This patch provides an interface to extend the use of the process
freezer beyond Suspend.
The tasks can selectively mark themselves to be exempted from specific
freeze events like SUSPEND /KPROBES/CPU_HOTPLUG.
This patch however, *does not* sort non freezable threads into
different categories based on the freeze events. Thus all
tasks which were previously marked PF_NOFREEZE are now
exempted from freezer using
freezer_exempt(FE_ALL);
which means exempt from all kinds of freezes.
Signed-off-by: Gautham R Shenoy <[EMAIL PROTECTED]>
Cc: Pavel Machek <[EMAIL PROTECTED]>
Cc: Rafael J. Wysocki <[EMAIL PROTECTED]>
Cc: Masami Hiramatsu <[EMAIL PROTECTED]>
--
arch/i386/kernel/apm.c | 2 -
drivers/block/loop.c | 2 -
drivers/char/apm-emulation.c | 6 ++--
drivers/ieee1394/ieee1394_core.c | 2 -
drivers/md/md.c | 2 -
drivers/mmc/card/queue.c | 3 +-
drivers/mtd/mtd_blkdevs.c | 3 +-
drivers/scsi/libsas/sas_scsi_host.c | 2 -
drivers/scsi/scsi_error.c | 2 -
drivers/usb/storage/usb.c | 2 -
include/linux/freezer.h | 52 ++++++++++++++++++++++++++++++++----
include/linux/sched.h | 15 +++++++++-
init/do_mounts_initrd.c | 2 -
kernel/fork.c | 2 -
kernel/kprobes.c | 4 +-
kernel/power/disk.c | 4 +-
kernel/power/main.c | 6 ++--
kernel/power/process.c | 29 +++++++++++---------
kernel/power/user.c | 8 ++---
kernel/rcutorture.c | 4 +-
kernel/sched.c | 2 -
kernel/softirq.c | 2 -
kernel/softlockup.c | 2 -
kernel/workqueue.c | 2 -
24 files changed, 110 insertions(+), 50 deletions(-)
Index: linux-2.6.21-rc5/include/linux/sched.h
===================================================================
--- linux-2.6.21-rc5.orig/include/linux/sched.h
+++ linux-2.6.21-rc5/include/linux/sched.h
@@ -1186,8 +1186,21 @@ static inline void put_task_struct(struc
#define PF_MEMALLOC 0x00000800 /* Allocating memory */
#define PF_FLUSHER 0x00001000 /* responsible for disk writeback */
#define PF_USED_MATH 0x00002000 /* if unset the fpu must be initialized
before use */
-#define PF_NOFREEZE 0x00008000 /* this thread should not be frozen */
+
+/* Per process freezer specific flags */
+#define PF_FE_SUSPEND 0x00008000 /* This thread should not be frozen
+ * for suspend
+ */
+
+#define PF_FE_KPROBES 0x00000010 /* This thread should not be frozen
+ * for Kprobes
+ */
+
#define PF_FROZEN 0x00010000 /* frozen for system suspend */
+
+#define PF_FE_ALL (PF_FE_SUSPEND | PF_FE_KPROBES)
+ /* Exempt from all kinds freeze chills*/
+
#define PF_FSTRANS 0x00020000 /* inside a filesystem transaction */
#define PF_KSWAPD 0x00040000 /* I am kswapd */
#define PF_SWAPOFF 0x00080000 /* I am in swapoff */
Index: linux-2.6.21-rc5/include/linux/freezer.h
===================================================================
--- linux-2.6.21-rc5.orig/include/linux/freezer.h
+++ linux-2.6.21-rc5/include/linux/freezer.h
@@ -2,7 +2,49 @@
#include <linux/sched.h>
-#ifdef CONFIG_PM
+#if defined(CONFIG_PM) || defined(CONFIG_HOTPLUG_CPU) || \
+ defined(CONFIG_KPROBES)
+
+/* These are the events which make use of the process freezer */
+#define FE_NONE 0
+#define FE_ALL PF_FE_ALL
+#define FE_SUSPEND PF_FE_SUSPEND
+#define FE_KPROBES PF_FE_KPROBES
+
+/*
+ * Exempt the current process from being frozen for a certain event
+ */
+static inline void freezer_exempt(unsigned long exempt_freeze_event)
+{
+ if (exempt_freeze_event == FE_NONE)
+ current->flags &= ~PF_FE_ALL;
+ else
+ current->flags |= exempt_freeze_event;
+}
+
+/*
+ * Consider the current process to be frozen for a certain event
+ */
+static inline void freezer_consider(unsigned long freeze_event)
+{
+ current->flags &= ~freeze_event;
+}
+
+/*
+ * Check if the process is exempted from freeze for the particular event.
