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![Rafael J. Wysocki](/assets/img/avatar_default.png)
Revert commit eed4d47efe
(ACPI / sleep: Ignore spurious SCI wakeups
from suspend-to-idle) as it turned out to be premature and triggered
a number of different issues on various systems.
That includes, but is not limited to, premature suspend-to-RAM aborts
on Dell XPS 13 (9343) reported by Dominik.
The issue the commit in question attempted to address is real and
will need to be taken care of going forward, but evidently more work
is needed for this purpose.
Reported-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
241 lines
5.5 KiB
C
241 lines
5.5 KiB
C
/*
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* drivers/power/process.c - Functions for starting/stopping processes on
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* suspend transitions.
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*
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* Originally from swsusp.
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*/
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#undef DEBUG
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#include <linux/interrupt.h>
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#include <linux/oom.h>
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#include <linux/suspend.h>
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#include <linux/module.h>
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#include <linux/sched/debug.h>
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#include <linux/sched/task.h>
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#include <linux/syscalls.h>
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#include <linux/freezer.h>
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#include <linux/delay.h>
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#include <linux/workqueue.h>
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#include <linux/kmod.h>
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#include <trace/events/power.h>
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/*
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* Timeout for stopping processes
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*/
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unsigned int __read_mostly freeze_timeout_msecs = 20 * MSEC_PER_SEC;
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static int try_to_freeze_tasks(bool user_only)
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{
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struct task_struct *g, *p;
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unsigned long end_time;
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unsigned int todo;
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bool wq_busy = false;
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ktime_t start, end, elapsed;
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unsigned int elapsed_msecs;
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bool wakeup = false;
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int sleep_usecs = USEC_PER_MSEC;
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start = ktime_get_boottime();
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end_time = jiffies + msecs_to_jiffies(freeze_timeout_msecs);
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if (!user_only)
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freeze_workqueues_begin();
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while (true) {
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todo = 0;
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read_lock(&tasklist_lock);
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for_each_process_thread(g, p) {
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if (p == current || !freeze_task(p))
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continue;
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if (!freezer_should_skip(p))
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todo++;
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}
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read_unlock(&tasklist_lock);
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if (!user_only) {
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wq_busy = freeze_workqueues_busy();
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todo += wq_busy;
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}
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if (!todo || time_after(jiffies, end_time))
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break;
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if (pm_wakeup_pending()) {
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wakeup = true;
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break;
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}
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/*
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* We need to retry, but first give the freezing tasks some
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* time to enter the refrigerator. Start with an initial
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* 1 ms sleep followed by exponential backoff until 8 ms.
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*/
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usleep_range(sleep_usecs / 2, sleep_usecs);
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if (sleep_usecs < 8 * USEC_PER_MSEC)
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sleep_usecs *= 2;
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}
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end = ktime_get_boottime();
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elapsed = ktime_sub(end, start);
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elapsed_msecs = ktime_to_ms(elapsed);
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if (todo) {
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pr_cont("\n");
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pr_err("Freezing of tasks %s after %d.%03d seconds "
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"(%d tasks refusing to freeze, wq_busy=%d):\n",
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wakeup ? "aborted" : "failed",
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elapsed_msecs / 1000, elapsed_msecs % 1000,
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todo - wq_busy, wq_busy);
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if (wq_busy)
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show_workqueue_state();
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if (!wakeup) {
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read_lock(&tasklist_lock);
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for_each_process_thread(g, p) {
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if (p != current && !freezer_should_skip(p)
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&& freezing(p) && !frozen(p))
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sched_show_task(p);
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}
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read_unlock(&tasklist_lock);
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}
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} else {
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pr_cont("(elapsed %d.%03d seconds) ", elapsed_msecs / 1000,
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elapsed_msecs % 1000);
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}
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return todo ? -EBUSY : 0;
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}
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/**
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* freeze_processes - Signal user space processes to enter the refrigerator.
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* The current thread will not be frozen. The same process that calls
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* freeze_processes must later call thaw_processes.
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*
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* On success, returns 0. On failure, -errno and system is fully thawed.
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*/
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int freeze_processes(void)
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{
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int error;
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error = __usermodehelper_disable(UMH_FREEZING);
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if (error)
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return error;
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/* Make sure this task doesn't get frozen */
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current->flags |= PF_SUSPEND_TASK;
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if (!pm_freezing)
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atomic_inc(&system_freezing_cnt);
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pm_wakeup_clear();
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pr_info("Freezing user space processes ... ");
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pm_freezing = true;
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error = try_to_freeze_tasks(true);
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if (!error) {
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__usermodehelper_set_disable_depth(UMH_DISABLED);
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pr_cont("done.");
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}
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pr_cont("\n");
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BUG_ON(in_atomic());
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/*
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* Now that the whole userspace is frozen we need to disbale
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* the OOM killer to disallow any further interference with
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* killable tasks. There is no guarantee oom victims will
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* ever reach a point they go away we have to wait with a timeout.
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*/
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if (!error && !oom_killer_disable(msecs_to_jiffies(freeze_timeout_msecs)))
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error = -EBUSY;
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if (error)
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thaw_processes();
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return error;
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}
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/**
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* freeze_kernel_threads - Make freezable kernel threads go to the refrigerator.
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*
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* On success, returns 0. On failure, -errno and only the kernel threads are
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* thawed, so as to give a chance to the caller to do additional cleanups
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* (if any) before thawing the userspace tasks. So, it is the responsibility
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* of the caller to thaw the userspace tasks, when the time is right.
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*/
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int freeze_kernel_threads(void)
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{
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int error;
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pr_info("Freezing remaining freezable tasks ... ");
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pm_nosig_freezing = true;
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error = try_to_freeze_tasks(false);
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if (!error)
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pr_cont("done.");
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pr_cont("\n");
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BUG_ON(in_atomic());
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if (error)
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thaw_kernel_threads();
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return error;
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}
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void thaw_processes(void)
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{
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struct task_struct *g, *p;
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struct task_struct *curr = current;
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trace_suspend_resume(TPS("thaw_processes"), 0, true);
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if (pm_freezing)
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atomic_dec(&system_freezing_cnt);
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pm_freezing = false;
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pm_nosig_freezing = false;
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oom_killer_enable();
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pr_info("Restarting tasks ... ");
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__usermodehelper_set_disable_depth(UMH_FREEZING);
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thaw_workqueues();
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read_lock(&tasklist_lock);
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for_each_process_thread(g, p) {
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/* No other threads should have PF_SUSPEND_TASK set */
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WARN_ON((p != curr) && (p->flags & PF_SUSPEND_TASK));
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__thaw_task(p);
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}
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read_unlock(&tasklist_lock);
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WARN_ON(!(curr->flags & PF_SUSPEND_TASK));
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curr->flags &= ~PF_SUSPEND_TASK;
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usermodehelper_enable();
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schedule();
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pr_cont("done.\n");
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trace_suspend_resume(TPS("thaw_processes"), 0, false);
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}
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void thaw_kernel_threads(void)
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{
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struct task_struct *g, *p;
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pm_nosig_freezing = false;
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pr_info("Restarting kernel threads ... ");
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thaw_workqueues();
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read_lock(&tasklist_lock);
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for_each_process_thread(g, p) {
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if (p->flags & (PF_KTHREAD | PF_WQ_WORKER))
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__thaw_task(p);
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}
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read_unlock(&tasklist_lock);
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schedule();
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pr_cont("done.\n");
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}
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