Slow app_server drawing with new scheduler

[jua]

With the new scheduler, I get very slow graphics drawing on my machine. Dragging windows around is slow and lagging, same with e.g. scrolling a website in WebPositive. Fluid video playback is impossible.

A good way to benchmark this is the "Chart" application from our Demos folder. I tested with 3 Haiku revisions:

• hrev46684 (nightly right before the scheduler merge)
• hrev46699 (nightly right after the scheduler merge)
• hrev46893 (latest nightly)

Selecting "DirectWindow" as display method in Chart, all three revisions get fluid 60fps with 3% CPU usage. However, using "DrawBitmap", the problem becomes apparent: only the pre-scheduler-merge version performs well and fluid, the others suffer from very bad performance (less than 10fps even at 100% CPU usage).

I'm attaching 3 screenshots of the test which also show ActivityMonitor.

Test system: AMD E-450 APU (dual core), Radeon HD6320, 2GB RAM. Same behaviour with both, radeon_hd and VESA graphics driver.

Let me know if further information is required.

[jua]

Running Chart on hrev46684 (old scheduler)

[jua]

Running Chart on hrev46699 (new scheduler)

[jua]

Running Chart on hrev46893 (new scheduler, latest)