Re: [tracecompass-dev] Towards Flamegraphs, callgraphs, callstacks and p

[Matthew Khouzam <matthew.khouzam@xxxxxxxxxxxx>]

Very interesting, thanks for the info.

For the color palette, would you see it as global or on a per-view
level. Should foo() be the same color in the callstack and flamegraph? I
would argue so, but I'm not too strongly opinionated on that.

On 16-07-27 03:30 PM, Jonathan Rajotte Julien wrote:
>
>
> On 2016-07-27 02:51 PM, Matthew Khouzam wrote:
>> Trace Compass had a call stack view for several years now, at this point
>> we are adding analyses on top of the call stack.
>>
>> A reminder: call stacks show entries and exits of functions in time and
>> the caller/callee structure.
>>
>> The information in it is very good, however, there is a lot of
>> information that may overwhelm users that want to just see which
>> function is taking too long to run.
>>
>> Right now, we have a view that looks at the entries and classifies them
>> by duration (Function Duration Distribution) this is very interesting,
>> but does not summarize enough, so we are trying to bring in flame graph
>> views to help in that respect.
>>
>> Reminder 2: flame graphs are aggregate views that discard timing
>> information but keep total times
>>
>> So a flame graph will help show total duration times and a bit of call
>> hierarchy. If you need more info, I suggest reading up this blog:
>>
>> http://www.brendangregg.com/FlameGraphs/cpuflamegraphs.html#FlameGraph
>>
>> Now we have some issues with the flame graph.
>>
>> Let's go over some contention points.
>>
>> Colors:
>> * We maintain the colors of the call stack view
>> - OR -
>> * We set the colors to be red to yellow like the originals?
>
> If you take a look a the github page for the flame graph tool [1]
> there is a palette option.
> I do not see a problem using our own color palette (meaningful
> information) by default (first step)
> as long as it can be customized (second step).
>
> [1] https://github.com/brendangregg/FlameGraph#options
>
>>
>> I am leaning very very strongly towards option one, it give a lot more
>> meaning to the colors.
>>
>> Stalagtites vs Stalagmites:
>> * We show the root function on the top and go down with the deeper
>> function
>> - OR -
>> * We keep them as the de facto standard of bottom up.
>>
>> There are some advantages to going from top down:
>> 1- it is inline with the rest of the views
>> 2- if you have a smaller window, the more interesting stuff is shown
>> 3- if you choose to collapse a thread, the control is intuitive (no
>> upward collapsing)
>>
>> there is however a HUGE con:
>> 1- it is not what people are expecting to see
>
> The flame graph from the chrome profile tool is a top-down flame
> graph[2][3].
> If the only argument for bottom-up is user expectation ... chrome have
> a lot of dev users ...
>
> [2] http://i.imgur.com/hLQhGV6.png
> [3]
> https://developers.google.com/web/tools/chrome-devtools/profile/rendering-tools/js-execution?hl=en#view-profile
>
> Cheers!
>
>>
>> Are there any thoughts on the two points?
>> Do you want classic flame graph views?
>> Do you want it going up or down?
>>
>> _______________________________________________
>> tracecompass-dev mailing list
>> tracecompass-dev@xxxxxxxxxxx
>> To change your delivery options, retrieve your password, or
>> unsubscribe from this list, visit
>> https://dev.eclipse.org/mailman/listinfo/tracecompass-dev
>