+ */
+static inline int freezer_is_exempted(struct task_struct *p,
+ unsigned long freeze_event)
+{
+ return p->flags & freeze_event;
+}
+
+/* Returns the mask of the events for which this process is freezeable */
+static inline unsigned long freezeable_event_mask(struct task_struct *p)
+{
+ return ~p->flags & PF_FE_ALL;
+}
+
/*
* Check if a process has been frozen
*/
@@ -63,8 +105,8 @@ static inline void frozen_process(struct
}
extern void refrigerator(void);
-extern int freeze_processes(void);
-extern void thaw_processes(void);
+extern int freeze_processes(unsigned long freeze_event);
+extern void thaw_processes(unsigned long freeze_event);
static inline int try_to_freeze(void)
{
@@ -127,8 +169,8 @@ static inline int thaw_process(struct ta
static inline void frozen_process(struct task_struct *p) { BUG(); }
static inline void refrigerator(void) {}
-static inline int freeze_processes(void) { BUG(); return 0; }
-static inline void thaw_processes(void) {}
+static inline int freeze_processes(int a) { BUG(); return 1; }
+static inline void thaw_processes(int a) {}
static inline int try_to_freeze(void) { return 0; }
Index: linux-2.6.21-rc5/kernel/power/process.c
===================================================================
--- linux-2.6.21-rc5.orig/kernel/power/process.c
+++ linux-2.6.21-rc5/kernel/power/process.c
@@ -24,10 +24,10 @@
#define FREEZER_KERNEL_THREADS 0
#define FREEZER_USER_SPACE 1
-static inline int freezeable(struct task_struct * p)
+static inline int freezeable(struct task_struct * p, unsigned long
freeze_event)
{
if ((p == current) ||
- (p->flags & PF_NOFREEZE) ||
+ (freezer_is_exempted(p, freeze_event)) ||
(p->exit_state != 0))
return 0;
return 1;
@@ -106,7 +106,8 @@ static inline int is_user_space(struct t
return ret;
}
-static unsigned int try_to_freeze_tasks(int freeze_user_space)
+static unsigned int try_to_freeze_tasks(int freeze_user_space,
+ unsigned long freeze_event)
{
struct task_struct *g, *p;
unsigned long end_time;
@@ -117,7 +118,7 @@ static unsigned int try_to_freeze_tasks(
todo = 0;
read_lock(&tasklist_lock);
do_each_thread(g, p) {
- if (!freezeable(p))
+ if (!freezeable(p, freeze_event))
continue;
if (frozen(p))
@@ -158,7 +159,7 @@ static unsigned int try_to_freeze_tasks(
continue;
task_lock(p);
- if (freezeable(p) && !frozen(p) &&
+ if (freezeable(p, freeze_event) && !frozen(p) &&
!freezer_should_skip(p))
printk(KERN_ERR " %s\n", p->comm);
@@ -173,21 +174,23 @@ static unsigned int try_to_freeze_tasks(
/**
* freeze_processes - tell processes to enter the refrigerator
+ * @freeze_event: The system event for which processes are being
+ * frozen.
*
* Returns 0 on success, or the number of processes that didn't freeze,
* although they were told to.
