Messages in this thread Patch in this message | | | Date | Tue, 25 Apr 2017 17:52:17 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 4/4] sched/topology: the group balance cpu must be a cpu where the group is installed |
| |
On Tue, Apr 25, 2017 at 05:39:37PM +0200, Peter Zijlstra wrote: > On Tue, Apr 25, 2017 at 05:27:03PM +0200, Peter Zijlstra wrote:
> > Ah! the asymmetric setup, where @sibling is entirely uninitialized for > > the top domain.
Like so then...
--- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -509,6 +509,11 @@ static void build_group_mask(struct sche for_each_cpu(i, sg_span) { sibling = *per_cpu_ptr(sdd->sd, i); + /* + * Can happen in the asymmetric case, where these siblings are + * unused. The mask will not be empty because those CPUs that + * do have the top domain _should_ span the domain. + */ if (!sibling->child) continue; @@ -518,6 +523,9 @@ static void build_group_mask(struct sche cpumask_set_cpu(i, sched_group_mask(sg)); } + + /* We must not have empty masks here */ + WARN_ON_ONCE(cpumask_empty(sched_group_mask(sg))); } /*
| |