[PATCH] Cleanup patch for process freezing
1. Establish a simple API for process freezing defined in linux/include/sched.h:
frozen(process) Check for frozen process
freezing(process) Check if a process is being frozen
freeze(process) Tell a process to freeze (go to refrigerator)
thaw_process(process) Restart process
frozen_process(process) Process is frozen now
2. Remove all references to PF_FREEZE and PF_FROZEN from all
kernel sources except sched.h
3. Fix numerous locations where try_to_freeze is manually done by a driver
4. Remove the argument that is no longer necessary from two function calls.
5. Some whitespace cleanup
6. Clear potential race in refrigerator (provides an open window of PF_FREEZE
cleared before setting PF_FROZEN, recalc_sigpending does not check
PF_FROZEN).
This patch does not address the problem of freeze_processes() violating the rule
that a task may only modify its own flags by setting PF_FREEZE. This is not clean
in an SMP environment. freeze(process) is therefore not SMP safe!
Signed-off-by: Christoph Lameter <christoph@lameter.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 7f3d78d..7b83834 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -1251,8 +1251,7 @@
VPRINTK("kcdrwd: wake up\n");
/* make swsusp happy with our thread */
- if (current->flags & PF_FREEZE)
- refrigerator(PF_FREEZE);
+ try_to_freeze();
list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
if (!pkt->sleep_time)
diff --git a/drivers/ieee1394/ieee1394_core.c b/drivers/ieee1394/ieee1394_core.c
index 2d9a9b7..629070b 100644
--- a/drivers/ieee1394/ieee1394_core.c
+++ b/drivers/ieee1394/ieee1394_core.c
@@ -1041,10 +1041,8 @@
while (1) {
if (down_interruptible(&khpsbpkt_sig)) {
- if (current->flags & PF_FREEZE) {
- refrigerator(0);
+ if (try_to_freeze())
continue;
- }
printk("khpsbpkt: received unexpected signal?!\n" );
break;
}
diff --git a/drivers/ieee1394/nodemgr.c b/drivers/ieee1394/nodemgr.c
index 32abb6d..9a46c3b 100644
--- a/drivers/ieee1394/nodemgr.c
+++ b/drivers/ieee1394/nodemgr.c
@@ -1510,7 +1510,7 @@
if (down_interruptible(&hi->reset_sem) ||
down_interruptible(&nodemgr_serialize)) {
- if (try_to_freeze(PF_FREEZE))
+ if (try_to_freeze())
continue;
printk("NodeMgr: received unexpected signal?!\n" );
break;
diff --git a/drivers/input/gameport/gameport.c b/drivers/input/gameport/gameport.c
index e152d0f..c77a82e 100644
--- a/drivers/input/gameport/gameport.c
+++ b/drivers/input/gameport/gameport.c
@@ -439,7 +439,7 @@
do {
gameport_handle_events();
wait_event_interruptible(gameport_wait, !list_empty(&gameport_event_list));
- try_to_freeze(PF_FREEZE);
+ try_to_freeze();
} while (!signal_pending(current));
printk(KERN_DEBUG "gameport: kgameportd exiting\n");
diff --git a/drivers/input/serio/serio.c b/drivers/input/serio/serio.c
index feab497..341824c 100644
--- a/drivers/input/serio/serio.c
+++ b/drivers/input/serio/serio.c
@@ -344,7 +344,7 @@
do {
serio_handle_events();
wait_event_interruptible(serio_wait, !list_empty(&serio_event_list));
- try_to_freeze(PF_FREEZE);
+ try_to_freeze();
} while (!signal_pending(current));
printk(KERN_DEBUG "serio: kseriod exiting\n");
diff --git a/drivers/macintosh/therm_adt746x.c b/drivers/macintosh/therm_adt746x.c