*/
-int freeze_processes(void)
+int freeze_processes(unsigned long freeze_event)
{
unsigned int nr_unfrozen;
printk("Stopping tasks ... ");
- nr_unfrozen = try_to_freeze_tasks(FREEZER_USER_SPACE);
+ nr_unfrozen = try_to_freeze_tasks(FREEZER_USER_SPACE, freeze_event);
if (nr_unfrozen)
return nr_unfrozen;
sys_sync();
- nr_unfrozen = try_to_freeze_tasks(FREEZER_KERNEL_THREADS);
+ nr_unfrozen = try_to_freeze_tasks(FREEZER_KERNEL_THREADS, freeze_event);
if (nr_unfrozen)
return nr_unfrozen;
@@ -196,13 +199,13 @@ int freeze_processes(void)
return 0;
}
-static void thaw_tasks(int thaw_user_space)
+static void thaw_tasks(int thaw_user_space, unsigned long freeze_event)
{
struct task_struct *g, *p;
read_lock(&tasklist_lock);
do_each_thread(g, p) {
- if (!freezeable(p))
+ if (!freezeable(p, freeze_event))
continue;
if (is_user_space(p) == !thaw_user_space)
@@ -213,11 +216,11 @@ static void thaw_tasks(int thaw_user_spa
read_unlock(&tasklist_lock);
}
-void thaw_processes(void)
+void thaw_processes(unsigned long freeze_event)
{
printk("Restarting tasks ... ");
- thaw_tasks(FREEZER_KERNEL_THREADS);
- thaw_tasks(FREEZER_USER_SPACE);
+ thaw_tasks(FREEZER_KERNEL_THREADS, freeze_event);
+ thaw_tasks(FREEZER_USER_SPACE, freeze_event);
schedule();
printk("done.\n");
}
Index: linux-2.6.21-rc5/kernel/sched.c
===================================================================
--- linux-2.6.21-rc5.orig/kernel/sched.c
+++ linux-2.6.21-rc5/kernel/sched.c
@@ -5057,6 +5057,7 @@ static int migration_thread(void *data)
BUG_ON(rq->migration_thread != current);
set_current_state(TASK_INTERRUPTIBLE);
+ freezer_exempt(FE_ALL);
while (!kthread_should_stop()) {
struct migration_req *req;
struct list_head *head;
@@ -5407,7 +5408,6 @@ migration_call(struct notifier_block *nf
p = kthread_create(migration_thread, hcpu, "migration/%d",cpu);
if (IS_ERR(p))
return NOTIFY_BAD;
- p->flags |= PF_NOFREEZE;
kthread_bind(p, cpu);
/* Must be high prio: stop_machine expects to yield to it. */
rq = task_rq_lock(p, &flags);
Index: linux-2.6.21-rc5/kernel/softlockup.c
===================================================================
--- linux-2.6.21-rc5.orig/kernel/softlockup.c
+++ linux-2.6.21-rc5/kernel/softlockup.c
@@ -96,7 +96,7 @@ static int watchdog(void * __bind_cpu)
struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
sched_setscheduler(current, SCHED_FIFO, ¶m);
- current->flags |= PF_NOFREEZE;
+ freezer_exempt(FE_ALL);
/*
* Run briefly once per second to reset the softlockup timestamp.
Index: linux-2.6.21-rc5/kernel/workqueue.c
===================================================================
--- linux-2.6.21-rc5.orig/kernel/workqueue.c
+++ linux-2.6.21-rc5/kernel/workqueue.c
@@ -292,7 +292,7 @@ static int worker_thread(void *__cwq)
struct k_sigaction sa;
if (!cwq->wq->freezeable)
- current->flags |= PF_NOFREEZE;
+ freezer_exempt(FE_ALL);
/*
* We inherited MPOL_INTERLEAVE from the booting kernel.
