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trace_stat: Fix missing entry in stat file

PATCH In review Li Zefan 1 participant 6 messages Aug 17, 2009

Subsystems (2)
Tracing ftrace
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Li Zefan

author
#0 lore raw

PATCH 1/3 trace_stat: Fix missing entry in stat file

One entry is missing in the output of a stat file.

The cause is, when stat_seq_start() is called the 2nd time, we should start from the (pos-1)th elem in the rbtree but not pos, because pos == 0 is the header.

Signed-off-by Li Zefan <[email protected]>
---
 kernel/trace/trace_stat.c |   10 +++++++---
 1 files changed, 7 insertions(+), 3 deletions(-)
kernel/trace/trace_stat.c +7 -3
index 07c60b0..a4bb239 100644
@@ -203,17 +203,21 @@ static void *stat_seq_start(struct seq_file *s, loff_t *pos)
 {
 	struct stat_session *session = s->private;
 	struct rb_node *node;
+	int n = *pos;
 	int i;
 
 	/* Prevent from tracer switch or rbtree modification */
 	mutex_lock(&session->stat_mutex);
 
 	/* If we are in the beginning of the file, print the headers */
-	if (!*pos && session->ts->stat_headers)
-		return SEQ_START_TOKEN;
+	if (session->ts->stat_headers) {
+		if (n == 0)
+			return SEQ_START_TOKEN;
+		n--;
+	}
 
 	node = rb_first(&session->stat_root);
-	for (i = 0; node && i < *pos; i++)
+	for (i = 0; node && i < n; i++)
 		node = rb_next(node);
 
 	return node;
Signature · 1 line
1.6.3
author
#1 lore raw

PATCH 2/3 trace_stack: Simplify seqfile code

Extract duplicate code in t_start() and t_next().

Signed-off-by Li Zefan <[email protected]>
---
 kernel/trace/trace_stack.c |   34 ++++++++++++----------------------
 1 files changed, 12 insertions(+), 22 deletions(-)
kernel/trace/trace_stack.c +12 -22
index 0da1cff..0f6facb 100644
@@ -186,43 +186,33 @@ static const struct file_operations stack_max_size_fops = {
 };
 
 static void *
-t_next(struct seq_file *m, void *v, loff_t *pos)
+__next(struct seq_file *m, loff_t *pos)
 {
-	long i;
+	long n = *pos - 1;
 
-	(*pos)++;
-
-	if (v == SEQ_START_TOKEN)
-		i = 0;
-	else {
-		i = *(long *)v;
-		i++;
-	}
-
-	if (i >= max_stack_trace.nr_entries ||
-	    stack_dump_trace[i] == ULONG_MAX)
+	if (n >= max_stack_trace.nr_entries || stack_dump_trace[n] == ULONG_MAX)
 		return NULL;
 
-	m->private = (void *)i;
-
+	m->private = (void *)n;
 	return &m->private;
 }
 
-static void *t_start(struct seq_file *m, loff_t *pos)
+static void *
+t_next(struct seq_file *m, void *v, loff_t *pos)
 {
-	void *t = SEQ_START_TOKEN;
-	loff_t l = 0;
+	(*pos)++;
+	return __next(m, pos);
+}
 
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
 	local_irq_disable();
 	__raw_spin_lock(&max_stack_lock);
 
 	if (*pos == 0)
 		return SEQ_START_TOKEN;
 
-	for (; t && l < *pos; t = t_next(m, t, &l))
-		;
-
-	return t;
+	return __next(m, pos);
 }
 
 static void t_stop(struct seq_file *m, void *p)
Signature · 1 line
1.6.3
author
#2 lore raw

[tip:tracing/core] trace_stack: Simplify seqfile code

Commit-ID:  2fc5f0cff4cf1c4cd336d0f61f11bca6eeee1d84
Gitweb:     http://git.kernel.org/tip/2fc5f0cff4cf1c4cd336d0f61f11bca6eeee1d84
Author:     Li Zefan <[email protected]>
AuthorDate: Mon, 17 Aug 2009 16:53:37 +0800
Committer:  Ingo Molnar <[email protected]>
CommitDate: Mon, 17 Aug 2009 11:25:09 +0200

trace_stack: Simplify seqfile code

Extract duplicate code in t_start() and t_next().

