Eivind Nicolay Evensen
2018-Apr-17 06:56 UTC
kern.sched.quantum: Creepy, sadistic scheduler
On Wed, Apr 04, 2018 at 09:32:58AM -0400, George Mitchell wrote:> On 04/04/18 06:39, Alban Hertroys wrote: > > [...] > > That said, SCHED_ULE (the default scheduler for quite a while now) was designed with multi-CPU configurations in mind and there are claims that SCHED_4BSD works better for single-CPU configurations. You may give that a try, if you're not already on SCHED_4BSD. > > [...] > > A small, disgruntled community of FreeBSD users who have never seen > proof that SCHED_ULE is better than SCHED_4BSD in any environment > continue to regularly recompile with SCHED_4BSD. I dread the day when > that becomes impossible, but at least it isn't here yet. -- GeorgeIndeed 4bsd is better in my case aswell. While for some unknown to me reason ule performed a bit better in the 10.x series than before, in 11.x it again is in my case not usable. Mouse freezes for around half a second with even frequency by just moving it around in x11. Using 4bsd instead makes the problem go away. I'm actually very happy that ule became worse again because going back to 4bsd yet again also gave improved performance from other dreadfully slow but (to me) still useful programs, like darktable. With 4bsd, when adjusting shadows and highlights it is possible to see what I do when moving sliders. With ule it has never been better than waiting 10-20-30 seconds to see where it was able to read a slider position and update display, when working on images around 10500x10500 greyscale. It's not single cpu/single core either: CPU: AMD FX(tm)-6300 Six-Core Processor (3817.45-MHz K8-class CPU) -- Eivind
On Mon, Apr 16, 2018 at 11:56 PM, Eivind Nicolay Evensen < eivinde at terraplane.org> wrote:> On Wed, Apr 04, 2018 at 09:32:58AM -0400, George Mitchell wrote: > > On 04/04/18 06:39, Alban Hertroys wrote: > > > [...] > > > That said, SCHED_ULE (the default scheduler for quite a while now) was > designed with multi-CPU configurations in mind and there are claims that > SCHED_4BSD works better for single-CPU configurations. You may give that a > try, if you're not already on SCHED_4BSD. > > > [...] > > > > A small, disgruntled community of FreeBSD users who have never seen > > proof that SCHED_ULE is better than SCHED_4BSD in any environment > > continue to regularly recompile with SCHED_4BSD. I dread the day when > > that becomes impossible, but at least it isn't here yet. -- George > > Indeed 4bsd is better in my case aswell. While for some unknown to me > reason > ule performed a bit better in the 10.x series than before, in 11.x > it again is in my case not usable. > > Mouse freezes for around half a second with even frequency by just moving > it around in x11. Using 4bsd instead makes the problem go away. > I'm actually very happy that ule became worse again because going > back to 4bsd yet again also gave improved performance from other > dreadfully slow but (to me) still useful programs, like darktable. > > With 4bsd, when adjusting shadows and highlights it is possible to see > what I > do when moving sliders. With ule it has never been better than waiting > 10-20-30 seconds to see where it was able to read a slider position > and update display, when working on images around 10500x10500 greyscale. > > It's not single cpu/single core either: > CPU: AMD FX(tm)-6300 Six-Core Processor (3817.45-MHz K8-class > CPU) > > > > > -- > Eivind >My experience has long been that 4BSD works far better for interactive, X based systems than ULE. Even on 10 I saw long, annoying pauses with ULE and I don't se those with 4BSD. I'd really like to see it better known that this is often the case. BTW, my system is 2 core/4 thread Sandybridge. -- Kevin Oberman, Part time kid herder and retired Network Engineer E-mail: rkoberman at gmail.com PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683