Re: [PATCH 2/2] sched/debug: add sched_update_nr_running tracepoint

[Valentin Schneider]

On 04/09/2019 14:13, Peter Zijlstra wrote:
> On Tue, Sep 03, 2019 at 05:43:40PM +0200, Radim KrÄmÃÅ wrote:
> 
>> Red Hat adapted one of them for the tracepoint framework and created a
>> tool to plot a heatmap of nr_running, where the sched_update_nr_running
>> tracepoint is being used for fine grained monitoring of scheduling
>> imbalance.
> 
> You should be able to reconstruct this from wakeup and switch
> tracepoints.
> 
> 

I never tried to do it myself but know some folks around me gave it a go
(Morten, Qais and maybe even Chris). I can't remember the exact details but
there was something about not getting the right input - duplicated wakeups,
or no migration information (I think sched_migrate doesn't cover all of the
cases) so the information you're building diverges as time progresses.