2009 at 01:49:28PM +0100, Ingo Molnar wrote:

* Frederic Weisbecker [off-list ref] wrote:

quoted

So, just a thing.
-rt make the hrtimer's timers running on softirq context because the hrtimer_interrupt
doesn't run as a threaded interrupt, and then it is not preemptible right?

In that case, sysprof will continue to run in hardirq context, as before, and
it will considerably increase the latency. And that matters here.
So I think it is important to put it on the reminder:

hm, not sure. Do you know it numerically how much worst-case overhead it
induces?

	Ingo

Not at all.
But when I find some time, I will compare some rt average tests with and without sysprof.