1// SPDX-License-Identifier: GPL-2.0
2#ifndef __TRACE_STAT_H
3#define __TRACE_STAT_H
4
5#include <linux/seq_file.h>
6
7/*
8 * If you want to provide a stat file (one-shot statistics), fill
9 * an iterator with stat_start/stat_next and a stat_show callbacks.
10 * The others callbacks are optional.
11 */
12struct tracer_stat {
13 /* The name of your stat file */
14 const char *name;
15 /* Iteration over statistic entries */
16 void *(*stat_start)(struct tracer_stat *trace);
17 void *(*stat_next)(void *prev, int idx);
18 /* Compare two entries for stats sorting */
19 cmp_func_t stat_cmp;
20 /* Print a stat entry */
21 int (*stat_show)(struct seq_file *s, void *p);
22 /* Release an entry */
23 void (*stat_release)(void *stat);
24 /* Print the headers of your stat entries */
25 int (*stat_headers)(struct seq_file *s);
26};
27
28/*
29 * Destroy or create a stat file
30 */
31extern int register_stat_tracer(struct tracer_stat *trace);
32extern void unregister_stat_tracer(struct tracer_stat *trace);
33
34#endif /* __TRACE_STAT_H */
35

source code of linux/kernel/trace/trace_stat.h