sched: Use macro for magic number of -1 for setparam

Instead of passing around a magic number -1 for the sched_setparam() policy, use a more descriptive macro name like SETPARAM_POLICY. [ based on top of Daniel's sched_setparam() fix ] Signed-off-by: Steven Rostedt <[email protected]> Signed-off-by: Peter Zijlstra <[email protected]> Cc: Daniel Bristot de Oliveira<[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]>
Baughn · Jul 28, 2014 · c13db6b · c13db6b
1 parent 6ae72df
commit c13db6b
Showing 1 changed file with 10 additions and 7 deletions.
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
@@ -3218,12 +3218,18 @@ __setparam_dl(struct task_struct *p, const struct sched_attr *attr)
 	dl_se->dl_yielded = 0;
 }
 
+/*
+ * sched_setparam() passes in -1 for its policy, to let the functions
+ * it calls know not to change it.
+ */
+#define SETPARAM_POLICY	-1
+
 static void __setscheduler_params(struct task_struct *p,
 		const struct sched_attr *attr)
 {
 	int policy = attr->sched_policy;
 
-	if (policy == -1) /* setparam */
+	if (policy == SETPARAM_POLICY)
 		policy = p->policy;
 
 	p->policy = policy;
@@ -3572,11 +3578,8 @@ static int _sched_setscheduler(struct task_struct *p, int policy,
 		.sched_nice	= PRIO_TO_NICE(p->static_prio),
 	};
 
-	/*
-	 * Fixup the legacy SCHED_RESET_ON_FORK hack, except if
-	 * the policy=-1 was passed by sched_setparam().
-	 */
-	if ((policy != -1) && (policy & SCHED_RESET_ON_FORK)) {
+	/* Fixup the legacy SCHED_RESET_ON_FORK hack. */
+	if ((policy != SETPARAM_POLICY) && (policy & SCHED_RESET_ON_FORK)) {
 		attr.sched_flags |= SCHED_FLAG_RESET_ON_FORK;
 		policy &= ~SCHED_RESET_ON_FORK;
 		attr.sched_policy = policy;
@@ -3746,7 +3749,7 @@ SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy,
  */
 SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param)
 {
-	return do_sched_setscheduler(pid, -1, param);
+	return do_sched_setscheduler(pid, SETPARAM_POLICY, param);
 }
 
 /**