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authorThomas Gleixner <tglx@tglx.tec.linutronix.de>2005-06-26 23:20:36 +0200
committerThomas Gleixner <tglx@mtd.linutronix.de>2005-06-26 23:20:36 +0200
commit7ca6448dbfb398bba36eda3c01bc14b86c3675be (patch)
tree82d934ebf07f22a2c64c3b6d82ec24082878b43a /lib/smp_processor_id.c
parentf1f67a9874f1a4bba1adff6d694aa52e5f52ff1a (diff)
parent7d681b23d6cc14a8c026ea6756242cb522cbbcae (diff)
downloadblackbird-op-linux-7ca6448dbfb398bba36eda3c01bc14b86c3675be.tar.gz
blackbird-op-linux-7ca6448dbfb398bba36eda3c01bc14b86c3675be.zip
Merge with rsync://fileserver/linux
Update to Linus latest
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 000000000000..42c08ef828c5
--- /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/module.h>
+#include <linux/kallsyms.h>
+
+unsigned int debug_smp_processor_id(void)
+{
+ unsigned long preempt_count = preempt_count();
+ int this_cpu = raw_smp_processor_id();
+ cpumask_t this_mask;
+
+ if (likely(preempt_count))
+ goto out;
+
+ if (irqs_disabled())
+ goto out;
+
+ /*
+ * Kernel threads bound to a single CPU can safely use
+ * smp_processor_id():
+ */
+ this_mask = cpumask_of_cpu(this_cpu);
+
+ if (cpus_equal(current->cpus_allowed, this_mask))
+ goto out;
+
+ /*
+ * It is valid to assume CPU-locality during early bootup:
+ */
+ if (system_state != SYSTEM_RUNNING)
+ goto out;
+
+ /*
+ * Avoid recursion:
+ */
+ preempt_disable();
+
+ if (!printk_ratelimit())
+ goto out_enable;
+
+ printk(KERN_ERR "BUG: using smp_processor_id() in preemptible [%08x] code: %s/%d\n", preempt_count(), current->comm, current->pid);
+ print_symbol("caller is %s\n", (long)__builtin_return_address(0));
+ dump_stack();
+
+out_enable:
+ preempt_enable_no_resched();
+out:
+ return this_cpu;
+}
+
+EXPORT_SYMBOL(debug_smp_processor_id);
+
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