gst_vaapi_texture_glx_put_surface_unlocked is blocked 75-80% of the time

Submitted by Daniel van Vugt @vanvugt

Link to original bug (#795195)

Description

gst_vaapi_texture_glx_put_surface_unlocked is blocked 75-80% of the time.

This means if you need more than 20-25% CPU to decode and render a video, you're going to miss frames.

I noticed this with two different machines. While they both spend around 75% of their (real) time blocked in gst_vaapi_texture_glx_put_surface_unlocked, only the one with the lower CPU requirement (10%) was able to render the video smoothly. The other machine which requires 40% CPU time to play the same video stutters badly, probably because 40%+75% > 100%.

Version: 1.14.0