git://bbs.cooldavid.org / net-next-2.6.git / blame
| Commit | Line | Data |
|---|---|---|
| 39c715b7 IM |
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 | ||
| 9 | unsigned int debug_smp_processor_id(void) | |
| 10 | { | |
| 11 | unsigned long preempt_count = preempt_count(); | |
| 12 | int this_cpu = raw_smp_processor_id(); | |
| 13 | cpumask_t this_mask; | |
| 14 | ||
| 15 | if (likely(preempt_count)) | |
| 16 | goto out; | |
| 17 | ||
| 18 | if (irqs_disabled()) | |
| 19 | goto out; | |
| 20 | ||
| 21 | /* | |
| 22 | * Kernel threads bound to a single CPU can safely use | |
| 23 | * smp_processor_id(): | |
| 24 | */ | |
| 25 | this_mask = cpumask_of_cpu(this_cpu); | |
| 26 | ||
| 27 | if (cpus_equal(current->cpus_allowed, this_mask)) | |
| 28 | goto out; | |
| 29 | ||
| 30 | /* | |
| 31 | * It is valid to assume CPU-locality during early bootup: | |
| 32 | */ | |
| 33 | if (system_state != SYSTEM_RUNNING) | |
| 34 | goto out; | |
| 35 | ||
| 36 | /* | |
| 37 | * Avoid recursion: | |
| 38 | */ | |
| 39 | preempt_disable(); | |
| 40 | ||
| 41 | if (!printk_ratelimit()) | |
| 42 | goto out_enable; | |
| 43 | ||
| 44 | printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x] code: %s/%d\n", preempt_count(), current->comm, current->pid); | |
| 45 | print_symbol("caller is %s\n", (long)__builtin_return_address(0)); | |
| 46 | dump_stack(); | |
| 47 | ||
| 48 | out_enable: | |
| 49 | preempt_enable_no_resched(); | |
| 50 | out: | |
| 51 | return this_cpu; | |
| 52 | } | |
| 53 | ||
| 54 | EXPORT_SYMBOL(debug_smp_processor_id); | |
| 55 |