Index: linux-2.6.21-rc5/kernel/rcutorture.c
===================================================================
--- linux-2.6.21-rc5.orig/kernel/rcutorture.c
+++ linux-2.6.21-rc5/kernel/rcutorture.c
@@ -559,7 +559,7 @@ rcu_torture_fakewriter(void *arg)
VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started");
set_user_nice(current, 19);
- current->flags |= PF_NOFREEZE;
+ freezer_exempt(FE_ALL);
do {
schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10);
@@ -590,7 +590,7 @@ rcu_torture_reader(void *arg)
VERBOSE_PRINTK_STRING("rcu_torture_reader task started");
set_user_nice(current, 19);
- current->flags |= PF_NOFREEZE;
+ freezer_exempt(FE_ALL);
do {
idx = cur_ops->readlock();
Index: linux-2.6.21-rc5/arch/i386/kernel/apm.c
===================================================================
--- linux-2.6.21-rc5.orig/arch/i386/kernel/apm.c
+++ linux-2.6.21-rc5/arch/i386/kernel/apm.c
@@ -1395,6 +1395,7 @@ static void apm_mainloop(void)
add_wait_queue(&apm_waitqueue, &wait);
set_current_state(TASK_INTERRUPTIBLE);
+ freezer_exempt(FE_ALL);
for (;;) {
try_to_freeze();
schedule_timeout(APM_CHECK_TIMEOUT);
@@ -2315,7 +2316,6 @@ static int __init apm_init(void)
remove_proc_entry("apm", NULL);
return err;
}
- kapmd_task->flags |= PF_NOFREEZE;
wake_up_process(kapmd_task);
if (num_online_cpus() > 1 && !smp ) {
Index: linux-2.6.21-rc5/drivers/char/apm-emulation.c
===================================================================
--- linux-2.6.21-rc5.orig/drivers/char/apm-emulation.c
+++ linux-2.6.21-rc5/drivers/char/apm-emulation.c
@@ -336,7 +336,7 @@ apm_ioctl(struct inode * inode, struct f
* threads.
*/
flags = current->flags;
- current->flags |= PF_NOFREEZE;
+ freezer_exempt(FE_ALL);
wait_event(apm_suspend_waitqueue,
as->suspend_state == SUSPEND_DONE);
@@ -372,7 +372,7 @@ apm_ioctl(struct inode * inode, struct f
* threads.
*/
flags = current->flags;
- current->flags |= PF_NOFREEZE;
+ freezer_exempt(FE_ALL);
wait_event_interruptible(apm_suspend_waitqueue,
as->suspend_state == SUSPEND_DONE);
@@ -536,6 +536,7 @@ static int apm_get_info(char *buf, char
static int kapmd(void *arg)
{
+ freezer_exempt(FE_ALL);
do {
apm_event_t event;
int ret;
@@ -601,7 +602,6 @@ static int __init apm_init(void)
kapmd_tsk = NULL;
return ret;
}
- kapmd_tsk->flags |= PF_NOFREEZE;
wake_up_process(kapmd_tsk);
#ifdef CONFIG_PROC_FS
Index: linux-2.6.21-rc5/drivers/block/loop.c
===================================================================
--- linux-2.6.21-rc5.orig/drivers/block/loop.c
+++ linux-2.6.21-rc5/drivers/block/loop.c
@@ -587,7 +587,7 @@ static int loop_thread(void *data)
* hence, it mustn't be stopped at all
* because it could be indirectly used during suspension
*/
- current->flags |= PF_NOFREEZE;
+ freezer_exempt(FE_ALL);
set_user_nice(current, -20);
Index: linux-2.6.21-rc5/drivers/ieee1394/ieee1394_core.c
===================================================================
--- linux-2.6.21-rc5.orig/drivers/ieee1394/ieee1394_core.c
+++ linux-2.6.21-rc5/drivers/ieee1394/ieee1394_core.c
@@ -1134,7 +1134,7 @@ static int hpsbpkt_thread(void *__hi)
struct list_head tmp;
int may_schedule;
- current->flags |= PF_NOFREEZE;
+ freezer_exempt(FE_ALL);
while (!kthread_should_stop()) {
Index: linux-2.6.21-rc5/drivers/md/md.c
===================================================================
--- linux-2.6.21-rc5.orig/drivers/md/md.c
+++ linux-2.6.21-rc5/drivers/md/md.c
@@ -4527,7 +4527,7 @@ static int md_thread(void * arg)
* many dirty RAID5 blocks.
