[PATCH 3/3] gears: add a warning about refresh rate limitation

[Pekka Paalanen]

On Thu, 26 Jul 2012 18:55:53 +0200
Olivier Blin <olivier.blin at softathome.com> wrote:

> ---
>  clients/gears.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/clients/gears.c b/clients/gears.c
> index 19165e7..aee0357 100644
> --- a/clients/gears.c
> +++ b/clients/gears.c
> @@ -435,6 +435,7 @@ gears_create(struct display *display)
>  
>  	gettimeofday(&tv, NULL);
>  	gears->last_fps = tv.tv_sec * 1000 + tv.tv_usec / 1000;
> +	printf("Warning: FPS count is limited by the wayland compositor or monitor refresh rate\n");

Ok, that seems sufficient, thanks.

For a bonus, could you still explain what this FPS count actually
measures?

Something like this: it measures how often a very simple GL program
can show new content. This is limited by the monitors' refresh
rates, system load, compositor performance, and finally the
program's own performance.

"show new content" is a hint, that it does not measure rendering
speed nor "Wayland speed".

I wrote monitors in plural, because having the gears surface on
multiple monitors simultaneously might limit the FPS to the sum of
the individual refresh rates, depending a bit. I'm not sure how
Weston behaves currently.

Heh, that would be a nice headline: "Adding more monitors in clone
mode speeds up Wayland!" ;-)


Thanks,
pq