Re: [Xen-devel] [PATCH] xen: cpupool: forbid to split cores among different pools

2018-08-21 Thread Dario Faggioli
On Tue, 2018-08-21 at 10:25 +0200, Juergen Gross wrote: > On 20/08/18 18:43, Dario Faggioli wrote: > > > > Therefore, let's start allowing in a cpupool only cpus that have > > their > > SMT siblings, either: > > - in that same pool, > > - outside of any pool. > > Can we make this optional

Re: [Xen-devel] [PATCH] xen: cpupool: forbid to split cores among different pools

2018-08-21 Thread Juergen Gross
On 20/08/18 18:43, Dario Faggioli wrote: > On a system with hyperthreading, we currently allow putting cpus that > are SMT siblings in different cpupools. This is bad for a number of > reasons. > > For instance, the schedulers can't know whether or not a core is fully > idle or not, if the

[Xen-devel] [PATCH] xen: cpupool: forbid to split cores among different pools

2018-08-20 Thread Dario Faggioli
On a system with hyperthreading, we currently allow putting cpus that are SMT siblings in different cpupools. This is bad for a number of reasons. For instance, the schedulers can't know whether or not a core is fully idle or not, if the threads of such core are in different pools. This right now