Merge branch 'tip/tracing/ftrace' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/ftrace

kernel/trace/blktrace.c

@@ -1231,7 +1231,6 @@ static struct tracer blk_tracer __read_mostly = {
 static struct trace_event trace_blk_event = {
 	.type	 	= TRACE_BLK,
 	.trace		= blk_trace_event_print,
-	.latency_trace	= blk_trace_event_print,
 	.binary		= blk_trace_event_print_binary,
 };
 

kernel/trace/ring_buffer.c

@@ -2461,6 +2461,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
 	unsigned long flags;
 	unsigned int commit;
 	unsigned int read;
+	u64 save_timestamp;
 	int ret = -1;
 
 	/*
@@ -2515,6 +2516,9 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
 		if (len < size)
 			goto out;
 
+		/* save the current timestamp, since the user will need it */
+		save_timestamp = cpu_buffer->read_stamp;
+
 		/* Need to copy one event at a time */
 		do {
 			memcpy(bpage->data + pos, rpage->data + rpos, size);
@@ -2531,7 +2535,7 @@ int ring_buffer_read_page(struct ring_buffer *buffer,
 
 		/* update bpage */
 		local_set(&bpage->commit, pos);
-		bpage->time_stamp = rpage->time_stamp;
+		bpage->time_stamp = save_timestamp;
 
 		/* we copied everything to the beginning */
 		read = 0;

kernel/trace/trace.c

@@ -299,6 +299,7 @@ static const char *trace_options[] = {
 	"sym-userobj",
 	"printk-msg-only",
 	"context-info",
+	"latency-format",
 	NULL
 };
 
@@ -346,6 +347,9 @@ ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
 	int len;
 	int ret;
 
+	if (!cnt)
+		return 0;
+
 	if (s->len <= s->readpos)
 		return -EBUSY;
 
@@ -353,10 +357,12 @@ ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
 	if (cnt > len)
 		cnt = len;
 	ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
-	if (ret)
+	if (ret == cnt)
 		return -EFAULT;
 
-	s->readpos += len;
+	cnt -= ret;
+
+	s->readpos += cnt;
 	return cnt;
 }
 
@@ -375,7 +381,7 @@ ssize_t trace_seq_to_buffer(struct trace_seq *s, void *buf, size_t cnt)
 	if (!ret)
 		return -EFAULT;
 
-	s->readpos += len;
+	s->readpos += cnt;
 	return cnt;
 }
 
@@ -1462,33 +1468,6 @@ static void test_cpu_buff_start(struct trace_iterator *iter)
 	trace_seq_printf(s, "##### CPU %u buffer started ####\n", iter->cpu);
 }
 
-static enum print_line_t print_lat_fmt(struct trace_iterator *iter)
-{
-	struct trace_seq *s = &iter->seq;
-	unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK);
-	struct trace_event *event;
-	struct trace_entry *entry = iter->ent;
-
-	test_cpu_buff_start(iter);
-
-	event = ftrace_find_event(entry->type);
-
-	if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
-		if (!trace_print_lat_context(iter))
-			goto partial;
-	}
-
-	if (event)
-		return event->latency_trace(iter, sym_flags);
-
-	if (!trace_seq_printf(s, "Unknown type %d\n", entry->type))
-		goto partial;
-
-	return TRACE_TYPE_HANDLED;
-partial:
-	return TRACE_TYPE_PARTIAL_LINE;
-}
-
 static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
 {
 	struct trace_seq *s = &iter->seq;
@@ -1503,8 +1482,13 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
 	event = ftrace_find_event(entry->type);
 
 	if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
-		if (!trace_print_context(iter))
-			goto partial;
+		if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
+			if (!trace_print_lat_context(iter))
+				goto partial;
+		} else {
+			if (!trace_print_context(iter))
+				goto partial;
+		}
 	}
 
 	if (event)
@@ -1646,9 +1630,6 @@ static enum print_line_t print_trace_line(struct trace_iterator *iter)
 	if (trace_flags & TRACE_ITER_RAW)
 		return print_raw_fmt(iter);
 
-	if (iter->iter_flags & TRACE_FILE_LAT_FMT)
-		return print_lat_fmt(iter);
-
 	return print_trace_fmt(iter);
 }
 
@@ -1824,26 +1805,12 @@ static int tracing_open(struct inode *inode, struct file *file)
 	iter = __tracing_open(inode, file);
 	if (IS_ERR(iter))
 		ret = PTR_ERR(iter);
-
-	return ret;
-}
-
-static int tracing_lt_open(struct inode *inode, struct file *file)
-{
-	struct trace_iterator *iter;
-	int ret = 0;
-
-	iter = __tracing_open(inode, file);
-
-	if (IS_ERR(iter))
-		ret = PTR_ERR(iter);
-	else
+	else if (trace_flags & TRACE_ITER_LATENCY_FMT)
 		iter->iter_flags |= TRACE_FILE_LAT_FMT;
 
 	return ret;
 }
 
-
 static void *
 t_next(struct seq_file *m, void *v, loff_t *pos)
 {
@@ -1922,13 +1889,6 @@ static struct file_operations tracing_fops = {
 	.release	= tracing_release,
 };
 
