#include <linux/list.h>
+#include <linux/slab.h>
#include <linux/rbtree.h>
#include <linux/debugfs.h>
#include "trace_stat.h"
* but it will at least advance closer to the next one
* to be released.
*/
-static struct rb_node *release_next(struct rb_node *node)
+static struct rb_node *release_next(struct tracer_stat *ts,
+ struct rb_node *node)
{
struct stat_node *snode;
struct rb_node *parent = rb_parent(node);
parent->rb_right = NULL;
snode = container_of(node, struct stat_node, node);
+ if (ts->stat_release)
+ ts->stat_release(snode->stat);
kfree(snode);
return parent;
}
}
-static void reset_stat_session(struct stat_session *session)
+static void __reset_stat_session(struct stat_session *session)
{
struct rb_node *node = session->stat_root.rb_node;
while (node)
- node = release_next(node);
+ node = release_next(session->ts, node);
session->stat_root = RB_ROOT;
}
+static void reset_stat_session(struct stat_session *session)
+{
+ mutex_lock(&session->stat_mutex);
+ __reset_stat_session(session);
+ mutex_unlock(&session->stat_mutex);
+}
+
static void destroy_session(struct stat_session *session)
{
debugfs_remove(session->file);
- reset_stat_session(session);
+ __reset_stat_session(session);
mutex_destroy(&session->stat_mutex);
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)
+static int insert_stat(struct rb_root *root, void *stat, cmp_stat_t cmp)
{
struct rb_node **new = &(root->rb_node), *parent = NULL;
+ struct stat_node *data;
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+ data->stat = stat;
/*
* Figure out where to put new node
rb_link_node(&data->node, parent, new);
rb_insert_color(&data->node, root);
+ return 0;
}
/*
* For tracers that don't provide a stat_cmp callback.
- * This one will force an immediate insertion on tail of
- * the list.
+ * This one will force an insertion as right-most node
+ * in the rbtree.
*/
static int dummy_cmp(void *p1, void *p2)
{
}
/*
- * Initialize the stat list at each trace_stat file opening.
+ * Initialize the stat rbtree at each trace_stat file opening.
* All of these copies and sorting are required on all opening
* since the stats could have changed between two file sessions.
*/
static int stat_seq_init(struct stat_session *session)
{
struct tracer_stat *ts = session->ts;
- struct stat_node *new_entry;
- struct rb_root *root;
+ struct rb_root *root = &session->stat_root;
void *stat;
int ret = 0;
int i;
mutex_lock(&session->stat_mutex);
- reset_stat_session(session);
+ __reset_stat_session(session);
if (!ts->stat_cmp)
ts->stat_cmp = dummy_cmp;
if (!stat)
goto exit;
- /*
- * The first entry. Actually this is the second, but the first
- * one (the stat_list head) is pointless.
- */
- new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL);
- if (!new_entry) {
- ret = -ENOMEM;
+ ret = insert_stat(root, stat, ts->stat_cmp);
+ if (ret)
goto exit;
- }
- root = &session->stat_root;
- insert_stat(root, new_entry, dummy_cmp);
-
- new_entry->stat = stat;
/*
- * Iterate over the tracer stat entries and store them in a sorted
- * list.
+ * Iterate over the tracer stat entries and store them in an rbtree.
*/
for (i = 1; ; i++) {
stat = ts->stat_next(stat, i);
if (!stat)
break;
- new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL);
- if (!new_entry) {
- ret = -ENOMEM;
- goto exit_free_list;
- }
-
- new_entry->stat = stat;
-
- insert_stat(root, new_entry, ts->stat_cmp);
+ ret = insert_stat(root, stat, ts->stat_cmp);
+ if (ret)
+ goto exit_free_rbtree;
}
exit:
mutex_unlock(&session->stat_mutex);
return ret;
-exit_free_list:
- reset_stat_session(session);
+exit_free_rbtree:
+ __reset_stat_session(session);
mutex_unlock(&session->stat_mutex);
return ret;
}
{
struct stat_session *session = s->private;
struct rb_node *node;
+ int n = *pos;
int i;
- /* Prevent from tracer switch or stat_list modification */
+ /* 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) {
- (*pos)++;
- 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);
- (*pos)++;
-
return node;
}
static int tracing_stat_open(struct inode *inode, struct file *file)
{
int ret;
-
+ struct seq_file *m;
struct stat_session *session = inode->i_private;
+ ret = stat_seq_init(session);
+ if (ret)
+ return ret;
+
ret = seq_open(file, &trace_stat_seq_ops);
- if (!ret) {
- struct seq_file *m = file->private_data;
- m->private = session;
- ret = stat_seq_init(session);
+ if (ret) {
+ reset_stat_session(session);
+ return ret;
}
+ m = file->private_data;
+ m->private = session;
return ret;
}
/*
- * Avoid consuming memory with our now useless list.
+ * Avoid consuming memory with our now useless rbtree.
*/
static int tracing_stat_release(struct inode *i, struct file *f)
{
struct stat_session *session = i->i_private;
- mutex_lock(&session->stat_mutex);
reset_stat_session(session);
- mutex_unlock(&session->stat_mutex);
- return 0;
+ return seq_release(i, f);
}
static const struct file_operations tracing_stat_fops = {
int register_stat_tracer(struct tracer_stat *trace)
{
- struct stat_session *session, *node, *tmp;
+ struct stat_session *session, *node;
int ret;
if (!trace)
/* Already registered? */
mutex_lock(&all_stat_sessions_mutex);
- list_for_each_entry_safe(node, tmp, &all_stat_sessions, session_list) {
+ list_for_each_entry(node, &all_stat_sessions, session_list) {
if (node->ts == trace) {
mutex_unlock(&all_stat_sessions_mutex);
return -EINVAL;
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff