[tor-dev] Using linux perf tool to look at sleep times

[Jim Newsome]

cc tor-dev for real this time :)

On 8/31/20 17:23, Jim Newsome wrote:
> Hi David, (cc tor-dev in case others are interested or know anything
> about it)
>
> I'm told you're the local expert on the linux perf tool :). I'm using it
> to profile sleep times in Shadow, using the instructions here:
> https://perf.wiki.kernel.org/index.php/Tutorial#Profiling_sleep_times
>
> perf unfortunately splits the data both by what the scheduler is
> switching from (which I want) and what it's switching to (which I
> don't). e.g. I have two separate lines:
>
> +   13.46%    13.46%  prev_comm=shadow prev_pid=24996 prev_prio=120
> prev_state=S ==> next_comm=swapper/3 next_pid=0 next_prio=120
> +   11.57%    11.57%  prev_comm=shadow prev_pid=24996 prev_prio=120
> prev_state=S ==> next_comm=swapper/2 next_pid=0 next_prio=120
>
> I'd rather these were merged into a single "prev_comm=shadow
> prev_pid=24996 prev_prio=120 prev_state=S" bucket.
>
> Any ideas?
>