[Suspend2][ 2/2] [Suspend2] Freezer upgrade.
From: Nigel Cunningham
Date: Mon Jun 26 2006 - 12:38:04 EST
This patch represents the Suspend2 upgrades to the freezer implementation.
Due to recent changes in the vanilla version, I should be able to greatly
reduce the size of this patch. TODO.
Signed-off-by: Nigel Cunningham <nigel@xxxxxxxxxxxx>
include/linux/freezer.h | 29 +++++++++++
include/linux/sched.h | 4 +
include/linux/suspend.h | 5 ++
kernel/kmod.c | 4 +
kernel/power/disk.c | 5 +-
kernel/power/main.c | 5 +-
kernel/power/process.c | 127 ++++++++++++++++++++++++++++++++++++++++-------
kernel/power/swsusp.c | 5 ++
kernel/power/user.c | 7 +--
9 files changed, 164 insertions(+), 27 deletions(-)
diff --git a/include/linux/freezer.h b/include/linux/freezer.h
new file mode 100644
index 0000000..43ef3b2
--- /dev/null
+++ b/include/linux/freezer.h
@@ -0,0 +1,29 @@
+/* Freezer declarations */
+
+#define FREEZER_ON 0
+#define ABORT_FREEZING 1
+#define FREEZING_COMPLETE 2
+
+#define FREEZER_KERNEL_THREADS 0
+#define FREEZER_ALL_THREADS 1
+
+#ifdef CONFIG_PM
+extern unsigned long freezer_state;
+
+#define test_freezer_state(bit) test_bit(bit, &freezer_state)
+#define set_freezer_state(bit) set_bit(bit, &freezer_state)
+#define clear_freezer_state(bit) clear_bit(bit, &freezer_state)
+
+#define freezer_is_on() (test_freezer_state(FREEZER_ON))
+
+extern void do_freeze_process(struct notifier_block *nl);
+
+#else
+
+#define test_freezer_state(bit) (0)
+#define set_freezer_state(bit) do { } while(0)
+#define clear_freezer_state(bit) do { } while(0)
+
+#define freezer_is_on() (0)
+
+#endif
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 267f152..b6d96ab 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1452,7 +1452,7 @@ static inline void frozen_process(struct
extern void refrigerator(void);
extern int freeze_processes(void);
-extern void thaw_processes(void);
+extern void thaw_processes(int which_threads);
static inline int try_to_freeze(void)
{
@@ -1471,7 +1471,7 @@ static inline void frozen_process(struct
static inline void refrigerator(void) {}
static inline int freeze_processes(void) { BUG(); return 0; }
-static inline void thaw_processes(void) {}
+static inline void thaw_processes(int which_threads) {}
static inline int try_to_freeze(void) { return 0; }
diff --git a/include/linux/suspend.h b/include/linux/suspend.h
index 96e31aa..b128fd2 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -8,6 +8,7 @@
#include <linux/notifier.h>
#include <linux/init.h>
#include <linux/pm.h>
+#include <linux/suspend2.h>
/* page backup entry */
typedef struct pbe {
@@ -45,6 +46,8 @@ extern int software_suspend(void);
#if defined(CONFIG_VT) && defined(CONFIG_VT_CONSOLE)
extern int pm_prepare_console(void);
extern void pm_restore_console(void);
+extern int freeze_processes(void);
+extern void thaw_processes(int which_threads);
#else
static inline int pm_prepare_console(void) { return 0; }
static inline void pm_restore_console(void) {}
@@ -55,6 +58,8 @@ static inline int software_suspend(void)
printk("Warning: fake suspend called\n");
return -EPERM;
}
+static inline int freeze_processes(void) { return 0; }
+static inline void thaw_processes(int which_threads) { }
#endif /* CONFIG_PM */
#ifdef CONFIG_SUSPEND_SMP
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 20a997c..b792b32 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -36,6 +36,7 @@
#include <linux/mount.h>
#include <linux/kernel.h>
#include <linux/init.h>
+#include <linux/freezer.h>
#include <asm/uaccess.h>
extern int max_threads;
@@ -249,6 +250,9 @@ int call_usermodehelper_keys(char *path,
if (!khelper_wq)
return -EBUSY;
+ if (freezer_is_on())
+ return 0;
+
if (path[0] == '\0')
return 0;
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
index 81d4d98..a2463e3 100644
--- a/kernel/power/disk.c
+++ b/kernel/power/disk.c
@@ -10,6 +10,7 @@
*/
#include <linux/suspend.h>
+#include <linux/freezer.h>
#include <linux/syscalls.h>
#include <linux/reboot.h>
#include <linux/string.h>
@@ -83,7 +84,7 @@ static int prepare_processes(void)
if (!(error = swsusp_shrink_memory()))
return 0;
thaw:
- thaw_processes();
+ thaw_processes(FREEZER_ALL_THREADS);
enable_nonboot_cpus();
pm_restore_console();
return error;
@@ -92,7 +93,7 @@ thaw:
static void unprepare_processes(void)
{
platform_finish();
- thaw_processes();
+ thaw_processes(FREEZER_ALL_THREADS);
enable_nonboot_cpus();
pm_restore_console();
}
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 0a907f0..8413db2 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -9,6 +9,7 @@
*/
#include <linux/suspend.h>
+#include <linux/freezer.h>
#include <linux/kobject.h>
#include <linux/string.h>
#include <linux/delay.h>
@@ -96,7 +97,7 @@ static int suspend_prepare(suspend_state
if (pm_ops->finish)
pm_ops->finish(state);
Thaw:
- thaw_processes();
+ thaw_processes(FREEZER_ALL_THREADS);
Enable_cpu:
enable_nonboot_cpus();
pm_restore_console();
@@ -135,7 +136,7 @@ static void suspend_finish(suspend_state
{
device_resume();
resume_console();
- thaw_processes();
+ thaw_processes(FREEZER_ALL_THREADS);
enable_nonboot_cpus();
if (pm_ops && pm_ops->finish)
pm_ops->finish(state);
diff --git a/kernel/power/process.c b/kernel/power/process.c
index b2a5f67..020895d 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -5,7 +5,6 @@
* Originally from swsusp.
