cpuset: re-structure update_cpumask() a bit
Check if cpus_allowed is to be changed before calling validate_change().
This won't change any behavior, but later it will allow us to do this:
# mkdir /cpuset/child
# echo $$ > /cpuset/child/tasks /* empty cpuset */
# echo > /cpuset/child/cpuset.cpus /* do nothing, won't fail */
Without this patch, the last operation will fail.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 51f8e1d..535dce6 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -856,14 +856,15 @@
if (!cpumask_subset(trialcs->cpus_allowed, cpu_active_mask))
return -EINVAL;
}
- retval = validate_change(cs, trialcs);
- if (retval < 0)
- return retval;
/* Nothing to do if the cpus didn't change */
if (cpumask_equal(cs->cpus_allowed, trialcs->cpus_allowed))
return 0;
+ retval = validate_change(cs, trialcs);
+ if (retval < 0)
+ return retval;
+
retval = heap_init(&heap, PAGE_SIZE, GFP_KERNEL, NULL);
if (retval)
return retval;