[tracecompass-dev] Upcoming UI features

[Matthew Khouzam <matthew.khouzam@xxxxxxxxxxxx>]

Hi All,

We're developing some new views and revamping old ones in tracecompass,
I think we are at the point where we can seek feedback.


1- Split the resources view into an Execution context view and an
Interrupts view.

Here's the premise, right now, we have a resource view that is flat out
lying to the user, and also betraying the mental model of an OS kernel.

Why such a statement, the IRQ and SoftIRQ lines are shared across your N
cores. Also, it makes people think that these handlers are some magical
things that don't run on a CPU. IRQs and Soft IRQs are just code. They
may be triggered differently but always run on a cpu.

To fix this, I propose splitting up the views into two:

    A- the CPU view can be called an execution context, it shows what
each cpu core is doing at any given point in time. It can remain the
"resources" view, and we can add GPU/HDD/Network info into it at a later
date, but for now, it has the cpus as before, but as sub-tree elements,
the interrupts are shown. This is very useful when you have located
where a problem is and what to know what it is. Here is a screenshot
*http://i.imgur.com/WhefG0H.png*

    B- the interrupt view. This aggregates Soft IRQs and IRQs by vector
number. I don't see it personnaly as very useful on a microscopic level,
but it may have value on a larger scale. Possible improvements later
could be to show it by handler instead of vector, so you can track an
actual driver and not an IRQ number. It can be a valid way of finding
where a problem is. Here is a screenshot http://i.imgur.com/813DCpN.png

2- Show CPU usage for a given CPU

If you ever manually set your affinities on your threads, this
enhancement will help. It basically will allow you to select a cpu by
right clicking on the resources view CPU entry and a context menu saying
: "Follow CPU <cpu number>" will appear, selecting it will make the cpu
usage view filter out all other cpu information.

This is the first step, if it flies, we will add filters on all views
that have a cpu notion (resources, interrupt, events table)

A screenshot is available here. http://i.imgur.com/diVl8QN.png

3- Follow thread

How often are you tracing to figure out what's going on in your system
and there's no slowdown? How do you know there's a slowdown? You
probably observed a program being slow. This is an option added to the
control flow view to right click on a thread and then a thread wait
density and statistics view can access the information. With these
views, outliers can be easily spotted.

This view should be very useful to locate problems, not to figure them
out, but in a 10 minute trace, this can bring you to the interesting
milliseconds.

Here are two screenshots http://i.imgur.com/jA6ZS16.png 
http://i.imgur.com/hGoOZfj.png

An example of the build with these features can be found here by 12:00
pm today
https://hudson.eclipse.org/tracecompass/view/Obsolete/job/tracecompass-master-rcp-test/lastSuccessfulBuild/artifact/


Finally, here is the album with all the screenshots http://imgur.com/a/45qTl

TL;DR

For all those with limited patience, download this
https://hudson.eclipse.org/tracecompass/view/Obsolete/job/tracecompass-master-rcp-test/lastSuccessfulBuild/artifact/
look at these pics http://imgur.com/a/45qTl


Please tell us if you object to any of the views,

BR Matthew