-static struct file_operations tracing_lt_fops = {
-	.open		= tracing_lt_open,
-	.read		= seq_read,
-	.llseek		= seq_lseek,
-	.release	= tracing_release,
-};
-
 static struct file_operations show_traces_fops = {
 	.open		= show_traces_open,
 	.read		= seq_read,
@@ -3049,6 +3009,9 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
 	ssize_t ret;
 	size_t size;
 
+	if (!count)
+		return 0;
+
 	/* Do we have previous read data to read? */
 	if (info->read < PAGE_SIZE)
 		goto read;
@@ -3073,8 +3036,10 @@ read:
 		size = count;
 
 	ret = copy_to_user(ubuf, info->spare + info->read, size);
-	if (ret)
+	if (ret == size)
 		return -EFAULT;
+	size -= ret;
+
 	*ppos += size;
 	info->read += size;
 
@@ -3918,8 +3883,10 @@ void ftrace_dump(void)
 
 	printk(KERN_TRACE "Dumping ftrace buffer:\n");
 
+	/* Simulate the iterator */
 	iter.tr = &global_trace;
 	iter.trace = current_trace;
+	iter.cpu_file = TRACE_PIPE_ALL_CPU;
 
 	/*
 	 * We need to stop all tracing on all CPUS to read the

kernel/trace/trace.h

@@ -651,7 +651,8 @@ enum trace_iterator_flags {
 	TRACE_ITER_USERSTACKTRACE       = 0x4000,
 	TRACE_ITER_SYM_USEROBJ          = 0x8000,
 	TRACE_ITER_PRINTK_MSGONLY	= 0x10000,
-	TRACE_ITER_CONTEXT_INFO		= 0x20000 /* Print pid/cpu/time */
+	TRACE_ITER_CONTEXT_INFO		= 0x20000, /* Print pid/cpu/time */
+	TRACE_ITER_LATENCY_FMT		= 0x40000,
 };
 
 /*

kernel/trace/trace_branch.c

@@ -159,7 +159,6 @@ static enum print_line_t trace_branch_print(struct trace_iterator *iter,
 static struct trace_event trace_branch_event = {
 	.type	 	= TRACE_BRANCH,
 	.trace		= trace_branch_print,
-	.latency_trace	= trace_branch_print,
 };
 
 static struct tracer branch_trace __read_mostly =

kernel/trace/trace_irqsoff.c

@@ -32,6 +32,8 @@ enum {
 
 static int trace_type __read_mostly;
 
+static int save_lat_flag;
+
 #ifdef CONFIG_PREEMPT_TRACER
 static inline int
 preempt_trace(void)
@@ -370,6 +372,9 @@ static void stop_irqsoff_tracer(struct trace_array *tr)
 
 static void __irqsoff_tracer_init(struct trace_array *tr)
 {
+	save_lat_flag = trace_flags & TRACE_ITER_LATENCY_FMT;
+	trace_flags |= TRACE_ITER_LATENCY_FMT;
+
 	tracing_max_latency = 0;
 	irqsoff_trace = tr;
 	/* make sure that the tracer is visible */
@@ -380,6 +385,9 @@ static void __irqsoff_tracer_init(struct trace_array *tr)
 static void irqsoff_tracer_reset(struct trace_array *tr)
 {
 	stop_irqsoff_tracer(tr);
+
+	if (!save_lat_flag)
+		trace_flags &= ~TRACE_ITER_LATENCY_FMT;
 }
 
 static void irqsoff_tracer_start(struct trace_array *tr)

kernel/trace/trace_output.c

@@ -437,8 +437,6 @@ int register_ftrace_event(struct trace_event *event)
 
 	if (event->trace == NULL)
 		event->trace = trace_nop_print;
-	if (event->latency_trace == NULL)
-		event->latency_trace = trace_nop_print;
 	if (event->raw == NULL)
 		event->raw = trace_nop_print;
 	if (event->hex == NULL)
@@ -480,29 +478,6 @@ enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags)
 }
 
