Re: Profiling sleep times?

[Peter Zijlstra <peterz@xxxxxxxxxxxxx>]

On Sat, 2011-10-15 at 21:22 +0200, Peter Zijlstra wrote:

> > Sleep time should really just be a different notion of 'cost of the 
> > function/callchain' and fit into the existing scheme, right?
> 
> The problem with andrew's patches is that it wrecks the callchain
> semantics. The waittime tracepoint is in the wakeup path (and hence
> generates the wakee's callchain) whereas they really want the callchain
> of the woken task to show where it spend time.

We could of course try to move the tracepoint into the schedule path, so
we issue it the first time the task gets scheduled after the wakeup, but
I suspect that will just add more overhead, and we really could do
without that.

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