Op Saturday 17 March 2007, schreef Ingo Molnar: > * jos poortvliet <[EMAIL PROTECTED]> wrote: > > Op Saturday 17 March 2007, schreef Ingo Molnar: > > > so it is not at all clear to me that RSDL is indeed an improvement, > > > if it does not have comparable auto-nice properties. > > > > Wasn't the point of RSDL to get rid of the auto-nice, because it > > caused starvation, unpredictable behaviour and other problems? > > it doesnt really get rid of it, it replaces it with another mechanism > that is fundamentally unfair too. > > RSDL has _another_, albeit more hidden "auto-nice" behavior: this time > expressed not via the plain manipulation of priorities based on the > sleep average, but expressed via the quota-depletion flux of tasks over > time, fed into a complex dance of rotating priorities - which > quota-depletion flux is in essence a sleep average too, just more > derived and more hardcoded.
Hmmm. I wonder, then, does RSDL give an advantage in the areas I mentioned (starvation and predictability)? RSDL does give equal timeslices (eg equal cpu time) to each process - it's just that processes which didn't use their time yet can quickly run, right? Now I might not understand things here, but that it sounds more fair, though you're more quallified to judge that. So, for me, as an user, it boils down to: does this solve problems, and does it introduce problems? I must say I compare RSDL to staircase, as that's what I'm used to - a bit more interactive compared to mainline. RSDL does slightly worse AND slightly better - worse in interactivity on heavy loads (8 makes running on my dualcore) but it doesn't have the systemwide stalls sometimes occurring on both mainline and staircase - though it replaces them with shorter, app-specific ones (the worse interactivity I mention). > or looking at it from another angle, code size: > > text data bss dec hex filename > 15750 24 6008 21782 5516 sched.o.vanilla > 15960 360 6336 22656 5880 sched.o.rsdl > > there's no reduction in complexity, it just moved elsewhere. > > Ingo -- Disclaimer: Alles wat ik doe denk en zeg is gebaseerd op het wereldbeeld wat ik nu heb. Ik ben niet verantwoordelijk voor wijzigingen van de wereld, of het beeld wat ik daarvan heb, noch voor de daaruit voortvloeiende gedragingen van mezelf. Alles wat ik zeg is aardig bedoeld, tenzij expliciet vermeld.
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