On Mon, Aug 24, 2015 at 2:17 PM, Tejun Heo <tj@xxxxxxxxxx> wrote: > Hello, > > On Mon, Aug 24, 2015 at 02:10:17PM -0700, Paul Turner wrote: >> Suppose that we have 10 vcpu threads and 100 support threads. >> Suppose that we want the support threads to receive up to 10% of the >> time available to the VM as a whole on that machine. >> >> If I have one particular support thread that is busy, I want it to >> receive that entire 10% (maybe a guest is pounding on scsi for >> example, or in the thread-pool case, I've passed a single expensive >> computation). Conversely, suppose the guest is doing lots of >> different things and several support threads are active, I want the >> time to be shared between them. >> >> There is no way to implement this with nice. Either a single thread >> can consume 10%, and the group can dominate, or the group cannot >> dominate and the single thread can be starved. > > Would it be possible for you to give realistic and concrete examples? > I'm not trying to play down the use cases but concrete examples are > usually helpful at putting things in perspective. I don't think there's anything that's not realistic or concrete about the example above. The "suppose" parts were only for qualifying the pool sizes for vcpu and non-vcpu threads above since discussion of implementation using nice is dependent on knowing these counts. > > Thanks. > > -- > tejun -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
