This started a few days ago, I think. STR: 1. In a fresh Firefox profile, install the gecko profiler addon 2. Get a profile The resulting profile doesn't have a Compositor thread.
Probably my fault :) I'll take a look.
(In reply to Nicholas Nethercote [:njn] from comment #1) > Probably my fault :) I'll take a look. Actually, looks like it's something about the compositor itself. I've bisected down to this: changeset: 342278:a5270cca9e28 parent: 342277:764e2c0ad987 parent: 341825:b9c6246f13ea user: Kartikaya Gupta <firstname.lastname@example.org> date: Fri Feb 10 13:57:53 2017 -0500 summary: Merge m-c to graphics I have a few more iterations to go, but I might not get to them until tomorrow.
In the end it is my fault. changeset: 341665:4a894b2316f0 user: Nicholas Nethercote <email@example.com> date: Wed Feb 08 12:01:41 2017 +1100 summary: Bug 1337189 (part 16) - Move all the bools out of Sampler. r=mstange. I haven't yet worked out the problem.
Created attachment 8838519 [details] [diff] [review] Set bools earlier in profiler_start() They must be set before the call to MaybeSetProfiler(), which checks gProfileThreads, and before the gTaskTracer check. This patch fixes the failure of some threads (e.g. Compositor) to be profiled, as well as allowing TaskTracer to start up again!
https://hg.mozilla.org/integration/mozilla-inbound/rev/421a05b31eae5bbc0f49dbcd500da6a0da7cb2bd Bug 1340327 - Set bools earlier in profiler_start(). r=mstange.