Main > Linux
Linux Kernel optimized configuration for emulation
philenotfound:
I build my own kernel because I had problems in the past with the Debian one which used CONFIG_PREEMPT_VOLUNTARY.
When playing Cho Ren Sha on X68000 with MAME I had some slowdowns which were acustically noticable (sound pitching...)
I build my own now with CONFIG_PREEMPT.
I'm wondering if a RT-Kernel can improve on those emulation-specific latencies.
Doozer:
--- Quote from: philenotfound on January 21, 2016, 12:43:57 am ---I build my own kernel because I had problems in the past with the Debian one which used CONFIG_PREEMPT_VOLUNTARY.
When playing Cho Ren Sha on X68000 with MAME I had some slowdowns which were acustically noticable (sound pitching...)
I build my own now with CONFIG_PREEMPT.
I'm wondering if a RT-Kernel can improve on those emulation-specific latencies.
--- End quote ---
I agree with you, the preemption must be configured like this:
--- Code: ---# CONFIG_PREEMPT_NONE is not set
# CONFIG_PREEMPT_VOLUNTARY is not set
CONFIG_PREEMPT=y
--- End code ---
Another thing, if you have fast responsive HID devices (1000Hz compliant) you can set this into the kernal as well.
--- Code: ---CONFIG_NO_HZ_COMMON=y
# CONFIG_HZ_PERIODIC is not set
CONFIG_NO_HZ_IDLE=y
# CONFIG_NO_HZ_FULL is not set
# CONFIG_NO_HZ is not set
# CONFIG_HZ_100 is not set
# CONFIG_HZ_250 is not set
# CONFIG_HZ_300 is not set
CONFIG_HZ_1000=y
CONFIG_HZ=1000
--- End code ---
Switching to a RT kernel will improve the latencies but the gain is negligible. The current timing requirement does not require RT aspect. The main drawback is coming from the latencies introduced by the graphical, input and audio libraries.
If you have a recent SDL library you can enable the wayland driver. Avoiding the unnecessary X11 layers could give better system response.
--- Code: ----videodriver wayland
--- End code ---