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-rw-r--r--kernel/trace/trace_stat.c140
1 files changed, 100 insertions, 40 deletions
diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c
index 3b6816be825..0bd0fc82da5 100644
--- a/kernel/trace/trace_stat.c
+++ b/kernel/trace/trace_stat.c
@@ -1,7 +1,7 @@
/*
* Infrastructure for statistic tracing (histogram output).
*
- * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
+ * Copyright (C) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com>
*
* Based on the code from trace_branch.c which is
* Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
@@ -10,14 +10,19 @@
#include <linux/list.h>
+#include <linux/rbtree.h>
#include <linux/debugfs.h>
#include "trace_stat.h"
#include "trace.h"
-/* List of stat entries from a tracer */
-struct trace_stat_list {
- struct list_head list;
+/*
+ * List of stat red-black nodes from a tracer
+ * We use a such tree to sort quickly the stat
+ * entries from the tracer.
+ */
+struct stat_node {
+ struct rb_node node;
void *stat;
};
@@ -25,7 +30,7 @@ struct trace_stat_list {
struct stat_session {
struct list_head session_list;
struct tracer_stat *ts;
- struct list_head stat_list;
+ struct rb_root stat_root;
struct mutex stat_mutex;
struct dentry *file;
};
@@ -37,15 +42,45 @@ static DEFINE_MUTEX(all_stat_sessions_mutex);
/* The root directory for all stat files */
static struct dentry *stat_dir;
+/*
+ * Iterate through the rbtree using a post order traversal path
+ * to release the next node.
+ * It won't necessary release one at each iteration
+ * but it will at least advance closer to the next one
+ * to be released.
+ */
+static struct rb_node *release_next(struct rb_node *node)
+{
+ struct stat_node *snode;
+ struct rb_node *parent = rb_parent(node);
+
+ if (node->rb_left)
+ return node->rb_left;
+ else if (node->rb_right)
+ return node->rb_right;
+ else {
+ if (!parent)
+ return NULL;
+ if (parent->rb_left == node)
+ parent->rb_left = NULL;
+ else
+ parent->rb_right = NULL;
+
+ snode = container_of(node, struct stat_node, node);
+ kfree(snode);
+
+ return parent;
+ }
+}
static void reset_stat_session(struct stat_session *session)
{
- struct trace_stat_list *node, *next;
+ struct rb_node *node = session->stat_root.rb_node;
- list_for_each_entry_safe(node, next, &session->stat_list, list)
- kfree(node);
+ while (node)
+ node = release_next(node);
- INIT_LIST_HEAD(&session->stat_list);
+ session->stat_root = RB_ROOT;
}
static void destroy_session(struct stat_session *session)
@@ -56,6 +91,35 @@ static void destroy_session(struct stat_session *session)
kfree(session);
}
+typedef int (*cmp_stat_t)(void *, void *);
+
+static void
+insert_stat(struct rb_root *root, struct stat_node *data, cmp_stat_t cmp)
+{
+ struct rb_node **new = &(root->rb_node), *parent = NULL;
+
+ /*
+ * Figure out where to put new node
+ * This is a descendent sorting
+ */
+ while (*new) {
+ struct stat_node *this;
+ int result;
+
+ this = container_of(*new, struct stat_node, node);
+ result = cmp(data->stat, this->stat);
+
+ parent = *new;
+ if (result >= 0)
+ new = &((*new)->rb_left);
+ else
+ new = &((*new)->rb_right);
+ }
+
+ rb_link_node(&data->node, parent, new);
+ rb_insert_color(&data->node, root);
+}
+
/*
* For tracers that don't provide a stat_cmp callback.
* This one will force an immediate insertion on tail of
@@ -73,8 +137,9 @@ static int dummy_cmp(void *p1, void *p2)
*/
static int stat_seq_init(struct stat_session *session)
{
- struct trace_stat_list *iter_entry, *new_entry;
struct tracer_stat *ts = session->ts;
+ struct stat_node *new_entry;
+ struct rb_root *root;
void *stat;
int ret = 0;
int i;
@@ -93,15 +158,13 @@ static int stat_seq_init(struct stat_session *session)
* The first entry. Actually this is the second, but the first
* one (the stat_list head) is pointless.