*/
- current->flags |= PF_NOFREEZE;
+ freezer_exempt(FE_ALL);
allow_signal(SIGKILL);
while (!kthread_should_stop()) {
Index: linux-2.6.21-rc5/drivers/mtd/mtd_blkdevs.c
===================================================================
--- linux-2.6.21-rc5.orig/drivers/mtd/mtd_blkdevs.c
+++ linux-2.6.21-rc5/drivers/mtd/mtd_blkdevs.c
@@ -82,7 +82,8 @@ static int mtd_blktrans_thread(void *arg
struct request_queue *rq = tr->blkcore_priv->rq;
/* we might get involved when memory gets low, so use PF_MEMALLOC */
- current->flags |= PF_MEMALLOC | PF_NOFREEZE;
+ current->flags |= PF_MEMALLOC;
+ freezer_exempt(FE_ALL);
daemonize("%sd", tr->name);
Index: linux-2.6.21-rc5/drivers/scsi/libsas/sas_scsi_host.c
===================================================================
--- linux-2.6.21-rc5.orig/drivers/scsi/libsas/sas_scsi_host.c
+++ linux-2.6.21-rc5/drivers/scsi/libsas/sas_scsi_host.c
@@ -871,7 +871,7 @@ static int sas_queue_thread(void *_sas_h
struct scsi_core *core = &sas_ha->core;
daemonize("sas_queue_%d", core->shost->host_no);
- current->flags |= PF_NOFREEZE;
+ freezer_exempt(FE_ALL);
complete(&queue_th_comp);
Index: linux-2.6.21-rc5/drivers/scsi/scsi_error.c
===================================================================
--- linux-2.6.21-rc5.orig/drivers/scsi/scsi_error.c
+++ linux-2.6.21-rc5/drivers/scsi/scsi_error.c
@@ -1536,7 +1536,7 @@ int scsi_error_handler(void *data)
{
struct Scsi_Host *shost = data;
- current->flags |= PF_NOFREEZE;
+ freezer_exempt(FE_ALL);
/*
* We use TASK_INTERRUPTIBLE so that the thread is not
Index: linux-2.6.21-rc5/drivers/usb/storage/usb.c
===================================================================
--- linux-2.6.21-rc5.orig/drivers/usb/storage/usb.c
+++ linux-2.6.21-rc5/drivers/usb/storage/usb.c
@@ -301,7 +301,7 @@ static int usb_stor_control_thread(void
struct us_data *us = (struct us_data *)__us;
struct Scsi_Host *host = us_to_host(us);
- current->flags |= PF_NOFREEZE;
+ freezer_exempt(FE_ALL);
for(;;) {
try_to_freeze();
Index: linux-2.6.21-rc5/init/do_mounts_initrd.c
===================================================================
--- linux-2.6.21-rc5.orig/init/do_mounts_initrd.c
+++ linux-2.6.21-rc5/init/do_mounts_initrd.c
@@ -55,7 +55,7 @@ static void __init handle_initrd(void)
sys_mount(".", "/", NULL, MS_MOVE, NULL);
sys_chroot(".");
- current->flags |= PF_NOFREEZE;
+ freezer_exempt(FE_ALL);
pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
if (pid > 0) {
while (pid != sys_wait4(-1, NULL, 0, NULL))
Index: linux-2.6.21-rc5/kernel/softirq.c
===================================================================
--- linux-2.6.21-rc5.orig/kernel/softirq.c
+++ linux-2.6.21-rc5/kernel/softirq.c
@@ -490,7 +490,7 @@ void __init softirq_init(void)
static int ksoftirqd(void * __bind_cpu)
{
set_user_nice(current, 19);
- current->flags |= PF_NOFREEZE;
+ freezer_exempt(FE_ALL);
set_current_state(TASK_INTERRUPTIBLE);
Index: linux-2.6.21-rc5/kernel/kprobes.c
===================================================================
--- linux-2.6.21-rc5.orig/kernel/kprobes.c
+++ linux-2.6.21-rc5/kernel/kprobes.c
@@ -104,7 +104,7 @@ static int __kprobes check_safety(void)
{
int ret = 0;
#if defined(CONFIG_PREEMPT) && defined(CONFIG_PM)
- ret = freeze_processes();
+ ret = freeze_processes(FE_KPROBES);
if (ret == 0) {
struct task_struct *p, *q;
do_each_thread(p, q) {
@@ -117,7 +117,7 @@ static int __kprobes check_safety(void)
} while_each_thread(p, q);
}
loop_end:
- thaw_processes();
+ thaw_processes(FE_KPROBES);
#else
synchronize_sched();
#endif
Index: linux-2.6.21-rc5/kernel/power/disk.c
===================================================================
--- linux-2.6.21-rc5.orig/kernel/power/disk.c
+++ linux-2.6.21-rc5/kernel/power/disk.c
@@ -104,7 +104,7 @@ static inline void platform_finish(void)
static void unprepare_processes(void)
{
- thaw_processes();
+ thaw_processes(FE_SUSPEND);
pm_restore_console();
}
@@ -113,7 +113,7 @@ static int prepare_processes(void)
int error = 0;
pm_prepare_console();
- if (freeze_processes()) {
+ if (freeze_processes(FE_SUSPEND)) {
error = -EBUSY;
unprepare_processes();
}
Index: linux-2.6.21-rc5/kernel/power/main.c
===================================================================
--- linux-2.6.21-rc5.orig/kernel/power/main.c
+++ linux-2.6.21-rc5/kernel/power/main.c
@@ -86,7 +86,7 @@ static int suspend_prepare(suspend_state
pm_prepare_console();
- if (freeze_processes()) {
+ if (freeze_processes(FE_SUSPEND)) {
error = -EAGAIN;
goto Thaw;
}
@@ -123,7 +123,7 @@ static int suspend_prepare(suspend_state
device_resume();
resume_console();
Thaw:
- thaw_processes();
+ thaw_processes(FE_SUSPEND);
pm_restore_console();
return error;
}
@@ -162,7 +162,7 @@ static void suspend_finish(suspend_state
pm_finish(state);
device_resume();
resume_console();
- thaw_processes();
+ thaw_processes(FE_SUSPEND);
pm_restore_console();
}
Index: linux-2.6.21-rc5/kernel/power/user.c
===================================================================
--- linux-2.6.21-rc5.orig/kernel/power/user.c
+++ linux-2.6.21-rc5/kernel/power/user.c
@@ -88,7 +88,7 @@ static int snapshot_release(struct inode
free_bitmap(data->bitmap);
if (data->frozen) {
mutex_lock(&pm_mutex);
- thaw_processes();
+ thaw_processes(FE_SUSPEND);
enable_nonboot_cpus();
mutex_unlock(&pm_mutex);
}
@@ -239,8 +239,8 @@ static int snapshot_ioctl(struct inode *
if (data->frozen)
break;
mutex_lock(&pm_mutex);
- if (freeze_processes()) {
- thaw_processes();
+ if (freeze_processes(FE_SUSPEND)) {
+ thaw_processes(FE_SUSPEND);
error = -EBUSY;
}
mutex_unlock(&pm_mutex);
@@ -252,7 +252,7 @@ static int snapshot_ioctl(struct inode *
if (!data->frozen)
break;
mutex_lock(&pm_mutex);
- thaw_processes();
+ thaw_processes(FE_SUSPEND);
mutex_unlock(&pm_mutex);
data->frozen = 0;
break;
Index: linux-2.6.21-rc5/drivers/mmc/card/queue.c
===================================================================
--- linux-2.6.21-rc5.orig/drivers/mmc/card/queue.c
+++ linux-2.6.21-rc5/drivers/mmc/card/queue.c
@@ -66,7 +66,8 @@ static int mmc_queue_thread(void *d)
* Set iothread to ensure that we aren't put to sleep by
* the process freezing. We handle suspension ourselves.
*/
- current->flags |= PF_MEMALLOC|PF_NOFREEZE;
+ current->flags |= PF_MEMALLOC;
+ freezer_exempt(FE_ALL);
down(&mq->thread_sem);
do {
Index: linux-2.6.21-rc5/kernel/fork.c
===================================================================
--- linux-2.6.21-rc5.orig/kernel/fork.c
+++ linux-2.6.21-rc5/kernel/fork.c
@@ -921,7 +921,7 @@ static inline void copy_flags(unsigned l
{
unsigned long new_flags = p->flags;
- new_flags &= ~(PF_SUPERPRIV | PF_NOFREEZE);
+ new_flags &= ~(PF_SUPERPRIV | PF_FE_ALL);
new_flags |= PF_FORKNOEXEC;
new_flags |= PF_STARTING;
p->flags = new_flags;
--
Gautham R Shenoy
Linux Technology Center
IBM India.
"Freedom comes with a price tag of responsibility, which is still a bargain,
because Freedom is priceless!"
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