[PATCH] lockdep: irqtrace subsystem, core

[linux-2.6.git] / include / linux / hardirq.h

diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 114ae583cca9a28480ba684c342a54b97bf46686..b1d4332b5cf0f22e2bf6f2fabf6aadb0b41f1680 100644 (file)
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -86,9 +86,6 @@ extern void synchronize_irq(unsigned int irq);
 # define synchronize_irq(irq)  barrier()
 #endif
 
-#define nmi_enter()            irq_enter()
-#define nmi_exit()             sub_preempt_count(HARDIRQ_OFFSET)
-
 struct task_struct;
 
 #ifndef CONFIG_VIRT_CPU_ACCOUNTING
@@ -97,12 +94,35 @@ static inline void account_system_vtime(struct task_struct *tsk)
 }
 #endif
 
+/*
+ * It is safe to do non-atomic ops on ->hardirq_context,
+ * because NMI handlers may not preempt and the ops are
+ * always balanced, so the interrupted value of ->hardirq_context
+ * will always be restored.
+ */
 #define irq_enter()                                    \
        do {                                            \
                account_system_vtime(current);          \
                add_preempt_count(HARDIRQ_OFFSET);      \
+               trace_hardirq_enter();                  \
+       } while (0)
+
+/*
+ * Exit irq context without processing softirqs:
+ */
+#define __irq_exit()                                   \
+       do {                                            \
+               trace_hardirq_exit();                   \
+               account_system_vtime(current);          \
+               sub_preempt_count(HARDIRQ_OFFSET);      \
        } while (0)
 
+/*
+ * Exit irq context and process softirqs if needed:
+ */
 extern void irq_exit(void);
 
+#define nmi_enter()            irq_enter()
+#define nmi_exit()             __irq_exit()
+
 #endif /* LINUX_HARDIRQ_H */