sched: add PF_WAKE_UP_IDLE

Certain workloads may benefit from the SD_SHARE_PKG_RESOURCES behavior
of waking their tasks up on idle CPUs. The feature has too much of a
negative impact on other workloads however to apply globally. The
PF_WAKE_UP_IDLE flag tells the scheduler to wake up tasks that have this
flag set, or tasks woken by tasks with this flag set, on an idle CPU
if one is available.

Change-Id: I20b28faf35029f9395e9d9f5ddd57ce2de795039
Signed-off-by: Steve Muckle <smuckle@codeaurora.org>
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 5fb3719..2c9509d 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1819,6 +1819,7 @@
 #define PF_MEMALLOC	0x00000800	/* Allocating memory */
 #define PF_NPROC_EXCEEDED 0x00001000	/* set_user noticed that RLIMIT_NPROC was exceeded */
 #define PF_USED_MATH	0x00002000	/* if unset the fpu must be initialized before use */
+#define PF_WAKE_UP_IDLE 0x00004000	/* try to wake up on an idle CPU */
 #define PF_NOFREEZE	0x00008000	/* this thread should not be frozen */
 #define PF_FROZEN	0x00010000	/* frozen for system suspend */
 #define PF_FSTRANS	0x00020000	/* inside a filesystem transaction */
@@ -1936,6 +1937,14 @@
 }
 #endif
 
+static inline void set_wake_up_idle(bool enabled)
+{
+	if (enabled)
+		current->flags |= PF_WAKE_UP_IDLE;
+	else
+		current->flags &= ~PF_WAKE_UP_IDLE;
+}
+
 #ifndef CONFIG_CPUMASK_OFFSTACK
 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
 {