linux/kernel/locking/lock_events.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * Authors: Waiman Long <[email protected]>
 */

#ifndef __LOCKING_LOCK_EVENTS_H
#define __LOCKING_LOCK_EVENTS_H

enum lock_events { … };

#ifdef CONFIG_LOCK_EVENT_COUNTS
/*
 * Per-cpu counters
 */
DECLARE_PER_CPU(unsigned long, lockevents[lockevent_num]);

/*
 * Increment the statistical counters. use raw_cpu_inc() because of lower
 * overhead and we don't care if we loose the occasional update.
 */
static inline void __lockevent_inc(enum lock_events event, bool cond)
{ … }

#define lockevent_inc(ev) …
#define lockevent_cond_inc(ev, c) …

static inline void __lockevent_add(enum lock_events event, int inc)
{ … }

#define lockevent_add(ev, c) …

#else  /* CONFIG_LOCK_EVENT_COUNTS */

#define lockevent_inc …
#define lockevent_add …
#define lockevent_cond_inc …

#endif /* CONFIG_LOCK_EVENT_COUNTS */

ssize_t lockevent_read(struct file *file, char __user *user_buf,
		       size_t count, loff_t *ppos);

#endif /* __LOCKING_LOCK_EVENTS_H */