linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * drivers/power/process.c - Functions for starting/stopping processes on 

 *                           suspend transitions.

 *

 * Originally from swsusp.

 */

​

​

#undef DEBUG

​

#include <linux/interrupt.h>

#include <linux/oom.h>

#include <linux/suspend.h>

#include <linux/module.h>

#include <linux/sched/debug.h>

#include <linux/sched/task.h>

#include <linux/syscalls.h>

#include <linux/freezer.h>

#include <linux/delay.h>

#include <linux/workqueue.h>

#include <linux/kmod.h>

#include <trace/events/power.h>

#include <linux/cpuset.h>

​

/*

 * Timeout for stopping processes

 */

unsigned int __read_mostly freeze_timeout_msecs = 20 * MSEC_PER_SEC;

​

static int try_to_freeze_tasks(bool user_only)

{

    struct task_struct *g, *p;

    unsigned long end_time;

    unsigned int todo;

    bool wq_busy = false;

    ktime_t start, end, elapsed;

    unsigned int elapsed_msecs;

    bool wakeup = false;

    int sleep_usecs = USEC_PER_MSEC;

​

    start = ktime_get_boottime();

​

    end_time = jiffies + msecs_to_jiffies(freeze_timeout_msecs);

​

    if (!user_only)

        freeze_workqueues_begin();

​

    while (true) {

        todo = 0;

        read_lock(&tasklist_lock);

        for_each_process_thread(g, p) {

            if (p == current || !freeze_task(p))

                continue;

​

            if (!freezer_should_skip(p))

                todo++;

        }

        read_unlock(&tasklist_lock);

​

        if (!user_only) {

            wq_busy = freeze_workqueues_busy();

            todo += wq_busy;