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SubjectRe: [PATCH -mm 1/2] Separate freezer from PM code
Date
On Friday, 27 April 2007 18:25, Jeremy Fitzhardinge wrote:
> Rafael J. Wysocki wrote:
> > --- linux-2.6.21-rc7-mm2.orig/arch/x86_64/Kconfig 2007-04-27 01:22:33.000000000 +0200
> > +++ linux-2.6.21-rc7-mm2/arch/x86_64/Kconfig 2007-04-27 01:33:22.000000000 +0200
> > @@ -703,6 +703,14 @@ config GENERIC_PENDING_IRQ
> > depends on GENERIC_HARDIRQS && SMP
> > default y
> >
> > +#
> > +# Use the tasks freezer
> > +#
> > +config FREEZER
> > + bool
> > + default y
> > + depends on PM || KPROBES
> > +
> >
>
> Shouldn't PM and KPROBES "select" FREEZER if they want it? That way its
> easier for other future users of FREEZER to do so without having to
> change the Kconfig here (and the other 23000 Kconfigs).

Makes sense. Please have a look at the updated patch below.

Sam, does this one look better to you?

---
From: Rafael J. Wysocki <rjw@sisk.pl>
Now that the freezer is used by kprobes, it is no longer a PM-specific piece of
code. Move the freezer code out of kernel/power and introduce the
CONFIG_FREEZER option that will be chosen automatically if PM or KPROBES is
set.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
---
arch/arm/Kconfig | 4
arch/avr32/Kconfig | 4
arch/avr32/Kconfig.debug | 1
arch/blackfin/Kconfig | 4
arch/frv/Kconfig | 4
arch/i386/Kconfig | 5
arch/ia64/Kconfig | 5
arch/mips/Kconfig | 4
arch/powerpc/Kconfig | 5
arch/ppc/Kconfig | 4
arch/s390/Kconfig | 5
arch/sh/Kconfig | 4
arch/sparc64/Kconfig | 5
arch/x86_64/Kconfig | 5
include/linux/freezer.h | 2
kernel/Makefile | 1
kernel/freezer.c | 236 +++++++++++++++++++++++++++++++++++++++++++++++
kernel/kprobes.c | 2
kernel/power/Kconfig | 1
kernel/power/Makefile | 2
kernel/power/process.c | 236 -----------------------------------------------
21 files changed, 300 insertions(+), 239 deletions(-)
Index: linux-2.6.21-rc7-mm2/arch/x86_64/Kconfig
===================================================================
--- linux-2.6.21-rc7-mm2.orig/arch/x86_64/Kconfig 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/arch/x86_64/Kconfig 2007-04-27 21:56:01.000000000 +0200
@@ -129,6 +129,10 @@ config ARCH_HAS_ILOG2_U64
bool
default n

+config FREEZER
+ bool
+ default n
+
source "init/Kconfig"


@@ -791,6 +795,7 @@ source "arch/x86_64/oprofile/Kconfig"
config KPROBES
bool "Kprobes (EXPERIMENTAL)"
depends on KALLSYMS && EXPERIMENTAL && MODULES
+ select FREEZER
help
Kprobes allows you to trap at almost any kernel address and
execute a callback function. register_kprobe() establishes
Index: linux-2.6.21-rc7-mm2/arch/avr32/Kconfig.debug
===================================================================
--- linux-2.6.21-rc7-mm2.orig/arch/avr32/Kconfig.debug 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/arch/avr32/Kconfig.debug 2007-04-27 21:54:19.000000000 +0200
@@ -12,6 +12,7 @@ menu "Instrumentation Support"
config KPROBES
bool "Kprobes"
depends on DEBUG_KERNEL
+ select FREEZER
help
Kprobes allows you to trap at almost any kernel address and
execute a callback function. register_kprobe() establishes
Index: linux-2.6.21-rc7-mm2/arch/frv/Kconfig
===================================================================
--- linux-2.6.21-rc7-mm2.orig/arch/frv/Kconfig 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/arch/frv/Kconfig 2007-04-27 21:54:34.000000000 +0200
@@ -57,6 +57,10 @@ config ARCH_USES_SLAB_PAGE_STRUCT
bool
default y

