RIFS-ES Linux Kernel Scheduler Released

[HappyHoward]

What are the chances of this scheduler making it into the "main tree" or whatever its called? I saw earlier in this thread there is no support for pluggable schedulers. I guess CFS is better for raw throughput which seems more important in a server environment? Even if it doesn't make it into mainline, is there a chance distros aimed at desktops will patch their kernel to support this RIFS-ES scheduler?

Excuse my total ignorance in these matters...

[Naib]

Why is this dependant on CONFIG_HOTPLUG_CPU if you have CONFIG_SMP enabled.

[Paradox Ethereal]

Latency ++

The linuxkernel configged for desktop is perfectly fine. I`ve had it running reliably with 0.3ms audiostreams.

As I said in another thread:

Not everyone has the skill to config linux. If you do though, you can get latencies down to 0.3ms, and games will be smooth like asm-coded custom hardware arcades. And ofcourse you can put all kinds of modern gpu features on that. I did that with doom3 and I have never played anything as amazing. And that was even with X, and Wayland is going to be better.

If you are into windows though, which has more SOFTWARE, there is nothing wrong with linux as an OS, then try disabling all the drivers you can. That will reduce latency on windows. And you will have a similar experience. Not as low latency, but close enough to atleast match Amiga 500, which for many is a benchmark of responsiveness. (some crackle at 1.5ms latency). Also windows has some really old drivers for instance, if you run XP which many say has the lowest latency. Try to get updated drivers.

And mac is typically better for professional work, software wise. 1.5ms latency unproblematic, but games doesn`t seem to run that well, yet, or maybe there is some option I haven`t seen yet. (turning off 3d-desktop?)

Peace Be With You.

And you do not need the RT-kernel anymore for that.

And I did not notice any performance loss with tickless on.

I didn`t bother reading all the pages, just up to 7.

An optimal lowlatency scheduler, would ofcourse be focused on latency, but not to the point of using unreasonable resources.

And it should have the prioritized task and it`s depencies favoured for most cpu, and setting aside a tiny bit of cpu, for background tasks, so little it won`t be noticable. Just for small things.

Resource use, and background tasks, should have variables, to tweak in realtime, probably based on uS.
Something like I don`t know:
Slice time, the resolution of scheduling. (uS)
And then how much of that slice goes to prioritized app & depencies (99.99%?), and the rest to background tasks.

Couldn`t you really simplify it down to that?

Peace Be With You.

[Naib]

Well I tried it (again) with 3.5.3 ... Got GPS drop in HoN and irratic GPS while without this a constant 60fps.

Still say it is bad

[3766691]

Well I tried it (again) with 3.5.3 ... Got GPS drop in HoN and irratic GPS while without this a constant 60fps.

Still say it is bad

With ES mode enabled or not?

[Naib]

didn't try ES, could try again tonight


--edit--
bugger just noticed a typo from the prev post. That should be FPS not GPS... damn autocorrect...

[3766691]

didn't try ES, could try again tonight


--edit--
bugger just noticed a typo from the prev post. That should be FPS not GPS... damn autocorrect...

You can try it by 'echo 1 > /proc/sys/kernel/sched_rifs/es_mode' without recompiling the kernel.

[3766691]

success

I have posted the temp. tickless hotfix for RIFS. After few days I will merge it into the offical patch.

[Naib]

I tried that echo 1 ... fps still irratic (maybe more so) going from 55 downto 45 (at a couple of point downto 12)...

I'm sure this scheduler and the logical reasoning behind it is sound, its just not universally good. Im switching back to BFS or vanilla. I have tried this a couple of times and its just not suitable for gaming

[3766691]

Seems that there is no significant performance lost with tickless enabled.