From 62ec05dd71b19f5be890a1992227cc7b2ac0adc4 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 24 May 2017 10:15:41 +0200 Subject: [PATCH] sched: Provide is_percpu_thread() helper Provide a helper function for checking whether current task is a per cpu thread. Signed-off-by: Thomas Gleixner Tested-by: Paul E. McKenney Acked-by: Ingo Molnar Cc: Peter Zijlstra Cc: Sebastian Siewior Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20170524081549.541649540@linutronix.de --- include/linux/sched.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/include/linux/sched.h b/include/linux/sched.h index 2b69fc650201..3dfa5f99d6ee 100644 --- 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 */ -- 2.20.1