linux/kernel/locking/qspinlock_stat.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 *
 * Authors: Waiman Long <[email protected]>
 */

#include "lock_events.h"

#ifdef CONFIG_LOCK_EVENT_COUNTS
#ifdef CONFIG_PARAVIRT_SPINLOCKS
/*
 * Collect pvqspinlock locking event counts
 */
#include <linux/sched.h>
#include <linux/sched/clock.h>
#include <linux/fs.h>

#define EVENT_COUNT(ev) …

/*
 * PV specific per-cpu counter
 */
static DEFINE_PER_CPU(u64, pv_kick_time);

/*
 * Function to read and return the PV qspinlock counts.
 *
 * The following counters are handled specially:
 * 1. pv_latency_kick
 *    Average kick latency (ns) = pv_latency_kick/pv_kick_unlock
 * 2. pv_latency_wake
 *    Average wake latency (ns) = pv_latency_wake/pv_kick_wake
 * 3. pv_hash_hops
 *    Average hops/hash = pv_hash_hops/pv_kick_unlock
 */
ssize_t lockevent_read(struct file *file, char __user *user_buf,
		       size_t count, loff_t *ppos)
{ … }

/*
 * PV hash hop count
 */
static inline void lockevent_pv_hop(int hopcnt)
{ … }

/*
 * Replacement function for pv_kick()
 */
static inline void __pv_kick(int cpu)
{ … }

/*
 * Replacement function for pv_wait()
 */
static inline void __pv_wait(u8 *ptr, u8 val)
{ … }

#define pv_kick(c) …
#define pv_wait(p, v) …

#endif /* CONFIG_PARAVIRT_SPINLOCKS */

#else /* CONFIG_LOCK_EVENT_COUNTS */

static inline void lockevent_pv_hop(int hopcnt)	{ }

#endif /* CONFIG_LOCK_EVENT_COUNTS */