aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/power/process.c
diff options
context:
space:
mode:
authorRafael J. Wysocki <rjw@sisk.pl>2006-03-23 03:00:04 -0800
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-23 07:38:08 -0800
commit02aaeb9b952f30b1ad6284d5d45be02030f679db (patch)
tree6577fcc544d34fbc9951be5dc1089ac227440573 /kernel/power/process.c
parent6e1819d615f24ce0726a7d0bd3dd0152d7b21654 (diff)
[PATCH] swsusp: freeze user space processes first
Allow swsusp to freeze processes successfully under heavy load by freezing userspace processes before kernel threads. [Thanks to Nigel Cunningham <nigel@suspend2.net> for suggesting the way to go.] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@suse.cz> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/power/process.c')
-rw-r--r--kernel/power/process.c61
1 files changed, 46 insertions, 15 deletions
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 02a1b3a9fa90..8ac7c35fad77 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -12,11 +12,12 @@
#include <linux/interrupt.h>
#include <linux/suspend.h>
#include <linux/module.h>
+#include <linux/syscalls.h>
/*
* Timeout for stopping processes
*/
-#define TIMEOUT (6 * HZ)
+#define TIMEOUT (20 * HZ)
static inline int freezeable(struct task_struct * p)
@@ -54,38 +55,62 @@ void refrigerator(void)
current->state = save;
}
+static inline void freeze_process(struct task_struct *p)
+{
+ unsigned long flags;
+
+ if (!freezing(p)) {
+ freeze(p);
+ spin_lock_irqsave(&p->sighand->siglock, flags);
+ signal_wake_up(p, 0);
+ spin_unlock_irqrestore(&p->sighand->siglock, flags);
+ }
+}
+
/* 0 = success, else # of processes that we failed to stop */
int freeze_processes(void)
{
- int todo;
+ int todo, nr_user, user_frozen;
unsigned long start_time;
struct task_struct *g, *p;
unsigned long flags;
printk( "Stopping tasks: " );
start_time = jiffies;
+ user_frozen = 0;
do {
- todo = 0;
+ nr_user = todo = 0;
read_lock(&tasklist_lock);
do_each_thread(g, p) {
if (!freezeable(p))
continue;
if (frozen(p))
continue;
-
- freeze(p);
- spin_lock_irqsave(&p->sighand->siglock, flags);
- signal_wake_up(p, 0);
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
- todo++;
+ if (p->mm && !(p->flags & PF_BORROWED_MM)) {
+ /* The task is a user-space one.
+ * Freeze it unless there's a vfork completion
+ * pending
+ */
+ if (!p->vfork_done)
+ freeze_process(p);
+ nr_user++;
+ } else {
+ /* Freeze only if the user space is frozen */
+ if (user_frozen)
+ freeze_process(p);
+ todo++;
+ }
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
+ todo += nr_user;
+ if (!user_frozen && !nr_user) {
+ sys_sync();
+ start_time = jiffies;
+ }
+ user_frozen = !nr_user;
yield(); /* Yield is okay here */
- if (todo && time_after(jiffies, start_time + TIMEOUT)) {
- printk( "\n" );
- printk(KERN_ERR " stopping tasks timed out (%d tasks remaining)\n", todo );
+ if (todo && time_after(jiffies, start_time + TIMEOUT))
break;
- }
} while(todo);
/* This does not unfreeze processes that are already frozen
@@ -94,8 +119,14 @@ int freeze_processes(void)
* but it cleans up leftover PF_FREEZE requests.
*/
if (todo) {
+ printk( "\n" );
+ printk(KERN_ERR " stopping tasks timed out "
+ "after %d seconds (%d tasks remaining):\n",
+ TIMEOUT / HZ, todo);
read_lock(&tasklist_lock);
- do_each_thread(g, p)
+ do_each_thread(g, p) {
+ if (freezeable(p) && !frozen(p))
+ printk(KERN_ERR " %s\n", p->comm);
if (freezing(p)) {
pr_debug(" clean up: %s\n", p->comm);
p->flags &= ~PF_FREEZE;
@@ -103,7 +134,7 @@ int freeze_processes(void)
recalc_sigpending_tsk(p);
spin_unlock_irqrestore(&p->sighand->siglock, flags);
}
- while_each_thread(g, p);
+ } while_each_thread(g, p);
read_unlock(&tasklist_lock);
return todo;
}

Privacy Policy