Balbir Singh wrote: > On Fri, Jun 5, 2009 at 11:33 AM, Avi Kivity <avi@xxxxxxxxxx> wrote: > >> Bharata B Rao wrote: >> >>>> Another way is to place the 8 groups in a container group, and limit >>>> that to 80%. But that doesn't work if I want to provide guarantees to >>>> several groups. >>>> >>>> >>> Hmm why not ? Reduce the guarantee of the container group and provide >>> the same to additional groups ? >>> >>> >> This method produces suboptimal results: >> >> $ cgroup-limits 10 10 0 >> [50.0, 50.0, 40.0] >> >> I want to provide two 10% guaranteed groups and one best-effort group. >> Using the limits method, no group can now use more than 50% of the >> resources. However, having the first group use 90% of the resources does >> not violate any guarantees, but it not allowed by the solution. >> >> > > How, it works out fine in my calculation > > 50 + 40 for G2 and G3, make sure that G1 gets 10%, since others are > limited to 90% > 50 + 40 for G1 and G3, make sure that G2 gets 10%, since others are > limited to 90% > 50 + 50 for G1 and G2, make sure that G3 gets 0%, since others are > limited to 100% > It's fine in that it satisfies the guarantees, but it is deeply suboptimal. If I ran a cpu hog in the first group, while the other two were idle, it would be limited to 50% cpu. On the other hand, if it consumed all 100% cpu it would still satisfy the guarantees (as the other groups are idle). The result is that in such a situation, wall clock time would double even though cpu resources are available. > Now if we really have zeros, I would recommend using > > cgroup-limits 10 10 and you'll see that you'll get 90, 90 as output. > > Adding zeros to the calcuation is not recommended. Does that help? What do you mean, it is not recommended? I have two groups which need at least 10% and one which does not need any guarantee, how do I express it? In any case, changing the zero to 1% does not materially change the results. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain. _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
