Commit dbd3fbdf authored by Li Zefan's avatar Li Zefan Committed by Frederic Weisbecker
Browse files

tracing/stat: do some cleanups



- remove duplicate code in stat_seq_init()
- update comments to reflect the change from stat list to stat rbtree

[ Impact: clean up ]
Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
parent e1622806
......@@ -93,10 +93,15 @@ static void destroy_session(struct stat_session *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
......@@ -118,12 +123,13 @@ insert_stat(struct rb_root *root, struct stat_node *data, cmp_stat_t cmp)
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)
{
......@@ -131,15 +137,14 @@ 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;
......@@ -154,23 +159,12 @@ static int stat_seq_init(struct stat_session *session)
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);
......@@ -179,22 +173,16 @@ static int stat_seq_init(struct stat_session *session)
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:
exit_free_rbtree:
reset_stat_session(session);
mutex_unlock(&session->stat_mutex);
return ret;
......@@ -207,7 +195,7 @@ static void *stat_seq_start(struct seq_file *s, loff_t *pos)
struct rb_node *node;
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 */
......@@ -280,7 +268,7 @@ static int tracing_stat_open(struct inode *inode, struct file *file)
}
/*
* 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)
{
......
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