sched: add missing arch_update_cpu_topology() call

arch_reinit_sched_domains() used to call arch_update_cpu_topology()
via arch_init_sched_domains(). This call got lost with
e761b7725234276a802322549cee5255305a0930 ("cpu hotplug, sched: Introduce
cpu_active_map and redo sched domain managment (take 2)".

So we might end up with outdated and missing cpus in the cpu core
maps (architecture used to call arch_reinit_sched_domains if cpu
topology changed).

This adds a call to arch_update_cpu_topology in partition_sched_domains
which gets called whenever scheduling domains get updated. Which is
what is supposed to happen when cpu topology changes.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/kernel/sched.c b/kernel/sched.c
index fcfbbd9dbd6083f677facab260c2395dfe46485f..ad7b93be56918e9137c60c79f171d38c44608819 100644 (file)
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -7774,17 +7774,21 @@ void partition_sched_domains(int ndoms_new, cpumask_t *doms_new,
                             struct sched_domain_attr *dattr_new)
 {
        int i, j, n;
+       int new_topology;
 
        mutex_lock(&sched_domains_mutex);
 
        /* always unregister in case we don't destroy any domains */
        unregister_sched_domain_sysctl();
 
+       /* Let architecture update cpu core mappings. */
+       new_topology = arch_update_cpu_topology();
+
        n = doms_new ? ndoms_new : 0;
 
        /* Destroy deleted domains */
        for (i = 0; i < ndoms_cur; i++) {
-               for (j = 0; j < n; j++) {
+               for (j = 0; j < n && !new_topology; j++) {
                        if (cpus_equal(doms_cur[i], doms_new[j])
                            && dattrs_equal(dattr_cur, i, dattr_new, j))
                                goto match1;
@@ -7804,7 +7808,7 @@ match1:
 
        /* Build new domains */
        for (i = 0; i < ndoms_new; i++) {
-               for (j = 0; j < ndoms_cur; j++) {
+               for (j = 0; j < ndoms_cur && !new_topology; j++) {
                        if (cpus_equal(doms_new[i], doms_cur[j])
                            && dattrs_equal(dattr_new, i, dattr_cur, j))
                                goto match2;