What scheduler produces the best results on regular desktop systems?
mar., 2 mai 2023, 09:54 Holger Hoffstätte a
scris:
> On 2023-05-01 22:24, Nikos Chantziaras wrote:
> > On 26/04/2023 23:06, Holger Hoffstätte wrote:
> >> On 2023-04-26 18:15, Nikos Chantziaras wrote:
> >>> So I wanted to try the BMQ scheduler in gentoo-sources. Is just
> >>> enabling it in the kernel build all that's needed? I did so,
> >>> booted, and:
> >>>
> >>> $ dmesg | grep -i bmq [0.100284] sched/bmq: BMQ CPU Scheduler
> >>> v6.1-r4 by Alfred Chen.
> >>>
> >>> That's all and it's in use now? Or do I need to toggle anything
> >>> else?
> >>
> >> That's all you need to do, right. You can slso alternatively switch
> >> to PDS under the "General setup > Scheduler features" kernel-config
> >> menu, which is slightly better for throughput and "more correct"
> >> when many tasks have varying priorities - beefy workstation or
> >> server. BMQ is kind of simplistic (in an elegant way), but that's
> >> why it is so effective for low-end systems and desktops. Run iperf3
> >> over loopback (i.e. both server and client) to see the difference.
> >
> > Switched back to the default (called "CFS" I think.)
> >
> > BMQ has severe issues. When emerging something while I play a game
> > (either native or through wine-proton,) there's long lag spikes and
> > freezes. Even worse, there's bugs like the system completely hanging
> > on shutdown, or "umount" hanging with 100% CPU use by two kernel
> > threads.
>
> Can you try booting with psi=0 and check if that helps? There's a known
> bad interaction with the PSI (Pressure Stall Information) mechanism,
> which is active by default in many kernel configs. The latest version
> of the BMQ patch makes sure to turn it off, you may not have that version
> yet. BMQ (and PDS) works fine and has done so for quite a while.
>
> -h
>
>
