sched/topology: Propagate SMT flags when removing degenerate domain

When a degenerate cluster domain for core with SMT CPUs is removed,
the SD_SHARE_CPUCAPACITY flag in the local child sched group was not
propagated to the new parent.  We need this flag to properly determine
whether the local sched group is SMT.  Set the flag in the local
child sched group of the new parent sched domain.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Link: https://lkml.kernel.org/r/73cf0959eafa53c02e7ef6bf805d751d9190e55d.1683156492.git.tim.c.chen@linux.intel.com

diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 6682535e37c828af691ce7311351f9289a81f706..ca4472281c28652f7756f6c82f5bd5aba4a6f9e0 100644 (file)
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -719,8 +719,13 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu)
 
                if (sd_parent_degenerate(tmp, parent)) {
                        tmp->parent = parent->parent;
-                       if (parent->parent)
+
+                       if (parent->parent) {
                                parent->parent->child = tmp;
+                               if (tmp->flags & SD_SHARE_CPUCAPACITY)
+                                       parent->parent->groups->flags |= SD_SHARE_CPUCAPACITY;
+                       }
+
                        /*
                         * Transfer SD_PREFER_SIBLING down in case of a
                         * degenerate parent; the spans match for this