+config FREEZER
+ bool
+ default n
+
mainmenu "Fujitsu FR-V Kernel Configuration"

source "init/Kconfig"
Index: linux-2.6.21-rc7-mm2/arch/i386/Kconfig
===================================================================
--- linux-2.6.21-rc7-mm2.orig/arch/i386/Kconfig 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/arch/i386/Kconfig 2007-04-27 21:47:06.000000000 +0200
@@ -87,6 +87,10 @@ config DMI
bool
default y

+config FREEZER
+ bool
+ default n
+
source "init/Kconfig"

menu "Processor type and features"
@@ -1218,6 +1222,7 @@ source "arch/i386/oprofile/Kconfig"
config KPROBES
bool "Kprobes (EXPERIMENTAL)"
depends on KALLSYMS && EXPERIMENTAL && MODULES
+ select FREEZER
help
Kprobes allows you to trap at almost any kernel address and
execute a callback function. register_kprobe() establishes
Index: linux-2.6.21-rc7-mm2/arch/ia64/Kconfig
===================================================================
--- linux-2.6.21-rc7-mm2.orig/arch/ia64/Kconfig 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/arch/ia64/Kconfig 2007-04-27 21:47:49.000000000 +0200
@@ -90,6 +90,10 @@ config AUDIT_ARCH
bool
default y

+config FREEZER
+ bool
+ default n
+
choice
prompt "System type"
default IA64_GENERIC
@@ -582,6 +586,7 @@ source "arch/ia64/oprofile/Kconfig"
config KPROBES
bool "Kprobes (EXPERIMENTAL)"
depends on KALLSYMS && EXPERIMENTAL && MODULES
+ select FREEZER
help
Kprobes allows you to trap at almost any kernel address and
execute a callback function. register_kprobe() establishes
Index: linux-2.6.21-rc7-mm2/arch/powerpc/Kconfig
===================================================================
--- linux-2.6.21-rc7-mm2.orig/arch/powerpc/Kconfig 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/arch/powerpc/Kconfig 2007-04-27 21:50:26.000000000 +0200
@@ -123,6 +123,10 @@ config DEFAULT_UIMAGE
Used to allow a board to specify it wants a uImage built by default
default n

+config FREEZER
+ bool
+ default n
+
menu "Processor support"
choice
prompt "Processor Type"
@@ -865,6 +869,7 @@ source "arch/powerpc/oprofile/Kconfig"
config KPROBES
bool "Kprobes (EXPERIMENTAL)"
depends on !BOOKE && !4xx && KALLSYMS && EXPERIMENTAL && MODULES
+ select FREEZER
help
Kprobes allows you to trap at almost any kernel address and
execute a callback function. register_kprobe() establishes
Index: linux-2.6.21-rc7-mm2/arch/ppc/Kconfig
===================================================================
--- linux-2.6.21-rc7-mm2.orig/arch/ppc/Kconfig 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/arch/ppc/Kconfig 2007-04-27 21:55:17.000000000 +0200
@@ -65,6 +65,10 @@ config GENERIC_BUG
default y
depends on BUG

+config FREEZER
+ bool
+ default n
+
source "init/Kconfig"

menu "Processor"
Index: linux-2.6.21-rc7-mm2/arch/s390/Kconfig
===================================================================
--- linux-2.6.21-rc7-mm2.orig/arch/s390/Kconfig 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/arch/s390/Kconfig 2007-04-27 21:51:22.000000000 +0200
@@ -52,6 +52,10 @@ config NO_IOMEM
config NO_DMA
def_bool y

