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-rw-r--r--kernel/trace/trace_stat.c54
1 files changed, 21 insertions, 33 deletions
diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c
index 8030ec98dbad..17f20ebdad2a 100644
--- a/kernel/trace/trace_stat.c
+++ b/kernel/trace/trace_stat.c
@@ -93,10 +93,15 @@ static void destroy_session(struct stat_session *session)
93 93
94typedef int (*cmp_stat_t)(void *, void *); 94typedef int (*cmp_stat_t)(void *, void *);
95 95
96static void 96static int insert_stat(struct rb_root *root, void *stat, cmp_stat_t cmp)
97insert_stat(struct rb_root *root, struct stat_node *data, cmp_stat_t cmp)
98{ 97{
99 struct rb_node **new = &(root->rb_node), *parent = NULL; 98 struct rb_node **new = &(root->rb_node), *parent = NULL;
99 struct stat_node *data;
100
101 data = kzalloc(sizeof(*data), GFP_KERNEL);
102 if (!data)
103 return -ENOMEM;
104 data->stat = stat;
100 105
101 /* 106 /*
102 * Figure out where to put new node 107 * 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)
118 123
119 rb_link_node(&data->node, parent, new); 124 rb_link_node(&data->node, parent, new);
120 rb_insert_color(&data->node, root); 125 rb_insert_color(&data->node, root);
126 return 0;
121} 127}
122 128
123/* 129/*
124 * For tracers that don't provide a stat_cmp callback. 130 * For tracers that don't provide a stat_cmp callback.
125 * This one will force an immediate insertion on tail of 131 * This one will force an insertion as right-most node
126 * the list. 132 * in the rbtree.
127 */ 133 */
128static int dummy_cmp(void *p1, void *p2) 134static int dummy_cmp(void *p1, void *p2)
129{ 135{
@@ -131,15 +137,14 @@ static int dummy_cmp(void *p1, void *p2)
131} 137}
132 138
133/* 139/*
134 * Initialize the stat list at each trace_stat file opening. 140 * Initialize the stat rbtree at each trace_stat file opening.
135 * All of these copies and sorting are required on all opening 141 * All of these copies and sorting are required on all opening
136 * since the stats could have changed between two file sessions. 142 * since the stats could have changed between two file sessions.
137 */ 143 */
138static int stat_seq_init(struct stat_session *session) 144static int stat_seq_init(struct stat_session *session)
139{ 145{
140 struct tracer_stat *ts = session->ts; 146 struct tracer_stat *ts = session->ts;
141 struct stat_node *new_entry; 147 struct rb_root *root = &session->stat_root;
142 struct rb_root *root;
143 void *stat; 148 void *stat;
144 int ret = 0; 149 int ret = 0;
145 int i; 150 int i;
@@ -154,23 +159,12 @@ static int stat_seq_init(struct stat_session *session)
154 if (!stat) 159 if (!stat)
155 goto exit; 160 goto exit;
156 161
157 /* 162 ret = insert_stat(root, stat, ts->stat_cmp);
158 * The first entry. Actually this is the second, but the first 163 if (ret)
159 * one (the stat_list head) is pointless.
160 */
161 new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL);
162 if (!new_entry) {
163 ret = -ENOMEM;
164 goto exit; 164 goto exit;
165 }
166 root = &session->stat_root;
167 insert_stat(root, new_entry, dummy_cmp);
168
169 new_entry->stat = stat;
170 165
171 /* 166 /*
172 * Iterate over the tracer stat entries and store them in a sorted 167 * Iterate over the tracer stat entries and store them in an rbtree.
173 * list.
174 */ 168 */
175 for (i = 1; ; i++) { 169 for (i = 1; ; i++) {
176 stat = ts->stat_next(stat, i); 170 stat = ts->stat_next(stat, i);
@@ -179,22 +173,16 @@ static int stat_seq_init(struct stat_session *session)
179 if (!stat) 173 if (!stat)
180 break; 174 break;
181 175
182 new_entry = kzalloc(sizeof(*new_entry), GFP_KERNEL); 176 ret = insert_stat(root, stat, ts->stat_cmp);
183 if (!new_entry) { 177 if (ret)
184 ret = -ENOMEM; 178 goto exit_free_rbtree;
185 goto exit_free_list;
186 }
187
188 new_entry->stat = stat;
189
190 insert_stat(root, new_entry, ts->stat_cmp);
191 } 179 }
192 180
193exit: 181exit:
194 mutex_unlock(&session->stat_mutex); 182 mutex_unlock(&session->stat_mutex);
195 return ret; 183 return ret;
196 184
197exit_free_list: 185exit_free_rbtree:
198 reset_stat_session(session); 186 reset_stat_session(session);
199 mutex_unlock(&session->stat_mutex); 187 mutex_unlock(&session->stat_mutex);
200 return ret; 188 return ret;
@@ -207,7 +195,7 @@ static void *stat_seq_start(struct seq_file *s, loff_t *pos)
207 struct rb_node *node; 195 struct rb_node *node;
208 int i; 196 int i;
209 197
210 /* Prevent from tracer switch or stat_list modification */ 198 /* Prevent from tracer switch or rbtree modification */
211 mutex_lock(&session->stat_mutex); 199 mutex_lock(&session->stat_mutex);
212 200
213 /* If we are in the beginning of the file, print the headers */ 201 /* 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)
280} 268}
281 269
282/* 270/*
283 * Avoid consuming memory with our now useless list. 271 * Avoid consuming memory with our now useless rbtree.
284 */ 272 */
285static int tracing_stat_release(struct inode *i, struct file *f) 273static int tracing_stat_release(struct inode *i, struct file *f)
286{ 274{