Hi,

On 28/02/2019 03:02, Arthur D. wrote:
> Hello, guys.
>
> Ivaylo Dimitrov <ivo.g.dimitrov.75@???> wrote:
>> Could be, afaik Nokia did lots of work trying to squeeze the last bit
>> of performance from powervr
>
> Ivaylo, it's not about squeezing the last bit of performance.
> It's about 5 FPS vs 50 FPS.

Sure, and we'll get to figuring out what the important things are.

> Merlijn Wajer <merlijn@???> wrote:
>> OK. As I indicated above, I feel the same way. But I can't help but
>> wonder if such an exercise this will bring us closer to understanding
>> the 'hang' in powervr userspace<->kernel interaction. Since it just
>> doesn't happen with old clutter and old hildon-desktop. So I am trying
>> to answer the question: what change in either clutter or hildon-desktop
>> would cause this?
>
> This part of work is already done by me a while ago. I guess I found the
> cause of the hang. The functions calls trace that leads to 2+ minutes hang
> on hildon-desktop startup is in attachment, see file "hildon-desktop".

That's useful info, thanks.

> I did a simple "monkey" patch to fix the hang. If you are interested,
> please check the second attachment "hang-fix.patch". Note: it's just
> quick and dirty workaround, not a real fix. And yes, it's for cogl.

Did we also switch to a newer cogl?

> If you guys really want to migrate to new clutter/cogl frameworks, I'd
> recommend to stop using deprecated functions.

That's always a good advice, do you think the deprecated function itself
is the problem here (for the hang) - I guess there is one way to find out.

In general, I think we should go for newer software. If the difference
in code and features between clutter 0.8 is not that big, and it's a
huge undertaking to figure out why it is so slow, we could consider
sticking with clutter 0.8 while we work on more important issues, but in
the end, we want to *reduce* our maintenance burden by using upstream
software.

Cheers,
Merlijn