Hi,
This patch allows swsusp to freeze processes successfully under heavy load
by freezing userspace processes before kernel threads.
[Thanks to Nigel Cunningham <[email protected]> for suggesting the
way to go.]
Please consider for applying.
Greetings,
Rafael
Signed-off-by: Rafael J. Wysocki <[email protected]>
Acked-by: Pavel Machek <[email protected]>
kernel/power/disk.c | 1
kernel/power/process.c | 61 ++++++++++++++++++++++++++++++++++++-------------
kernel/power/user.c | 1
3 files changed, 46 insertions(+), 17 deletions(-)
Index: linux-2.6.16-rc1-mm5/kernel/power/process.c
===================================================================
--- linux-2.6.16-rc1-mm5.orig/kernel/power/process.c
+++ linux-2.6.16-rc1-mm5/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;
}
Index: linux-2.6.16-rc1-mm5/kernel/power/disk.c
===================================================================
--- linux-2.6.16-rc1-mm5.orig/kernel/power/disk.c
+++ linux-2.6.16-rc1-mm5/kernel/power/disk.c
@@ -73,7 +73,6 @@ static int prepare_processes(void)
int error;
pm_prepare_console();
- sys_sync();
disable_nonboot_cpus();
if (freeze_processes()) {
Index: linux-2.6.16-rc1-mm5/kernel/power/user.c
===================================================================
--- linux-2.6.16-rc1-mm5.orig/kernel/power/user.c
+++ linux-2.6.16-rc1-mm5/kernel/power/user.c
@@ -137,7 +137,6 @@ static int snapshot_ioctl(struct inode *
case SNAPSHOT_FREEZE:
if (data->frozen)
break;
- sys_sync();
down(&pm_sem);
pm_prepare_console();
disable_nonboot_cpus();
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
