Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/lin…

…ux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace
git-mirror · Mar 13, 2009 · 2084e02 · 2084e02
2 parents 4c6ed8f + 5cc9854
commit 2084e02
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Showing 16 changed files with 747 additions and 132 deletions.
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
@@ -258,6 +258,11 @@ enum
 	NR_SOFTIRQS
 };
 
+/* map softirq index to softirq name. update 'softirq_to_name' in
+ * kernel/softirq.c when adding a new softirq.
+ */
+extern char *softirq_to_name[NR_SOFTIRQS];
+
 /* softirq mask and active fields moved to irq_cpustat_t in
  * asm/hardirq.h to get better cache usage.  KAO
  */

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
@@ -452,31 +452,45 @@ do {									\
 
 #define trace_printk(fmt, args...)					\
 do {									\
-	static const char *trace_printk_fmt				\
-	__attribute__((section("__trace_printk_fmt")));			\
-									\
-	if (!trace_printk_fmt)						\
-		trace_printk_fmt = fmt;					\
-									\
 	__trace_printk_check_format(fmt, ##args);			\
-	__trace_printk(_THIS_IP_, trace_printk_fmt, ##args);		\
+	if (__builtin_constant_p(fmt)) {				\
+		static const char *trace_printk_fmt			\
+		  __attribute__((section("__trace_printk_fmt"))) =	\
+			__builtin_constant_p(fmt) ? fmt : NULL;		\
+									\
+		__trace_bprintk(_THIS_IP_, trace_printk_fmt, ##args);	\
+	} else								\
+		__trace_printk(_THIS_IP_, fmt, ##args);		\
 } while (0)
 
+extern int
+__trace_bprintk(unsigned long ip, const char *fmt, ...)
+	__attribute__ ((format (printf, 2, 3)));
+
 extern int
 __trace_printk(unsigned long ip, const char *fmt, ...)
 	__attribute__ ((format (printf, 2, 3)));
 
+/*
+ * The double __builtin_constant_p is because gcc will give us an error
+ * if we try to allocate the static variable to fmt if it is not a
+ * constant. Even with the outer if statement.
+ */
 #define ftrace_vprintk(fmt, vargs)					\
 do {									\
-	static const char *trace_printk_fmt				\
-	__attribute__((section("__trace_printk_fmt")));			\
-									\
-	if (!trace_printk_fmt)						\
-		trace_printk_fmt = fmt;					\
+	if (__builtin_constant_p(fmt)) {				\
+		static const char *trace_printk_fmt			\
+		  __attribute__((section("__trace_printk_fmt"))) =	\
+			__builtin_constant_p(fmt) ? fmt : NULL;		\
 									\
-	__ftrace_vprintk(_THIS_IP_, trace_printk_fmt, vargs);		\
+		__ftrace_vbprintk(_THIS_IP_, trace_printk_fmt, vargs);	\
+	} else								\
+		__ftrace_vprintk(_THIS_IP_, fmt, vargs);		\
 } while (0)
 
+extern int
+__ftrace_vbprintk(unsigned long ip, const char *fmt, va_list ap);
+
 extern int
 __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap);
 

diff --git a/include/trace/irq_event_types.h b/include/trace/irq_event_types.h
@@ -40,4 +40,16 @@ TRACE_EVENT(irq_handler_exit,
 		  __entry->irq, __entry->ret ? "handled" : "unhandled")
 );
 
+TRACE_FORMAT(softirq_entry,
+	TP_PROTO(struct softirq_action *h, struct softirq_action *vec),
+	TP_ARGS(h, vec),
+	TP_FMT("softirq=%d action=%s", (int)(h - vec), softirq_to_name[h-vec])
+	);
+
+TRACE_FORMAT(softirq_exit,
+	TP_PROTO(struct softirq_action *h, struct softirq_action *vec),
+	TP_ARGS(h, vec),
+	TP_FMT("softirq=%d action=%s", (int)(h - vec), softirq_to_name[h-vec])
+	);
+
 #undef TRACE_SYSTEM
diff --git a/kernel/softirq.c b/kernel/softirq.c
@@ -24,6 +24,7 @@
 #include <linux/ftrace.h>
 #include <linux/smp.h>
 #include <linux/tick.h>
+#include <trace/irq.h>
 
 #include <asm/irq.h>
 /*
@@ -53,6 +54,12 @@ static struct softirq_action softirq_vec[NR_SOFTIRQS] __cacheline_aligned_in_smp
 
 static DEFINE_PER_CPU(struct task_struct *, ksoftirqd);
 
+char *softirq_to_name[NR_SOFTIRQS] = {
+	"HI_SOFTIRQ", "TIMER_SOFTIRQ", "NET_TX_SOFTIRQ", "NET_RX_SOFTIRQ",
+	"BLOCK_SOFTIRQ", "TASKLET_SOFTIRQ", "SCHED_SOFTIRQ", "HRTIMER_SOFTIRQ",
+	"RCU_SOFTIRQ"
+};
+
 /*
  * we cannot loop indefinitely here to avoid userspace starvation,
  * but we also don't want to introduce a worst case 1/HZ latency
@@ -180,6 +187,9 @@ EXPORT_SYMBOL(local_bh_enable_ip);
  */
 #define MAX_SOFTIRQ_RESTART 10
 
+DEFINE_TRACE(softirq_entry);
+DEFINE_TRACE(softirq_exit);
+
 asmlinkage void __do_softirq(void)
 {
 	struct softirq_action *h;
@@ -206,12 +216,14 @@ asmlinkage void __do_softirq(void)
 		if (pending & 1) {
 			int prev_count = preempt_count();
 
+			trace_softirq_entry(h, softirq_vec);
 			h->action(h);
-
+			trace_softirq_exit(h, softirq_vec);
 			if (unlikely(prev_count != preempt_count())) {
-				printk(KERN_ERR "huh, entered softirq %td %p"
+				printk(KERN_ERR "huh, entered softirq %td %s %p"
 				       "with preempt_count %08x,"
 				       " exited with %08x?\n", h - softirq_vec,
+				       softirq_to_name[h - softirq_vec],
 				       h->action, prev_count, preempt_count());
 				preempt_count() = prev_count;
 			}