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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /lib/smp_processor_id.c
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'lib/smp_processor_id.c')
-rw-r--r--lib/smp_processor_id.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/lib/smp_processor_id.c b/lib/smp_processor_id.c
new file mode 100644
index 00000000..4c0d0e51
--- /dev/null
+++ b/lib/smp_processor_id.c
@@ -0,0 +1,55 @@
+/*
+ * lib/smp_processor_id.c
+ *
+ * DEBUG_PREEMPT variant of smp_processor_id().
+ */
+#include <linux/export.h>
+#include <linux/kallsyms.h>
+#include <linux/sched.h>
+
+notrace unsigned int debug_smp_processor_id(void)
+{
+ unsigned long preempt_count = preempt_count();
+ int this_cpu = raw_smp_processor_id();
+
+ if (likely(preempt_count))
+ goto out;
+
+ if (irqs_disabled())
+ goto out;
+
+ /*
+ * Kernel threads bound to a single CPU can safely use
+ * smp_processor_id():
+ */
+ if (cpumask_equal(tsk_cpus_allowed(current), cpumask_of(this_cpu)))
+ goto out;
+
+ /*
+ * It is valid to assume CPU-locality during early bootup:
+ */
+ if (system_state != SYSTEM_RUNNING)
+ goto out;
+
+ /*
+ * Avoid recursion:
+ */
+ preempt_disable_notrace();
+
+ if (!printk_ratelimit())
+ goto out_enable;
+
+ printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x] "
+ "code: %s/%d\n",
+ preempt_count() - 1, current->comm, current->pid);
+ print_symbol("caller is %s\n", (long)__builtin_return_address(0));
+ dump_stack();
+
+out_enable:
+ preempt_enable_no_resched_notrace();
+out:
+ return this_cpu;
+}
+
+EXPORT_SYMBOL(debug_smp_processor_id);
+