[Xen-devel] [PATCH v2 2/2] xen: credit1: avoid boosting vCPUs being "just" migrated

2016-02-12 Thread Dario Faggioli
Moving a vCPU to a different pCPU means offlining it and then waking it up, on the new pCPU. Credit1 grants BOOST priority to vCPUs that wakes up, with the aim of improving I/O latency. The net effect of this all is that vCPUs get boosted when migrating, which shouldn't happen. For instance, this

Re: [Xen-devel] [PATCH v2 2/2] xen: credit1: avoid boosting vCPUs being "just" migrated

2016-02-12 Thread Jan Beulich
>>> On 12.02.16 at 10:37, wrote: > @@ -787,6 +788,16 @@ _csched_cpu_pick(const struct scheduler *ops, struct > vcpu *vc, bool_t commit) > static int > csched_cpu_pick(const struct scheduler *ops, struct vcpu *vc) > { > +struct csched_vcpu *svc = CSCHED_VCPU(vc);

Re: [Xen-devel] [PATCH v2 2/2] xen: credit1: avoid boosting vCPUs being "just" migrated

2016-02-12 Thread Dario Faggioli
On Fri, 2016-02-12 at 02:50 -0700, Jan Beulich wrote: > > > > On 12.02.16 at 10:37, wrote: > > @@ -787,6 +788,16 @@ _csched_cpu_pick(const struct scheduler *ops, > > struct vcpu *vc, bool_t commit) > >  static int > >  csched_cpu_pick(const struct scheduler *ops, struct

Re: [Xen-devel] [PATCH v2 2/2] xen: credit1: avoid boosting vCPUs being "just" migrated

2016-02-12 Thread Dario Faggioli
[Yes, replying to myself] On Fri, 2016-02-12 at 11:50 +0100, Dario Faggioli wrote: > On Fri, 2016-02-12 at 02:50 -0700, Jan Beulich wrote: > > > > > On 12.02.16 at 10:37, wrote: > > > @@ -787,6 +788,16 @@ _csched_cpu_pick(const struct scheduler > > > *ops, > > > struct