[patch V3 30/32] sched: Provide is_percpu_thread() helper

From: Thomas Gleixner
Date: Wed May 24 2017 - 04:35:25 EST


Provide a helper function for checking whether current task is a per cpu
thread.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
include/linux/sched.h | 10 ++++++++++
1 file changed, 10 insertions(+)

--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1265,6 +1265,16 @@ extern struct pid *cad_pid;
#define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
#define used_math() tsk_used_math(current)

+static inline bool is_percpu_thread(void)
+{
+#ifdef CONFIG_SMP
+ return (current->flags & PF_NO_SETAFFINITY) &&
+ (current->nr_cpus_allowed == 1);
+#else
+ return true;
+#endif
+}
+
/* Per-process atomic flags. */
#define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
#define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */