From: Ran Xiaokai <ran.xiaokai@zte.com.cn>
steps to reproduce this issue:
on a 8 cpu system:
1. starting kernel using "isolcpus=domain,4-7" cmdline
2. offline all the housekeeping cpu. [0-3]
now ndoms_cur = 1 and doms_cur[0] will be with a empty cpumask.
3. offline anyone of the non-housekeeping cpu.
kernel panic whth:
Unable to handle kernel paging request at virtual address ffff80001128e9a1
Call trace:
partition_sched_domains_locked+0x294/0x348
rebuild_sched_domains_locked+0x3e4/0x750
rebuild_sched_domains+0x2c/0x48
cpuset_hotplug_workfn+0x45c/0x800
process_one_work+0x1c4/0x498
worker_thread+0x50/0x420
kthread+0x114/0x150
Code: 9413028b f94037e1 f8605820 8b170017 (f944d2e0)
---[ end trace 81aa4bc5dcb7a4d5 ]---
Kernel panic - not syncing: Fatal exception
fix this whit a non-empty check with doms_cur[i]
Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
---
kernel/sched/topology.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 05b6c2a..4fa9bdf 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -2558,16 +2558,18 @@ void partition_sched_domains_locked(int ndoms_new, cpumask_var_t doms_new[],
for (j = 0; j < n && !new_topology; j++) {
if (cpumask_equal(doms_cur[i], doms_new[j]) &&
dattrs_equal(dattr_cur, i, dattr_new, j)) {
- struct root_domain *rd;
-
- /*
- * This domain won't be destroyed and as such
- * its dl_bw->total_bw needs to be cleared. It
- * will be recomputed in function
- * update_tasks_root_domain().
- */
- rd = cpu_rq(cpumask_any(doms_cur[i]))->rd;
- dl_clear_root_domain(rd);
+ if (!cpumask_empty(doms_cur[i])) {
+ struct root_domain *rd;
+
+ /*
+ * This domain won't be destroyed and as such
+ * its dl_bw->total_bw needs to be cleared. It
+ * will be recomputed in function
+ * update_tasks_root_domain().
+ */
+ rd = cpu_rq(cpumask_any(doms_cur[i]))->rd;
+ dl_clear_root_domain(rd);
+ }
goto match1;
}
}
--
2.15.2