Signed-off-by Li Zefan <[email protected]>
Cc Steven Rostedt <[email protected]>
Cc Frederic Weisbecker <[email protected]>

LKML-Reference: <[email protected]>

Signed-off-by Ingo Molnar <[email protected]>
---
 kernel/trace/trace_stack.c |   34 ++++++++++++----------------------
 1 files changed, 12 insertions(+), 22 deletions(-)
kernel/trace/trace_stack.c +12 -22
index 0da1cff..0f6facb 100644
@@ -186,43 +186,33 @@ static const struct file_operations stack_max_size_fops = {
 };
 
 static void *
-t_next(struct seq_file *m, void *v, loff_t *pos)
+__next(struct seq_file *m, loff_t *pos)
 {
-	long i;
+	long n = *pos - 1;
 
-	(*pos)++;
-
-	if (v == SEQ_START_TOKEN)
-		i = 0;
-	else {
-		i = *(long *)v;
-		i++;
-	}
-
-	if (i >= max_stack_trace.nr_entries ||
-	    stack_dump_trace[i] == ULONG_MAX)
+	if (n >= max_stack_trace.nr_entries || stack_dump_trace[n] == ULONG_MAX)
 		return NULL;
 
-	m->private = (void *)i;
-
+	m->private = (void *)n;
 	return &m->private;
 }
 
-static void *t_start(struct seq_file *m, loff_t *pos)
+static void *
+t_next(struct seq_file *m, void *v, loff_t *pos)
 {
-	void *t = SEQ_START_TOKEN;
-	loff_t l = 0;
+	(*pos)++;
+	return __next(m, pos);
+}
 
+static void *t_start(struct seq_file *m, loff_t *pos)
+{
 	local_irq_disable();
 	__raw_spin_lock(&max_stack_lock);
 
 	if (*pos == 0)
 		return SEQ_START_TOKEN;
 
-	for (; t && l < *pos; t = t_next(m, t, &l))
-		;
-
-	return t;
+	return __next(m, pos);
 }
 
 static void t_stop(struct seq_file *m, void *p)
author
#3 lore raw

PATCH 3/3 ftrace: Simplify seqfile code

In reply to Li Zefan

Use seq_release_private().

Signed-off-by Li Zefan <[email protected]>
---
 kernel/trace/ftrace.c |   15 ++-------------
 1 files changed, 2 insertions(+), 13 deletions(-)
kernel/trace/ftrace.c +2 -13
index 0948634..1993b71 100644
@@ -1556,17 +1556,6 @@ ftrace_avail_open(struct inode *inode, struct file *file)
 	return ret;
 }
 
-int ftrace_avail_release(struct inode *inode, struct file *file)
-{
-	struct seq_file *m = (struct seq_file *)file->private_data;
-	struct ftrace_iterator *iter = m->private;
-
-	seq_release(inode, file);
-	kfree(iter);
-
-	return 0;
-}
-
 static int
 ftrace_failures_open(struct inode *inode, struct file *file)
 {

@@ -2427,14 +2416,14 @@ static const struct file_operations ftrace_avail_fops = {
 	.open = ftrace_avail_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
-	.release = ftrace_avail_release,
+	.release = seq_release_private,
 };
 
 static const struct file_operations ftrace_failures_fops = {
 	.open = ftrace_failures_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
-	.release = ftrace_avail_release,
+	.release = seq_release_private,
 };
 
 static const struct file_operations ftrace_filter_fops = {
Signature · 1 line
1.6.3
author
#4 lore raw

[tip:tracing/core] ftrace: Simplify seqfile code

Commit-ID:  3be04b471b95b870bd129a138463756629e86f3f
Gitweb:     http://git.kernel.org/tip/3be04b471b95b870bd129a138463756629e86f3f
Author:     Li Zefan <[email protected]>
AuthorDate: Mon, 17 Aug 2009 16:54:03 +0800
Committer:  Ingo Molnar <[email protected]>
CommitDate: Mon, 17 Aug 2009 11:25:10 +0200

ftrace: Simplify seqfile code

Use seq_release_private().