*/
-
#undef DEBUG
#include <linux/smp_lock.h>
@@ -13,12 +12,72 @@
#include <linux/suspend.h>
#include <linux/module.h>
#include <linux/syscalls.h>
+#include <linux/buffer_head.h>
+#include <linux/freezer.h>
+
+unsigned long freezer_state = 0;
+
+#ifdef CONFIG_PM_DEBUG
+#define freezer_message(msg, a...) do { printk(msg, ##a); } while(0)
+#else
+#define freezer_message(msg, a...) do { } while(0)
+#endif
/*
* Timeout for stopping processes
*/
#define TIMEOUT (20 * HZ)
+struct frozen_fs
+{
+ struct list_head fsb_list;
+ struct super_block *sb;
+};
+
+LIST_HEAD(frozen_fs_list);
+
+void freezer_make_fses_rw(void)
+{
+ struct frozen_fs *fs, *next_fs;
+
+ list_for_each_entry_safe(fs, next_fs, &frozen_fs_list, fsb_list) {
+ thaw_bdev(fs->sb->s_bdev, fs->sb);
+
+ list_del(&fs->fsb_list);
+ kfree(fs);
+ }
+}
+
+/*
+ * Done after userspace is frozen, so there should be no danger of
+ * fses being unmounted while we're in here.
+ */
+int freezer_make_fses_ro(void)
+{
+ struct frozen_fs *fs;
+ struct super_block *sb;
+
+ /* Generate the list */
+ list_for_each_entry(sb, &super_blocks, s_list) {
+ if (!sb->s_root || !sb->s_bdev ||
+ (sb->s_frozen == SB_FREEZE_TRANS) ||
+ (sb->s_flags & MS_RDONLY))
+ continue;
+
+ fs = kmalloc(sizeof(struct frozen_fs), GFP_ATOMIC);
+ fs->sb = sb;
+ list_add_tail(&fs->fsb_list, &frozen_fs_list);
+ };
+
+ /* Do the freezing in reverse order so filesystems dependant
+ * upon others are frozen in the right order. (Eg loopback
+ * on ext3). */
+ list_for_each_entry_reverse(fs, &frozen_fs_list, fsb_list)
+ freeze_bdev(fs->sb->s_bdev);
+
+ return 0;
+}
+
static inline int freezeable(struct task_struct * p)
{
@@ -39,7 +98,7 @@ void refrigerator(void)
long save;
save = current->state;
pr_debug("%s entered refrigerator\n", current->comm);
- printk("=");
+ freezer_message("=");
frozen_process(current);
spin_lock_irq(¤t->sighand->siglock);
@@ -74,9 +133,13 @@ int freeze_processes(void)
struct task_struct *g, *p;
unsigned long flags;
- printk( "Stopping tasks: " );
+ user_frozen = test_freezer_state(FREEZER_ON);
+
+ if (!user_frozen)
+ set_freezer_state(FREEZER_ON);
+
+ freezer_message( "Stopping tasks: " );
start_time = jiffies;
- user_frozen = 0;
do {
nr_user = todo = 0;
read_lock(&tasklist_lock);
@@ -103,8 +166,10 @@ int freeze_processes(void)
read_unlock(&tasklist_lock);
todo += nr_user;
if (!user_frozen && !nr_user) {
- sys_sync();
+ freezer_message("Freezing bdevs... ");
+ freezer_make_fses_ro();
start_time = jiffies;
+ freezer_message("Freezing kernel threads... ");
}
user_frozen = !nr_user;
yield(); /* Yield is okay here */
@@ -118,14 +183,14 @@ int freeze_processes(void)
* but it cleans up leftover PF_FREEZE requests.
