ia64/linux-2.6.18-xen.hg

view lib/smp_processor_id.c @ 782:9ab1c319531f

merge with linux-2.6.18-xen.hg
author Isaku Yamahata <yamahata@valinux.co.jp>
date Wed Jan 28 13:07:23 2009 +0900 (2009-01-28)
parents 831230e53067
children
line source
1 /*
2 * lib/smp_processor_id.c
3 *
4 * DEBUG_PREEMPT variant of smp_processor_id().
5 */
6 #include <linux/module.h>
7 #include <linux/kallsyms.h>
8 #include <linux/sched.h>
10 unsigned int debug_smp_processor_id(void)
11 {
12 unsigned long preempt_count = preempt_count();
13 int this_cpu = raw_smp_processor_id();
14 cpumask_t this_mask;
16 if (likely(preempt_count))
17 goto out;
19 if (irqs_disabled())
20 goto out;
22 /*
23 * Kernel threads bound to a single CPU can safely use
24 * smp_processor_id():
25 */
26 this_mask = cpumask_of_cpu(this_cpu);
28 if (cpus_equal(current->cpus_allowed, this_mask))
29 goto out;
31 /*
32 * It is valid to assume CPU-locality during early bootup:
33 */
34 if (system_state != SYSTEM_RUNNING)
35 goto out;
37 /*
38 * Avoid recursion:
39 */
40 preempt_disable();
42 if (!printk_ratelimit())
43 goto out_enable;
45 printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x] code: %s/%d\n", preempt_count(), current->comm, current->pid);
46 print_symbol("caller is %s\n", (long)__builtin_return_address(0));
47 dump_stack();
49 out_enable:
50 preempt_enable_no_resched();
51 out:
52 return this_cpu;
53 }
55 EXPORT_SYMBOL(debug_smp_processor_id);