*/
- new_entry = kmalloc(sizeof(struct trace_stat_list), GFP_KERNEL);
+ new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL);
if (!new_entry) {
ret = -ENOMEM;
goto exit;
}
-
- INIT_LIST_HEAD(&new_entry->list);
-
- list_add(&new_entry->list, &session->stat_list);
+ root = &session->stat_root;
+ insert_stat(root, new_entry, dummy_cmp);
new_entry->stat = stat;
@@ -116,31 +179,17 @@ static int stat_seq_init(struct stat_session *session)
if (!stat)
break;
- new_entry = kmalloc(sizeof(struct trace_stat_list), GFP_KERNEL);
+ new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL);
if (!new_entry) {
ret = -ENOMEM;
goto exit_free_list;
}
- INIT_LIST_HEAD(&new_entry->list);
new_entry->stat = stat;
- list_for_each_entry_reverse(iter_entry, &session->stat_list,
- list) {
-
- /* Insertion with a descendent sorting */
- if (ts->stat_cmp(iter_entry->stat,
- new_entry->stat) >= 0) {
-
- list_add(&new_entry->list, &iter_entry->list);
- break;
- }
- }
-
- /* The current larger value */
- if (list_empty(&new_entry->list))
- list_add(&new_entry->list, &session->stat_list);
+ insert_stat(root, new_entry, ts->stat_cmp);
}
+
exit:
mutex_unlock(&session->stat_mutex);
return ret;
@@ -155,25 +204,38 @@ exit_free_list:
static void *stat_seq_start(struct seq_file *s, loff_t *pos)
{
struct stat_session *session = s->private;
+ struct rb_node *node;
+ int i;
/* Prevent from tracer switch or stat_list modification */
mutex_lock(&session->stat_mutex);
/* If we are in the beginning of the file, print the headers */
- if (!*pos && session->ts->stat_headers)
+ if (!*pos && session->ts->stat_headers) {
+ (*pos)++;
return SEQ_START_TOKEN;
+ }
- return seq_list_start(&session->stat_list, *pos);
+ node = rb_first(&session->stat_root);
+ for (i = 0; node && i < *pos; i++)
+ node = rb_next(node);
+
+ (*pos)++;
+
+ return node;
}
static void *stat_seq_next(struct seq_file *s, void *p, loff_t *pos)
{
struct stat_session *session = s->private;
+ struct rb_node *node = p;
+
+ (*pos)++;
if (p == SEQ_START_TOKEN)
- return seq_list_start(&session->stat_list, *pos);
+ return rb_first(&session->stat_root);
- return seq_list_next(p, &session->stat_list, pos);
+ return rb_next(node);
}
static void stat_seq_stop(struct seq_file *s, void *p)
@@ -185,7 +247,7 @@ static void stat_seq_stop(struct seq_file *s, void *p)
static int stat_seq_show(struct seq_file *s, void *v)
{
struct stat_session *session = s->private;
- struct trace_stat_list *l = list_entry(v, struct trace_stat_list, list);
+ struct stat_node *l = container_of(v, struct stat_node, node);
if (v == SEQ_START_TOKEN)
return session->ts->stat_headers(s);
@@ -286,15 +348,13 @@ int register_stat_tracer(struct tracer_stat *trace)
mutex_unlock(&all_stat_sessions_mutex);
/* Init the session */
- session = kmalloc(sizeof(struct stat_session), GFP_KERNEL);
+ session = kzalloc(sizeof(*session), GFP_KERNEL);
if (!session)
return -ENOMEM;
session->ts = trace;
INIT_LIST_HEAD(&session->session_list);
- INIT_LIST_HEAD(&session->stat_list);
mutex_init(&session->stat_mutex);
- session->file = NULL;
ret = init_stat_file(session);
if (ret) {
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-20 00:34:57 +0000