 /* TRACE_FN */
-static enum print_line_t trace_fn_latency(struct trace_iterator *iter,
-					  int flags)
-{
-	struct ftrace_entry *field;
-	struct trace_seq *s = &iter->seq;
-
-	trace_assign_type(field, iter->ent);
-
-	if (!seq_print_ip_sym(s, field->ip, flags))
-		goto partial;
-	if (!trace_seq_puts(s, " ("))
-		goto partial;
-	if (!seq_print_ip_sym(s, field->parent_ip, flags))
-		goto partial;
-	if (!trace_seq_puts(s, ")\n"))
-		goto partial;
-
-	return TRACE_TYPE_HANDLED;
-
- partial:
-	return TRACE_TYPE_PARTIAL_LINE;
-}
-
 static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags)
 {
 	struct ftrace_entry *field;
@@ -573,7 +548,6 @@ static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags)
 static struct trace_event trace_fn_event = {
 	.type	 	= TRACE_FN,
 	.trace		= trace_fn_trace,
-	.latency_trace	= trace_fn_latency,
 	.raw		= trace_fn_raw,
 	.hex		= trace_fn_hex,
 	.binary		= trace_fn_bin,
@@ -705,7 +679,6 @@ static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,
 static struct trace_event trace_ctx_event = {
 	.type	 	= TRACE_CTX,
 	.trace		= trace_ctx_print,
-	.latency_trace	= trace_ctx_print,
 	.raw		= trace_ctx_raw,
 	.hex		= trace_ctx_hex,
 	.binary		= trace_ctxwake_bin,
@@ -714,7 +687,6 @@ static struct trace_event trace_ctx_event = {
 static struct trace_event trace_wake_event = {
 	.type	 	= TRACE_WAKE,
 	.trace		= trace_wake_print,
-	.latency_trace	= trace_wake_print,
 	.raw		= trace_wake_raw,
 	.hex		= trace_wake_hex,
 	.binary		= trace_ctxwake_bin,
@@ -770,7 +742,6 @@ static enum print_line_t trace_special_bin(struct trace_iterator *iter,
 static struct trace_event trace_special_event = {
 	.type	 	= TRACE_SPECIAL,
 	.trace		= trace_special_print,
-	.latency_trace	= trace_special_print,
 	.raw		= trace_special_print,
 	.hex		= trace_special_hex,
 	.binary		= trace_special_bin,
@@ -808,7 +779,6 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter,
 static struct trace_event trace_stack_event = {
 	.type	 	= TRACE_STACK,
 	.trace		= trace_stack_print,
-	.latency_trace	= trace_stack_print,
 	.raw		= trace_special_print,
 	.hex		= trace_special_hex,
 	.binary		= trace_special_bin,
@@ -838,7 +808,6 @@ static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,
 static struct trace_event trace_user_stack_event = {
 	.type	 	= TRACE_USER_STACK,
 	.trace		= trace_user_stack_print,
-	.latency_trace	= trace_user_stack_print,
 	.raw		= trace_special_print,
 	.hex		= trace_special_hex,
 	.binary		= trace_special_bin,
@@ -883,7 +852,6 @@ static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags)
 static struct trace_event trace_print_event = {
 	.type	 	= TRACE_PRINT,
 	.trace		= trace_print_print,
-	.latency_trace	= trace_print_print,
 	.raw		= trace_print_raw,
 };
 

kernel/trace/trace_output.h

@@ -10,7 +10,6 @@ struct trace_event {
 	struct hlist_node	node;
 	int			type;
 	trace_print_func	trace;
-	trace_print_func	latency_trace;
 	trace_print_func	raw;
 	trace_print_func	hex;
 	trace_print_func	binary;

kernel/trace/trace_sched_wakeup.c

@@ -32,6 +32,8 @@ static raw_spinlock_t wakeup_lock =
 
 static void __wakeup_reset(struct trace_array *tr);
 
+static int save_lat_flag;
+
 #ifdef CONFIG_FUNCTION_TRACER
 /*
  * irqsoff uses its own tracer function to keep the overhead down:
@@ -324,6 +326,9 @@ static void stop_wakeup_tracer(struct trace_array *tr)
 
 static int __wakeup_tracer_init(struct trace_array *tr)
 {
+	save_lat_flag = trace_flags & TRACE_ITER_LATENCY_FMT;
+	trace_flags |= TRACE_ITER_LATENCY_FMT;
+
 	tracing_max_latency = 0;
 	wakeup_trace = tr;
 	start_wakeup_tracer(tr);
@@ -347,6 +352,9 @@ static void wakeup_tracer_reset(struct trace_array *tr)
 	stop_wakeup_tracer(tr);
 	/* make sure we put back any tasks we are tracing */
 	wakeup_reset(tr);
+
+	if (!save_lat_flag)
+		trace_flags &= ~TRACE_ITER_LATENCY_FMT;
 }
 
 static void wakeup_tracer_start(struct trace_array *tr)