+config FREEZER
+ bool
+ default n
+
mainmenu "Linux Kernel Configuration"

config S390
@@ -557,6 +561,7 @@ source "arch/s390/oprofile/Kconfig"
config KPROBES
bool "Kprobes (EXPERIMENTAL)"
depends on EXPERIMENTAL && MODULES
+ select FREEZER
help
Kprobes allows you to trap at almost any kernel address and
execute a callback function. register_kprobe() establishes
Index: linux-2.6.21-rc7-mm2/arch/sh/Kconfig
===================================================================
--- linux-2.6.21-rc7-mm2.orig/arch/sh/Kconfig 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/arch/sh/Kconfig 2007-04-27 21:55:36.000000000 +0200
@@ -74,6 +74,10 @@ config ARCH_HAS_ILOG2_U64
bool
default n

+config FREEZER
+ bool
+ default n
+
source "init/Kconfig"

menu "System type"
Index: linux-2.6.21-rc7-mm2/arch/sparc64/Kconfig
===================================================================
--- linux-2.6.21-rc7-mm2.orig/arch/sparc64/Kconfig 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/arch/sparc64/Kconfig 2007-04-27 21:52:31.000000000 +0200
@@ -58,6 +58,10 @@ config AUDIT_ARCH
bool
default y

+config FREEZER
+ bool
+ default n
+
choice
prompt "Kernel page size"
default SPARC64_PAGE_SIZE_8KB
@@ -428,6 +432,7 @@ source "arch/sparc64/oprofile/Kconfig"
config KPROBES
bool "Kprobes (EXPERIMENTAL)"
depends on KALLSYMS && EXPERIMENTAL && MODULES
+ select FREEZER
help
Kprobes allows you to trap at almost any kernel address and
execute a callback function. register_kprobe() establishes
Index: linux-2.6.21-rc7-mm2/kernel/Makefile
===================================================================
--- linux-2.6.21-rc7-mm2.orig/kernel/Makefile 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/kernel/Makefile 2007-04-27 21:41:28.000000000 +0200
@@ -33,6 +33,7 @@ obj-$(CONFIG_MODULES) += module.o
obj-$(CONFIG_KALLSYMS) += kallsyms.o
obj-$(CONFIG_STACK_UNWIND) += unwind.o
obj-$(CONFIG_PM) += power/
+obj-$(CONFIG_FREEZER) += freezer.o
obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
obj-$(CONFIG_KEXEC) += kexec.o
obj-$(CONFIG_COMPAT) += compat.o
Index: linux-2.6.21-rc7-mm2/kernel/power/Makefile
===================================================================
--- linux-2.6.21-rc7-mm2.orig/kernel/power/Makefile 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/kernel/power/Makefile 2007-04-27 21:41:28.000000000 +0200
@@ -3,7 +3,7 @@ ifeq ($(CONFIG_PM_DEBUG),y)
EXTRA_CFLAGS += -DDEBUG
endif

-obj-y := main.o process.o console.o notify.o
+obj-y := main.o console.o notify.o
obj-$(CONFIG_PM_LEGACY) += pm.o
obj-$(CONFIG_SOFTWARE_SUSPEND) += swsusp.o disk.o snapshot.o swap.o user.o

Index: linux-2.6.21-rc7-mm2/kernel/kprobes.c
===================================================================
--- linux-2.6.21-rc7-mm2.orig/kernel/kprobes.c 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/kernel/kprobes.c 2007-04-27 21:41:28.000000000 +0200
@@ -108,7 +108,7 @@ static int collect_garbage_slots(void);
static int __kprobes check_safety(void)
{
int ret = 0;
-#if defined(CONFIG_PREEMPT) && defined(CONFIG_PM)
+#ifdef CONFIG_PREEMPT
ret = freeze_processes();
if (ret == 0) {
struct task_struct *p, *q;
Index: linux-2.6.21-rc7-mm2/include/linux/freezer.h
===================================================================
--- linux-2.6.21-rc7-mm2.orig/include/linux/freezer.h 2007-04-27 21:41:27.000000000 +0200
+++ linux-2.6.21-rc7-mm2/include/linux/freezer.h 2007-04-27 21:41:28.000000000 +0200
@@ -2,7 +2,7 @@

#include <linux/sched.h>

-#ifdef CONFIG_PM
+#ifdef CONFIG_FREEZER
/*
* Check if a process has been frozen
*/
Index: linux-2.6.21-rc7-mm2/arch/arm/Kconfig
===================================================================
--- linux-2.6.21-rc7-mm2.orig/arch/arm/Kconfig 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/arch/arm/Kconfig 2007-04-27 21:53:57.000000000 +0200
@@ -41,6 +41,10 @@ config NO_IOPORT
bool
default n

+config FREEZER
+ bool
+ default n
+
config EISA
bool
---help---
Index: linux-2.6.21-rc7-mm2/arch/blackfin/Kconfig
===================================================================
--- linux-2.6.21-rc7-mm2.orig/arch/blackfin/Kconfig 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/arch/blackfin/Kconfig 2007-04-27 21:54:27.000000000 +0200
@@ -69,6 +69,10 @@ config IRQCHIP_DEMUX_GPIO
bool
default y

+config FREEZER
+ bool
+ default n
+
source "init/Kconfig"
source "kernel/Kconfig.preempt"

Index: linux-2.6.21-rc7-mm2/arch/mips/Kconfig
===================================================================
--- linux-2.6.21-rc7-mm2.orig/arch/mips/Kconfig 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/arch/mips/Kconfig 2007-04-27 21:54:56.000000000 +0200
@@ -877,6 +877,10 @@ config GENERIC_HARDIRQS_NO__DO_IRQ
bool
default n

+config FREEZER
+ bool
+ default n
+
#
# Select some configuration options automatically based on user selections.
#
Index: linux-2.6.21-rc7-mm2/kernel/freezer.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6.21-rc7-mm2/kernel/freezer.c 2007-04-27 21:41:28.000000000 +0200
@@ -0,0 +1,236 @@
+/*
+ * linux/kernel/freezer.c
+ *
+ * Generic mechanism for freezing and thawing tasks, originally from swsusp.
+ *
+ * Distributed under the GPLv2
+ */
+
+
+#undef DEBUG
+
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/syscalls.h>
+#include <linux/freezer.h>
+
+/*
+ * Timeout for stopping processes
+ */
+#define TIMEOUT (20 * HZ)
+
+#define FREEZER_KERNEL_THREADS 0
+#define FREEZER_USER_SPACE 1
+
+static inline int freezeable(struct task_struct * p)
+{
+ if ((p == current) ||
+ (p->flags & PF_NOFREEZE) ||
+ (p->exit_state != 0))
+ return 0;
+ return 1;
+}
+
+/*
+ * freezing is complete, mark current process as frozen
+ */
+static inline void frozen_process(void)
+{
+ if (!unlikely(current->flags & PF_NOFREEZE)) {
+ current->flags |= PF_FROZEN;
+ wmb();
+ }
+ clear_tsk_thread_flag(current, TIF_FREEZE);
+}
+
+/* Refrigerator is place where frozen processes are stored :-). */
+void refrigerator(void)
+{
+ /* Hmm, should we be allowed to suspend when there are realtime
+ processes around? */
+ long save;
+
+ task_lock(current);
+ if (freezing(current)) {
+ frozen_process();
+ task_unlock(current);
+ } else {
+ task_unlock(current);
+ return;
+ }
+ save = current->state;
+ pr_debug("%s entered refrigerator\n", current->comm);
+
+ spin_lock_irq(&current->sighand->siglock);
+ recalc_sigpending(); /* We sent fake signal, clean it up */
+ spin_unlock_irq(&current->sighand->siglock);
+
+ for (;;) {
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ if (!frozen(current))
+ break;
+ schedule();
+ }
+ pr_debug("%s left refrigerator\n", current->comm);
+ current->state = save;
+}
+
+static inline void freeze_process(struct task_struct *p)
+{
+ unsigned long flags;
+
+ if (!freezing(p)) {
+ rmb();
+ if (!frozen(p)) {
+ if (p->state == TASK_STOPPED)
+ force_sig_specific(SIGSTOP, p);
+
+ freeze(p);
+ spin_lock_irqsave(&p->sighand->siglock, flags);
+ signal_wake_up(p, p->state == TASK_STOPPED);
+ spin_unlock_irqrestore(&p->sighand->siglock, flags);
+ }
+ }
+}
+
+static void cancel_freezing(struct task_struct *p)
+{
+ unsigned long flags;
+
+ if (freezing(p)) {
+ pr_debug(" clean up: %s\n", p->comm);
+ do_not_freeze(p);
+ spin_lock_irqsave(&p->sighand->siglock, flags);
+ recalc_sigpending_tsk(p);
+ spin_unlock_irqrestore(&p->sighand->siglock, flags);
+ }
+}
+
+static inline int is_user_space(struct task_struct *p)
+{
+ int ret;
+
+ task_lock(p);
+ ret = p->mm && !(p->flags & PF_BORROWED_MM);
+ task_unlock(p);
+ return ret;
+}
+
+static unsigned int try_to_freeze_tasks(int freeze_user_space)
+{
+ struct task_struct *g, *p;
+ unsigned long end_time;
+ unsigned int todo;
+
+ end_time = jiffies + TIMEOUT;
+ do {
+ todo = 0;
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ if (!freezeable(p))
+ continue;
+
+ if (frozen(p))
+ continue;
+
+ if (p->state == TASK_TRACED && frozen(p->parent)) {
+ cancel_freezing(p);
+ continue;
+ }
+ if (freeze_user_space && !is_user_space(p))
+ continue;
+
+ freeze_process(p);
+ if (!freezer_should_skip(p))
+ todo++;
+ } while_each_thread(g, p);
+ read_unlock(&tasklist_lock);
+ yield(); /* Yield is okay here */
+ if (todo && time_after(jiffies, end_time))
+ break;
+ } while (todo);
+
+ if (todo) {
+ /* This does not unfreeze processes that are already frozen
+ * (we have slightly ugly calling convention in that respect,
+ * and caller must call thaw_processes() if something fails),
+ * but it cleans up leftover PF_FREEZE requests.
+ */
+ printk("\n");
+ printk(KERN_ERR "Stopping %s timed out after %d seconds "
+ "(%d tasks refusing to freeze):\n",
+ freeze_user_space ? "user space processes" :
+ "kernel threads",
+ TIMEOUT / HZ, todo);
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ if (freeze_user_space && !is_user_space(p))
+ continue;
+
+ task_lock(p);
+ if (freezeable(p) && !frozen(p) &&
+ !freezer_should_skip(p))
+ printk(KERN_ERR " %s\n", p->comm);
+
+ cancel_freezing(p);
+ task_unlock(p);
+ } while_each_thread(g, p);
+ read_unlock(&tasklist_lock);
+ }
+
+ return todo;
+}
+
+/**
+ * freeze_processes - tell processes to enter the refrigerator
+ *
+ * Returns 0 on success, or the number of processes that didn't freeze,
+ * although they were told to.
+ */
+int freeze_processes(void)
+{
+ unsigned int nr_unfrozen;
+
+ printk("Stopping tasks ... ");
+ nr_unfrozen = try_to_freeze_tasks(FREEZER_USER_SPACE);
+ if (nr_unfrozen)
+ return nr_unfrozen;
+
+ sys_sync();
+ nr_unfrozen = try_to_freeze_tasks(FREEZER_KERNEL_THREADS);
+ if (nr_unfrozen)
+ return nr_unfrozen;
+
+ printk("done.\n");
+ BUG_ON(in_atomic());
+ return 0;
+}
+
+static void thaw_tasks(int thaw_user_space)
+{
+ struct task_struct *g, *p;
+
+ read_lock(&tasklist_lock);
+ do_each_thread(g, p) {
+ if (!freezeable(p))
+ continue;
+
+ if (is_user_space(p) == !thaw_user_space)
+ continue;
+
+ thaw_process(p);
+ } while_each_thread(g, p);
+ read_unlock(&tasklist_lock);
+}
+
+void thaw_processes(void)
+{
+ printk("Restarting tasks ... ");
+ thaw_tasks(FREEZER_KERNEL_THREADS);
+ thaw_tasks(FREEZER_USER_SPACE);
+ schedule();
+ printk("done.\n");
+}
+
+EXPORT_SYMBOL(refrigerator);
Index: linux-2.6.21-rc7-mm2/kernel/power/process.c
===================================================================
--- linux-2.6.21-rc7-mm2.orig/kernel/power/process.c 2007-04-27 21:41:27.000000000 +0200
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,236 +0,0 @@
-/*
- * drivers/power/process.c - Functions for starting/stopping processes on
- * suspend transitions.
- *
- * Originally from swsusp.
- */
-
-
-#undef DEBUG
-
-#include <linux/sched.h>
-#include <linux/interrupt.h>
-#include <linux/suspend.h>
-#include <linux/module.h>
-#include <linux/syscalls.h>
-#include <linux/freezer.h>
-
-/*
- * Timeout for stopping processes
- */
-#define TIMEOUT (20 * HZ)
-
-#define FREEZER_KERNEL_THREADS 0
-#define FREEZER_USER_SPACE 1
-
-static inline int freezeable(struct task_struct * p)
-{
- if ((p == current) ||
- (p->flags & PF_NOFREEZE) ||
- (p->exit_state != 0))
- return 0;
- return 1;
-}
-
-/*
- * freezing is complete, mark current process as frozen
- */
-static inline void frozen_process(void)
-{
- if (!unlikely(current->flags & PF_NOFREEZE)) {
- current->flags |= PF_FROZEN;
- wmb();
- }
- clear_tsk_thread_flag(current, TIF_FREEZE);
-}
-
-/* Refrigerator is place where frozen processes are stored :-). */
-void refrigerator(void)
-{
- /* Hmm, should we be allowed to suspend when there are realtime
- processes around? */
- long save;
-
- task_lock(current);
- if (freezing(current)) {
- frozen_process();
- task_unlock(current);
- } else {
- task_unlock(current);
- return;
- }
- save = current->state;
- pr_debug("%s entered refrigerator\n", current->comm);
-
- spin_lock_irq(&current->sighand->siglock);
- recalc_sigpending(); /* We sent fake signal, clean it up */
- spin_unlock_irq(&current->sighand->siglock);
-
- for (;;) {
- set_current_state(TASK_UNINTERRUPTIBLE);
- if (!frozen(current))
- break;
- schedule();
- }
- pr_debug("%s left refrigerator\n", current->comm);
- current->state = save;
-}
-
-static inline void freeze_process(struct task_struct *p)
-{
- unsigned long flags;
-
- if (!freezing(p)) {
- rmb();
- if (!frozen(p)) {
- if (p->state == TASK_STOPPED)
- force_sig_specific(SIGSTOP, p);
-
- freeze(p);
- spin_lock_irqsave(&p->sighand->siglock, flags);
- signal_wake_up(p, p->state == TASK_STOPPED);
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
- }
- }
-}
-
-static void cancel_freezing(struct task_struct *p)
-{
- unsigned long flags;
-
- if (freezing(p)) {
- pr_debug(" clean up: %s\n", p->comm);
- do_not_freeze(p);
- spin_lock_irqsave(&p->sighand->siglock, flags);
- recalc_sigpending_tsk(p);
- spin_unlock_irqrestore(&p->sighand->siglock, flags);
- }
-}
-
-static inline int is_user_space(struct task_struct *p)
-{
- int ret;
-
- task_lock(p);
- ret = p->mm && !(p->flags & PF_BORROWED_MM);
- task_unlock(p);
- return ret;
-}
-
-static unsigned int try_to_freeze_tasks(int freeze_user_space)
-{
- struct task_struct *g, *p;
- unsigned long end_time;
- unsigned int todo;
-
- end_time = jiffies + TIMEOUT;
- do {
- todo = 0;
- read_lock(&tasklist_lock);
- do_each_thread(g, p) {
- if (!freezeable(p))
- continue;
-
- if (frozen(p))
- continue;
-
- if (p->state == TASK_TRACED && frozen(p->parent)) {
- cancel_freezing(p);
- continue;
- }
- if (freeze_user_space && !is_user_space(p))
- continue;
-
- freeze_process(p);
- if (!freezer_should_skip(p))
- todo++;
- } while_each_thread(g, p);
- read_unlock(&tasklist_lock);
- yield(); /* Yield is okay here */
- if (todo && time_after(jiffies, end_time))
- break;
- } while (todo);
-
- if (todo) {
- /* This does not unfreeze processes that are already frozen
- * (we have slightly ugly calling convention in that respect,
- * and caller must call thaw_processes() if something fails),
- * but it cleans up leftover PF_FREEZE requests.
- */
- printk("\n");
- printk(KERN_ERR "Stopping %s timed out after %d seconds "
- "(%d tasks refusing to freeze):\n",
- freeze_user_space ? "user space processes" :
- "kernel threads",
- TIMEOUT / HZ, todo);
- read_lock(&tasklist_lock);
- do_each_thread(g, p) {
- if (freeze_user_space && !is_user_space(p))
- continue;
-
- task_lock(p);
- if (freezeable(p) && !frozen(p) &&
- !freezer_should_skip(p))
- printk(KERN_ERR " %s\n", p->comm);
-
- cancel_freezing(p);
- task_unlock(p);
- } while_each_thread(g, p);
- read_unlock(&tasklist_lock);
- }
-
- return todo;
-}
-
-/**
- * freeze_processes - tell processes to enter the refrigerator
- *
- * Returns 0 on success, or the number of processes that didn't freeze,
- * although they were told to.
- */
-int freeze_processes(void)
-{
- unsigned int nr_unfrozen;
-
- printk("Stopping tasks ... ");
- nr_unfrozen = try_to_freeze_tasks(FREEZER_USER_SPACE);
- if (nr_unfrozen)
- return nr_unfrozen;
-
- sys_sync();
- nr_unfrozen = try_to_freeze_tasks(FREEZER_KERNEL_THREADS);
- if (nr_unfrozen)
- return nr_unfrozen;
-
- printk("done.\n");
- BUG_ON(in_atomic());
- return 0;
-}
-
-static void thaw_tasks(int thaw_user_space)
-{
- struct task_struct *g, *p;
-
- read_lock(&tasklist_lock);
- do_each_thread(g, p) {
- if (!freezeable(p))
- continue;
-
- if (is_user_space(p) == !thaw_user_space)
- continue;
-
- thaw_process(p);
- } while_each_thread(g, p);
- read_unlock(&tasklist_lock);
-}
-
-void thaw_processes(void)
-{
- printk("Restarting tasks ... ");
- thaw_tasks(FREEZER_KERNEL_THREADS);
- thaw_tasks(FREEZER_USER_SPACE);
- schedule();
- printk("done.\n");
-}
-
-EXPORT_SYMBOL(refrigerator);
Index: linux-2.6.21-rc7-mm2/arch/avr32/Kconfig
===================================================================
--- linux-2.6.21-rc7-mm2.orig/arch/avr32/Kconfig 2007-04-27 01:00:50.000000000 +0200
+++ linux-2.6.21-rc7-mm2/arch/avr32/Kconfig 2007-04-27 21:44:56.000000000 +0200
@@ -73,6 +73,10 @@ config GENERIC_BUG
default y
depends on BUG

+config FREEZER
+ bool
+ default n
+
source "init/Kconfig"

menu "System Type and features"
Index: linux-2.6.21-rc7-mm2/kernel/power/Kconfig
===================================================================
--- linux-2.6.21-rc7-mm2.orig/kernel/power/Kconfig 2007-04-27 21:41:05.000000000 +0200
+++ linux-2.6.21-rc7-mm2/kernel/power/Kconfig 2007-04-27 21:42:52.000000000 +0200
@@ -1,6 +1,7 @@
config PM
bool "Power Management support"
depends on !IA64_HP_SIM
+ select FREEZER
---help---
"Power Management" means that parts of your computer are shut
off or put into a power conserving "sleep" mode if they are not
-
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