Re: [Xen-devel] [PATCH v2 1/2] xen: credit1: fix a race when picking initial pCPU for a vCPU

2016-08-19 Thread Dario Faggioli
On Fri, 2016-08-19 at 13:23 +0100, George Dunlap wrote: > On 18/08/16 11:00, Dario Faggioli wrote: > > @@ -248,6 +245,33 @@ __runq_elem(struct list_head *elem) > >  return list_entry(elem, struct csched_vcpu, runq_elem); > >  } > >   > > +/* Is the first element of cpu's runq (if any) cpu's

Re: [Xen-devel] [PATCH v2 1/2] xen: credit1: fix a race when picking initial pCPU for a vCPU

2016-08-19 Thread George Dunlap
On 18/08/16 11:00, Dario Faggioli wrote: > In the Credit1 hunk of 9f358ddd69463 ("xen: Have > schedulers revise initial placement") csched_cpu_pick() > is called without taking the runqueue lock of the > (temporary) pCPU that the vCPU has been assigned to > (e.g., in XEN_DOMCTL_max_vcpus). > >

[Xen-devel] [PATCH v2 1/2] xen: credit1: fix a race when picking initial pCPU for a vCPU

2016-08-18 Thread Dario Faggioli
In the Credit1 hunk of 9f358ddd69463 ("xen: Have schedulers revise initial placement") csched_cpu_pick() is called without taking the runqueue lock of the (temporary) pCPU that the vCPU has been assigned to (e.g., in XEN_DOMCTL_max_vcpus). However, although 'hidden' in the IS_RUNQ_IDLE() macro,