diff options
Diffstat (limited to 'kernel/sched/topology.c')
| -rw-r--r-- | kernel/sched/topology.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c index 90f3e5558fa2..b296c1c6b961 100644 --- a/kernel/sched/topology.c +++ b/kernel/sched/topology.c @@ -675,6 +675,7 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) { struct rq *rq = cpu_rq(cpu); struct sched_domain *tmp; + int numa_distance = 0; /* Remove the sched domains which do not contribute to scheduling. */ for (tmp = sd; tmp; ) { @@ -706,6 +707,38 @@ cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) sd->child = NULL; } + for (tmp = sd; tmp; tmp = tmp->parent) + numa_distance += !!(tmp->flags & SD_NUMA); + + /* + * FIXME: Diameter >=3 is misrepresented. + * + * Smallest diameter=3 topology is: + * + * node 0 1 2 3 + * 0: 10 20 30 40 + * 1: 20 10 20 30 + * 2: 30 20 10 20 + * 3: 40 30 20 10 + * + * 0 --- 1 --- 2 --- 3 + * + * NUMA-3 0-3 N/A N/A 0-3 + * groups: {0-2},{1-3} {1-3},{0-2} + * + * NUMA-2 0-2 0-3 0-3 1-3 + * groups: {0-1},{1-3} {0-2},{2-3} {1-3},{0-1} {2-3},{0-2} + * + * NUMA-1 0-1 0-2 1-3 2-3 + * groups: {0},{1} {1},{2},{0} {2},{3},{1} {3},{2} + * + * NUMA-0 0 1 2 3 + * + * The NUMA-2 groups for nodes 0 and 3 are obviously buggered, as the + * group span isn't a subset of the domain span. + */ + WARN_ONCE(numa_distance > 2, "Shortest NUMA path spans too many nodes\n"); + sched_domain_debug(sd, cpu); rq_attach_root(rq, rd); |