On Thu, Jul 27, 2006 at 02:32:45PM +0200, Wilhelm Meier wrote: > Am Donnerstag, 27. Juli 2006 13:20 schrieb Herbert Poetzl: > > On Thu, Jul 27, 2006 at 09:50:37AM +0200, Wilhelm Meier wrote: > > > Am Mittwoch, 26. Juli 2006 22:04 schrieb Herbert Poetzl: > > > > > > well, not all solaris does is a good idea per se > > > > > > and I think the current hard cpu scheduler is much > > > > > > more powerful than the solaris proportional stuff > > > > > > (i.e. you can consider the solaris settings a subset > > > > > > of what you can achieve with the hard cpu scheduler) > > > > > > > > > > If the solaris fss is a subset, how do I set the token > > > > > bucket values? With 3 vservers and 0.5 , 0.25 , 0.25 as > > > > > (fillrate/intervall) for these, how do I get 2/3 for the first > > > > > and 1/3 for the second vserver if the third vserver is idle as > > > > > in the solaris fss case? Where is the hidden parameter? > > > > > > > > I take it that you 'simply' want fair scheduling > > > > between three guests in a 2:1:1 ratio when all three > > > > guests are hogging cpu, yes? > > > > > > Yes, the above settings of (fillrate/intervall) should achieve this. > > > > > > > in this case you simply forget the maximum values > > > > i.e. set them to something very low to give some > > > > kind of minimum amount of tokens per time unit, e.g. > > > > 1/100 and use a set of 2:1:1 for the idle time values > > > > e.g. 1/3,1/6 and 1/6. once hard cpu and indle time > > > > is enabled for those guests, they will run in the > > > > specified ratio, as long as host processes do not > > > > consume cpu resources, in which case the remaining > > > > cpu resources will be divided 2:1:1 between them > > > > > > But what happens if the third vserver falls to idle? > > > > > > In the solaris case the remaining two vservers would get 2/3 and > > > 1/3 of the cpus (if the host ifself is idle as well). > > > > same here as there a 2/6 added for each idle time tick to > > the first guest and 1/6 for the second one, which still > > is 2:1 as in your 2/3 and 1/3 example ... > > > > > In the vserver case we get idle time now: 1/4 with the values above. > > > > how do you come to this conclusion? > > I try to summarize: we have three vservers with 1/2, 1/4, 1/4 as > values for (fillrate/intervall)_1 (not idle time). > > If all three vservers have runnable processes, they get 1/2, 1/4, 1/4 > of a cpu (if we have more than one cpu we scale the values to sum up > to the number of cpus). > > If the third vserver now gets idle, the first and second vserver still > gets 1/2 and 1/4 of a cpu (if they have tokensmax in the bucket, they > can get more of a cpu for a limited burst-time). In the long run there > is 1/4 of a cpu idle. > > If we have setup the idle time bucket and the three vservers have > the (fillrate/intervall)_2 values 1/2, 1/4, 1/4 for this also, the > remaining 1/4 of the cpu (which is left idle from the normal tocken > bucket) is given to the vservers. > > If the third vserver is still idle, the first vserver gets 1/4 * 1/2 > from the idle token bucket and this sums to 1/2 + 1/8 = 5/8. The > second vserver sums up to 1/4 + 1/4*1/4 = 5/16. > > So the ratio between the first and second vserver is still 2:1. But > we left 1/16 of a cpu idle. And this leds to a recursion and then the > two active vservers gets 2/3 and 1/3 of a cpu. Yes, I think I got it > ;-)
> Thank you! you're welcome! > Is this type of scheduler already in the stable version? it is in the _very stable_ development branch :) HTH, Herbert > ... > > > > as usual, all the features are supported by my 'hack' tools > > in various forms, this one is probably best to control with > > the vsched (0.02) or the vcmd tool (which is non trivial to > > use, I guess), but it would definitely be better to get this > > functionality into mainline userspace tools ... > > > > http://vserver.13thfloor.at/Experimental/TOOLS/ > > Thank you for the hint! > > -- > Wilhelm _______________________________________________ Vserver mailing list Vserver@list.linux-vserver.org http://list.linux-vserver.org/mailman/listinfo/vserver
