When you select a function in the profile tree, we will now display
a per-instruction breakdown of aggregated samples in that function.
This allows us to look much closer at what our code is doing! :^)
We were going from "new JSON format" => "old JSON format" => Event.
This made loading longer profiles unnecessarily slow. It's still pretty
slow, and we should... profile it! :^)
For memory profiles, we now keep track of which allocations are still
live at the end of the selected timeline range and only show those.
This is really cool, I have to admit. :^)
"perfcore" is the file that the kernel generates after a process that
was recording performance events has exited.
This patch teaches ProfileViewer how to load (and symbolicate!) those
files so that we can look at them. This will need a bunch more work
to make it truly useful.
As suggested by Joshua, this commit adds the 2-clause BSD license as a
comment block to the top of every source file.
For the first pass, I've just added myself for simplicity. I encourage
everyone to add themselves as copyright holders of any file they've
added or modified in some significant way. If I've added myself in
error somewhere, feel free to replace it with the appropriate copyright
holder instead.
Going forward, all new source files should include a license header.
Inverting the tree turns all of the innermost stack frames into roots,
allowing them to accumulate their total sample counts with other
instances of the same frame being innermost. This is an essential
feature of any cool profiler, and now we have it. :^)
Instead of fetching these from JSON in every paint event, we now have a
separate "SampleData" vector that can be iterated.
This optimization was made possible by profiling ProfileViewer and then
analyzing the profile with ProfileViewer! :^)
You can now select the time range you want on the profile timeline.
The tree view will update automatically as you alter the range.
Unfortunately this causes the treeview to collapse all of its nodes.
It would be nice to solve this somehow in the future so that nodes
can stay open.
We begin with a simple treeview that shows a recorded profile.
To record and view a profile of a process with <PID>, simply do this:
$ profile <PID> on
... wait while PID does something interesting ...
$ profile <PID> off
$ cat /proc/profile > my-profile.prof
$ ProfileViewer my-profile.prof
