2 * lib/smp_processor_id.c
4 * DEBUG_PREEMPT variant of smp_processor_id().
6 #include <linux/module.h>
7 #include <linux/kallsyms.h>
8 #include <linux/sched.h>
10 notrace unsigned int debug_smp_processor_id(void)
12 unsigned long preempt_count = preempt_count();
13 int this_cpu = raw_smp_processor_id();
15 if (likely(preempt_count))
22 * Kernel threads bound to a single CPU can safely use
25 if (cpumask_equal(¤t->cpus_allowed, cpumask_of(this_cpu)))
29 * It is valid to assume CPU-locality during early bootup:
31 if (system_state != SYSTEM_RUNNING)
37 preempt_disable_notrace();
39 if (!printk_ratelimit())
42 printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x] "
44 preempt_count() - 1, current->comm, current->pid);
45 print_symbol("caller is %s\n", (long)__builtin_return_address(0));
49 preempt_enable_no_resched_notrace();
54 EXPORT_SYMBOL(debug_smp_processor_id);