sched/deadline: Fix rt runtime corruption when dl fails its global constraints

Wanpeng Li · Ingo Molnar · commit a1963b81deec · 2015-03-27T09:36:15.000+01:00
One version of sched_rt_global_constaints() (the !rt-cgroup one) changes state, therefore if we fail the later sched_dl_global_constraints() call the state is left in an inconsistent state. Fix this by changing the order of the calls. Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> [ Improved the changelog. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@arm.com> Link: http://lkml.kernel.org/r/1426590931-4639-2-git-send-email-wanpeng.li@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
@@ -7804,7 +7804,7 @@ static int sched_rt_global_constraints(void)
 }
 #endif /* CONFIG_RT_GROUP_SCHED */
 
-static int sched_dl_global_constraints(void)
+static int sched_dl_global_validate(void)
 {
 	u64 runtime = global_rt_runtime();
 	u64 period = global_rt_period();
@@ -7905,11 +7905,11 @@ int sched_rt_handler(struct ctl_table *table, int write,
 		if (ret)
 			goto undo;
 
-		ret = sched_rt_global_constraints();
+		ret = sched_dl_global_validate();
 		if (ret)
 			goto undo;
 
-		ret = sched_dl_global_constraints();
+		ret = sched_rt_global_constraints();
 		if (ret)
 			goto undo;
 
