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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /kernel/power/process.c
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'kernel/power/process.c')
-rw-r--r--kernel/power/process.c220
1 files changed, 220 insertions, 0 deletions
diff --git a/kernel/power/process.c b/kernel/power/process.c
new file mode 100644
index 00000000..19db29f6
--- /dev/null
+++ b/kernel/power/process.c
@@ -0,0 +1,220 @@
+/*
+ * 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/syscalls.h>
+#include <linux/freezer.h>
+#include <linux/delay.h>
+#include <linux/workqueue.h>
+#include <linux/kmod.h>
+
+/*
+ * Timeout for stopping processes
+ */
+#define TIMEOUT (20 * HZ)
+
+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;
+ struct timeval start, end;
+ u64 elapsed_csecs64;
+ unsigned int elapsed_csecs;
+ bool wakeup = false;
+
+ do_gettimeofday(&start);
+
+ end_time = jiffies + TIMEOUT;
+
+ if (!user_only)
+ freeze_workqueues_begin();
+
+ while (true) {
+ todo = 0;
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ if (p == current || !freeze_task(p))
+ continue;
+
+ /*
+ * Now that we've done set_freeze_flag, don't
+ * perturb a task in TASK_STOPPED or TASK_TRACED.
+ * It is "frozen enough". If the task does wake
+ * up, it will immediately call try_to_freeze.
+ *
+ * Because freeze_task() goes through p's scheduler lock, it's
+ * guaranteed that TASK_STOPPED/TRACED -> TASK_RUNNING
+ * transition can't race with task state testing here.
+ */
+ if (!task_is_stopped_or_traced(p) &&
+ !freezer_should_skip(p))
+ todo++;
+ } while_each_thread(g, p);
+ read_unlock(&tasklist_lock);
+
+ if (!user_only) {
+ wq_busy = freeze_workqueues_busy();
+ todo += wq_busy;
+ }
+
+ if (!todo || time_after(jiffies, end_time))
+ break;
+
+ if (pm_wakeup_pending()) {
+ wakeup = true;
+ break;
+ }
+
+ /*
+ * We need to retry, but first give the freezing tasks some
+ * time to enter the regrigerator.
+ */
+ msleep(10);
+ }
+
+ do_gettimeofday(&end);
+ elapsed_csecs64 = timeval_to_ns(&end) - timeval_to_ns(&start);
+ do_div(elapsed_csecs64, NSEC_PER_SEC / 100);
+ elapsed_csecs = elapsed_csecs64;
+
+ if (todo) {
+ printk("\n");
+ printk(KERN_ERR "Freezing of tasks %s after %d.%02d seconds "
+ "(%d tasks refusing to freeze, wq_busy=%d):\n",
+ wakeup ? "aborted" : "failed",
+ elapsed_csecs / 100, elapsed_csecs % 100,
+ todo - wq_busy, wq_busy);
+
+ if (!wakeup) {
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ if (p != current && !freezer_should_skip(p)
+ && freezing(p) && !frozen(p))
+ sched_show_task(p);
+ } while_each_thread(g, p);
+ read_unlock(&tasklist_lock);
+ }
+ } else {
+ printk("(elapsed %d.%02d seconds) ", elapsed_csecs / 100,
+ elapsed_csecs % 100);
+ }
+
+ return todo ? -EBUSY : 0;
+}
+
+/**
+ * freeze_processes - Signal user space processes to enter the refrigerator.
+ *
+ * On success, returns 0. On failure, -errno and system is fully thawed.
+ */
+int freeze_processes(void)
+{
+ int error;
+
+ error = __usermodehelper_disable(UMH_FREEZING);
+ if (error)
+ return error;
+
+ if (!pm_freezing)
+ atomic_inc(&system_freezing_cnt);
+
+ printk("Freezing user space processes ... ");
+ pm_freezing = true;
+ error = try_to_freeze_tasks(true);
+ if (!error) {
+ printk("done.");
+ __usermodehelper_set_disable_depth(UMH_DISABLED);
+ oom_killer_disable();
+ }
+ printk("\n");
+ BUG_ON(in_atomic());
+
+ if (error)
+ thaw_processes();
+ return error;
+}
+
+/**
+ * freeze_kernel_threads - Make freezable kernel threads go to the refrigerator.
+ *
+ * On success, returns 0. On failure, -errno and only the kernel threads are
+ * thawed, so as to give a chance to the caller to do additional cleanups
+ * (if any) before thawing the userspace tasks. So, it is the responsibility
+ * of the caller to thaw the userspace tasks, when the time is right.
+ */
+int freeze_kernel_threads(void)
+{
+ int error;
+
+ printk("Freezing remaining freezable tasks ... ");
+ pm_nosig_freezing = true;
+ error = try_to_freeze_tasks(false);
+ if (!error)
+ printk("done.");
+
+ printk("\n");
+ BUG_ON(in_atomic());
+
+ if (error)
+ thaw_kernel_threads();
+ return error;
+}
+
+void thaw_processes(void)
+{
+ struct task_struct *g, *p;
+
+ if (pm_freezing)
+ atomic_dec(&system_freezing_cnt);
+ pm_freezing = false;
+ pm_nosig_freezing = false;
+
+ oom_killer_enable();
+
+ printk("Restarting tasks ... ");
+
+ thaw_workqueues();
+
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ __thaw_task(p);
+ } while_each_thread(g, p);
+ read_unlock(&tasklist_lock);
+
+ usermodehelper_enable();
+
+ schedule();
+ printk("done.\n");
+}
+
+void thaw_kernel_threads(void)
+{
+ struct task_struct *g, *p;
+
+ pm_nosig_freezing = false;
+ printk("Restarting kernel threads ... ");
+
+ thaw_workqueues();
+
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ if (p->flags & (PF_KTHREAD | PF_WQ_WORKER))
+ __thaw_task(p);
+ } while_each_thread(g, p);
+ read_unlock(&tasklist_lock);
+
+ schedule();
+ printk("done.\n");
+}