Signed-off-by Li Zefan <[email protected]>
Cc Steven Rostedt <[email protected]>
Cc Frederic Weisbecker <[email protected]>
Cc Li Zefan <[email protected]>

LKML-Reference: <[email protected]>

Signed-off-by Ingo Molnar <[email protected]>
---
 kernel/trace/ftrace.c |   15 ++-------------
 1 files changed, 2 insertions(+), 13 deletions(-)
kernel/trace/ftrace.c +2 -13
index 0948634..1993b71 100644
@@ -1556,17 +1556,6 @@ ftrace_avail_open(struct inode *inode, struct file *file)
 	return ret;
 }
 
-int ftrace_avail_release(struct inode *inode, struct file *file)
-{
-	struct seq_file *m = (struct seq_file *)file->private_data;
-	struct ftrace_iterator *iter = m->private;
-
-	seq_release(inode, file);
-	kfree(iter);
-
-	return 0;
-}
-
 static int
 ftrace_failures_open(struct inode *inode, struct file *file)
 {

@@ -2427,14 +2416,14 @@ static const struct file_operations ftrace_avail_fops = {
 	.open = ftrace_avail_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
-	.release = ftrace_avail_release,
+	.release = seq_release_private,
 };
 
 static const struct file_operations ftrace_failures_fops = {
 	.open = ftrace_failures_open,
 	.read = seq_read,
 	.llseek = seq_lseek,
-	.release = ftrace_avail_release,
+	.release = seq_release_private,
 };
 
 static const struct file_operations ftrace_filter_fops = {
author
#5 lore raw
In reply to Li Zefan
Commit-ID:  97d53202a5670a08b79c8ef2e4fff1c1ee21317c
Gitweb:     http://git.kernel.org/tip/97d53202a5670a08b79c8ef2e4fff1c1ee21317c
Author:     Li Zefan <[email protected]>
AuthorDate: Mon, 17 Aug 2009 16:52:53 +0800
Committer:  Ingo Molnar <[email protected]>
CommitDate: Mon, 17 Aug 2009 11:25:09 +0200

trace_stat: Fix missing entry in stat file

One entry is missing in the output of a stat file.

The cause is, when stat_seq_start() is called the 2nd time, we should start from the (pos-1)th elem in the rbtree but not pos, because pos == 0 is the header.

Signed-off-by Li Zefan <[email protected]>
Cc Steven Rostedt <[email protected]>
Cc Frederic Weisbecker <[email protected]>

LKML-Reference: <[email protected]>

Signed-off-by Ingo Molnar <[email protected]>
---
 kernel/trace/trace_stat.c |   10 +++++++---
 1 files changed, 7 insertions(+), 3 deletions(-)
kernel/trace/trace_stat.c +7 -3
index 07c60b0..a4bb239 100644
@@ -203,17 +203,21 @@ static void *stat_seq_start(struct seq_file *s, loff_t *pos)
 {
 	struct stat_session *session = s->private;
 	struct rb_node *node;
+	int n = *pos;
 	int i;
 
 	/* Prevent from tracer switch or rbtree modification */
 	mutex_lock(&session->stat_mutex);
 
 	/* If we are in the beginning of the file, print the headers */
-	if (!*pos && session->ts->stat_headers)
-		return SEQ_START_TOKEN;
+	if (session->ts->stat_headers) {
+		if (n == 0)
+			return SEQ_START_TOKEN;
+		n--;
+	}
 
 	node = rb_first(&session->stat_root);
-	for (i = 0; node && i < *pos; i++)
+	for (i = 0; node && i < n; i++)
 		node = rb_next(node);
 
 	return node;