---

yaml --- r: 140663 b: refs/heads/master c: 5ce1b1e h: refs/heads/master i: 140661: 268e7c9 140659: 32ff4ba 140655: 8386884 v: v3
git-mirror · Jan 26, 2009 · b4e7254 · b4e7254
1 parent e8e49b0
commit b4e7254
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Showing 6 changed files with 27 additions and 45 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 9005f3ebebfcfe9ccd731d16c468907a35ac1f9a
+refs/heads/master: 5ce1b1ed27d4ab1d81b8543a96f488bba2071576
diff --git a/trunk/include/linux/sched.h b/trunk/include/linux/sched.h
@@ -137,6 +137,8 @@ extern unsigned long nr_uninterruptible(void);
 extern unsigned long nr_active(void);
 extern unsigned long nr_iowait(void);
 
+extern unsigned long get_parent_ip(unsigned long addr);
+
 struct seq_file;
 struct cfs_rq;
 struct task_group;

diff --git a/trunk/kernel/sched.c b/trunk/kernel/sched.c
@@ -4399,10 +4399,7 @@ void scheduler_tick(void)
 #endif
 }
 
-#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
-				defined(CONFIG_PREEMPT_TRACER))
-
-static inline unsigned long get_parent_ip(unsigned long addr)
+unsigned long get_parent_ip(unsigned long addr)
 {
 	if (in_lock_functions(addr)) {
 		addr = CALLER_ADDR2;
@@ -4412,6 +4409,9 @@ static inline unsigned long get_parent_ip(unsigned long addr)
 	return addr;
 }
 
+#if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \
+				defined(CONFIG_PREEMPT_TRACER))
+
 void __kprobes add_preempt_count(int val)
 {
 #ifdef CONFIG_DEBUG_PREEMPT

diff --git a/trunk/kernel/softirq.c b/trunk/kernel/softirq.c
@@ -21,6 +21,7 @@
 #include <linux/freezer.h>
 #include <linux/kthread.h>
 #include <linux/rcupdate.h>
+#include <linux/ftrace.h>
 #include <linux/smp.h>
 #include <linux/tick.h>
 
@@ -79,13 +80,23 @@ static void __local_bh_disable(unsigned long ip)
 	WARN_ON_ONCE(in_irq());
 
 	raw_local_irq_save(flags);
-	add_preempt_count(SOFTIRQ_OFFSET);
+	/*
+	 * The preempt tracer hooks into add_preempt_count and will break
+	 * lockdep because it calls back into lockdep after SOFTIRQ_OFFSET
+	 * is set and before current->softirq_enabled is cleared.
+	 * We must manually increment preempt_count here and manually
+	 * call the trace_preempt_off later.
+	 */
+	preempt_count() += SOFTIRQ_OFFSET;
 	/*
 	 * Were softirqs turned off above:
 	 */
 	if (softirq_count() == SOFTIRQ_OFFSET)
 		trace_softirqs_off(ip);
 	raw_local_irq_restore(flags);
+
+	if (preempt_count() == SOFTIRQ_OFFSET)
+		trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
 }
 #else /* !CONFIG_TRACE_IRQFLAGS */
 static inline void __local_bh_disable(unsigned long ip)

diff --git a/trunk/kernel/trace/trace.c b/trunk/kernel/trace/trace.c
@@ -610,13 +610,12 @@ void tracing_start(void)
 		return;
 
 	spin_lock_irqsave(&tracing_start_lock, flags);
-	if (--trace_stop_count)
-		goto out;
-
-	if (trace_stop_count < 0) {
-		/* Someone screwed up their debugging */
-		WARN_ON_ONCE(1);
-		trace_stop_count = 0;
+	if (--trace_stop_count) {
+		if (trace_stop_count < 0) {
+			/* Someone screwed up their debugging */
+			WARN_ON_ONCE(1);
+			trace_stop_count = 0;
+		}
 		goto out;
 	}
 

diff --git a/trunk/kernel/trace/trace_irqsoff.c b/trunk/kernel/trace/trace_irqsoff.c
@@ -353,28 +353,18 @@ void trace_preempt_off(unsigned long a0, unsigned long a1)
 }
 #endif /* CONFIG_PREEMPT_TRACER */
 
-/*
- * save_tracer_enabled is used to save the state of the tracer_enabled
- * variable when we disable it when we open a trace output file.
- */
-static int save_tracer_enabled;
-
 static void start_irqsoff_tracer(struct trace_array *tr)
 {
 	register_ftrace_function(&trace_ops);
-	if (tracing_is_enabled()) {
+	if (tracing_is_enabled())
 		tracer_enabled = 1;
-		save_tracer_enabled = 1;
-	} else {
+	else
 		tracer_enabled = 0;
-		save_tracer_enabled = 0;
-	}
 }
 
 static void stop_irqsoff_tracer(struct trace_array *tr)
 {
 	tracer_enabled = 0;
-	save_tracer_enabled = 0;
 	unregister_ftrace_function(&trace_ops);
 }
 
@@ -395,25 +385,11 @@ static void irqsoff_tracer_reset(struct trace_array *tr)
 static void irqsoff_tracer_start(struct trace_array *tr)
 {
 	tracer_enabled = 1;
-	save_tracer_enabled = 1;
 }
 
 static void irqsoff_tracer_stop(struct trace_array *tr)
 {
 	tracer_enabled = 0;
-	save_tracer_enabled = 0;
-}
-
-static void irqsoff_tracer_open(struct trace_iterator *iter)
-{
-	/* stop the trace while dumping */
-	tracer_enabled = 0;
-}
-
-static void irqsoff_tracer_close(struct trace_iterator *iter)
-{
-	/* restart tracing */
-	tracer_enabled = save_tracer_enabled;
 }
 
 #ifdef CONFIG_IRQSOFF_TRACER
@@ -431,8 +407,6 @@ static struct tracer irqsoff_tracer __read_mostly =
 	.reset		= irqsoff_tracer_reset,
 	.start		= irqsoff_tracer_start,
 	.stop		= irqsoff_tracer_stop,
-	.open		= irqsoff_tracer_open,
-	.close		= irqsoff_tracer_close,
 	.print_max	= 1,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_irqsoff,
@@ -459,8 +433,6 @@ static struct tracer preemptoff_tracer __read_mostly =
 	.reset		= irqsoff_tracer_reset,
 	.start		= irqsoff_tracer_start,
 	.stop		= irqsoff_tracer_stop,
-	.open		= irqsoff_tracer_open,
-	.close		= irqsoff_tracer_close,
 	.print_max	= 1,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_preemptoff,
@@ -489,8 +461,6 @@ static struct tracer preemptirqsoff_tracer __read_mostly =
 	.reset		= irqsoff_tracer_reset,
 	.start		= irqsoff_tracer_start,
 	.stop		= irqsoff_tracer_stop,
-	.open		= irqsoff_tracer_open,
-	.close		= irqsoff_tracer_close,
 	.print_max	= 1,
 #ifdef CONFIG_FTRACE_SELFTEST
 	.selftest    = trace_selftest_startup_preemptirqsoff,