*/
if (todo) {
- printk( "\n" );
- printk(KERN_ERR " stopping tasks timed out "
+ freezer_message( "\n" );
+ freezer_message(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) {
if (freezeable(p) && !frozen(p))
- printk(KERN_ERR " %s\n", p->comm);
+ freezer_message(KERN_ERR " %s\n", p->comm);
if (freezing(p)) {
pr_debug(" clean up: %s\n", p->comm);
p->flags &= ~PF_FREEZE;
@@ -138,27 +203,53 @@ int freeze_processes(void)
return todo;
}
- printk( "|\n" );
+ freezer_message( "|\n" );
BUG_ON(in_atomic());
+
+ set_freezer_state(FREEZING_COMPLETE);
+
return 0;
}
-void thaw_processes(void)
+void thaw_processes(int all)
{
struct task_struct *g, *p;
+ int pass = 0; /* Start on kernel space */
+
+ if (!test_freezer_state(FREEZER_ON))
+ return;
+
+ if (!test_freezer_state(FREEZING_COMPLETE))
+ pass++;
+
+ clear_freezer_state(FREEZING_COMPLETE);
- printk( "Restarting tasks..." );
+ freezer_message( "Restarting tasks..." );
read_lock(&tasklist_lock);
- do_each_thread(g, p) {
- if (!freezeable(p))
- continue;
- if (!thaw_process(p))
- printk(KERN_INFO " Strange, %s not stopped\n", p->comm );
- } while_each_thread(g, p);
+ do {
+ if (pass) {
+ read_unlock(&tasklist_lock);
+ freezer_make_fses_rw();
+ read_lock(&tasklist_lock);
+ }
+
+ do_each_thread(g, p) {
+ int is_user = !!(p->mm && !(p->flags & PF_BORROWED_MM));
+ if (!freezeable(p) || (is_user != pass))
+ continue;
+ if (!thaw_process(p))
+ freezer_message(KERN_INFO " Strange, %s not stopped\n", p->comm );
+ } while_each_thread(g, p);
+
+ pass++;
+ } while(pass < 2 && all);
read_unlock(&tasklist_lock);
schedule();
- printk( " done\n" );
+ freezer_message( " done\n" );
+
+ if (all)
+ clear_freezer_state(FREEZER_ON);
}
EXPORT_SYMBOL(refrigerator);
diff --git a/kernel/power/swsusp.c b/kernel/power/swsusp.c
index c4016cb..64acda1 100644
--- a/kernel/power/swsusp.c
+++ b/kernel/power/swsusp.c
@@ -49,6 +49,7 @@
#include <linux/bootmem.h>
#include <linux/syscalls.h>
#include <linux/highmem.h>
+#include <linux/freezer.h>
#include "power.h"
@@ -184,6 +185,8 @@ int swsusp_shrink_memory(void)
unsigned int i = 0;
char *p = "-\\|/";
+ thaw_processes(FREEZER_KERNEL_THREADS);
+
printk("Shrinking memory... ");
do {
size = 2 * count_highmem_pages();
@@ -207,6 +210,8 @@ int swsusp_shrink_memory(void)
} while (tmp > 0);
printk("\bdone (%lu pages freed)\n", pages);
+ freeze_processes();
+
return 0;
}
diff --git a/kernel/power/user.c b/kernel/power/user.c
index 3f1539f..10d5c9b 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -19,6 +19,7 @@
#include <linux/swapops.h>
#include <linux/pm.h>
#include <linux/fs.h>
+#include <linux/freezer.h>
#include <asm/uaccess.h>
@@ -75,7 +76,7 @@ static int snapshot_release(struct inode
free_bitmap(data->bitmap);
if (data->frozen) {
down(&pm_sem);
- thaw_processes();
+ thaw_processes(FREEZER_ALL_THREADS);
enable_nonboot_cpus();
up(&pm_sem);
}
@@ -141,7 +142,7 @@ static int snapshot_ioctl(struct inode *
down(&pm_sem);
disable_nonboot_cpus();
if (freeze_processes()) {
- thaw_processes();
+ thaw_processes(FREEZER_ALL_THREADS);
enable_nonboot_cpus();
error = -EBUSY;
}
@@ -154,7 +155,7 @@ static int snapshot_ioctl(struct inode *
if (!data->frozen)
break;
down(&pm_sem);
- thaw_processes();
+ thaw_processes(FREEZER_ALL_THREADS);
enable_nonboot_cpus();
up(&pm_sem);
data->frozen = 0;
--
Nigel Cunningham nigel at suspend2 dot net
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