1071165 - Add a way to profile unregistered threads on b2g

Status: RESOLVED WONTFIX

(Core :: Gecko Profiler, defect)

Description

[Benoit Girard (:BenWa)]

On b2g (linux) if we could get a list of all pthread handles we could monitor non gecko native threads. For more advanced graphics issue this would let us monitor GL driver threads which are not controlled or owned by us.

'/proc/<pid>' can list the tid but we don't have a way to map them to pthread unfortunately. We could maybe interpose pthread_create.

Comment 1

[Benoit Girard (:BenWa)]

Would be it possible to hook pthread_create on b2g to build a list of the pthread handles that gecko could track?

Comment 2

[Jed Davis [:jld] ⟨⏰|UTC-7⟩ ⟦he/him⟧]

(In reply to Benoit Girard (:BenWa) from comment #1)
> Would be it possible to hook pthread_create on b2g to build a list of the
> pthread handles that gecko could track?

Nuwa already hooks pthread_create, so I'd expect the answer to be "yes".

But is there anything where we actually need the pthread_t and not the tid?

Comment 3

[Mike Hommey [:glandium]]

(In reply to Jed Davis [:jld] from comment #2)
> But is there anything where we actually need the pthread_t and not the tid?

pthread_get_stackaddr_np, although I guess that could be replaced by something using the tid.

Comment 4

[Mike Hommey [:glandium]]

Err no, that's OSX only. I was thinking of something else, that gets the thread name.

Comment 5

[Markus Stange [:mstange]]

This bug was about B2G. We may want to do the same thing on other platforms but I don't know how much we're interested in threads that aren't launched by Gecko. I'm going to close this bug for now, we can open a new bug about the other platforms if it comes up again.