[PATCH] sched: Use macro for magic number of -1 for setparam

From: Steven Rostedt
Date: Wed Jul 23 2014 - 11:28:35 EST


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 <rostedt@xxxxxxxxxxx>
---
kernel/sched/core.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

Index: linux-trace.git/kernel/sched/core.c
===================================================================
--- linux-trace.git.orig/kernel/sched/core.c 2014-07-23 11:19:24.396368654 -0400
+++ linux-trace.git/kernel/sched/core.c 2014-07-23 11:27:30.013401767 -0400
@@ -3203,12 +3203,18 @@
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;
@@ -3557,11 +3563,8 @@
.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;
@@ -3731,7 +3734,7 @@
*/
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);
}

/**
--
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