index 5ba190c..c9ca111 100644
--- a/drivers/macintosh/therm_adt746x.c
+++ b/drivers/macintosh/therm_adt746x.c
@@ -328,9 +328,7 @@
struct thermostat* th = arg;
while(!kthread_should_stop()) {
- if (current->flags & PF_FREEZE)
- refrigerator(PF_FREEZE);
-
+ try_to_freeze();
msleep_interruptible(2000);
#ifndef DEBUG
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 0c6b5b6..3802f7a 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2976,8 +2976,7 @@
wait_event_interruptible_timeout(thread->wqueue,
test_bit(THREAD_WAKEUP, &thread->flags),
thread->timeout);
- if (current->flags & PF_FREEZE)
- refrigerator(PF_FREEZE);
+ try_to_freeze();
clear_bit(THREAD_WAKEUP, &thread->flags);
diff --git a/drivers/media/dvb/dvb-core/dvb_frontend.c b/drivers/media/dvb/dvb-core/dvb_frontend.c
index d6b7a9d..f11daae 100644
--- a/drivers/media/dvb/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb/dvb-core/dvb_frontend.c
@@ -391,8 +391,7 @@
break;
}
- if (current->flags & PF_FREEZE)
- refrigerator(PF_FREEZE);
+ try_to_freeze();
if (down_interruptible(&fepriv->sem))
break;
diff --git a/drivers/media/video/msp3400.c b/drivers/media/video/msp3400.c
index 1b7d38e..b4ee9df 100644
--- a/drivers/media/video/msp3400.c
+++ b/drivers/media/video/msp3400.c
@@ -750,8 +750,7 @@
#endif
}
}
- if (current->flags & PF_FREEZE)
- refrigerator(PF_FREEZE);
+ try_to_freeze();
remove_wait_queue(&msp->wq, &wait);
return msp->restart;
}
diff --git a/drivers/media/video/video-buf-dvb.c b/drivers/media/video/video-buf-dvb.c
index 5f87007..15f5bb4 100644
--- a/drivers/media/video/video-buf-dvb.c
+++ b/drivers/media/video/video-buf-dvb.c
@@ -62,8 +62,7 @@
break;
if (kthread_should_stop())
break;
- if (current->flags & PF_FREEZE)
- refrigerator(PF_FREEZE);
+ try_to_freeze();
/* feed buffer data to demux */
if (buf->state == STATE_DONE)
diff --git a/drivers/net/8139too.c b/drivers/net/8139too.c
index 047202c..5a4a08a 100644
--- a/drivers/net/8139too.c
+++ b/drivers/net/8139too.c
@@ -1606,7 +1606,7 @@
do {
timeout = interruptible_sleep_on_timeout (&tp->thr_wait, timeout);
/* make swsusp happy with our thread */
- try_to_freeze(PF_FREEZE);
+ try_to_freeze();
} while (!signal_pending (current) && (timeout > 0));
if (signal_pending (current)) {
diff --git a/drivers/net/irda/sir_kthread.c b/drivers/net/irda/sir_kthread.c
index 18cea10..c650543 100644
--- a/drivers/net/irda/sir_kthread.c
+++ b/drivers/net/irda/sir_kthread.c
@@ -135,8 +135,7 @@
remove_wait_queue(&irda_rq_queue.kick, &wait);
/* make swsusp happy with our thread */
- if (current->flags & PF_FREEZE)
- refrigerator(PF_FREEZE);
+ try_to_freeze();
run_irda_queue();
}
diff --git a/drivers/net/irda/stir4200.c b/drivers/net/irda/stir4200.c
index 66f488c..15f2073 100644
--- a/drivers/net/irda/stir4200.c
+++ b/drivers/net/irda/stir4200.c
@@ -763,7 +763,7 @@
{
#ifdef CONFIG_PM
/* if suspending, then power off and wait */
- if (unlikely(current->flags & PF_FREEZE)) {
+ if (unlikely(freezing(current))) {
if (stir->receiving)
receive_stop(stir);
else
@@ -771,7 +771,7 @@
write_reg(stir, REG_CTRL1, CTRL1_TXPWD|CTRL1_RXPWD);
- refrigerator(PF_FREEZE);
+ refrigerator();
if (change_speed(stir, stir->speed))
break;
diff --git a/drivers/net/wireless/airo.c b/drivers/net/wireless/airo.c
index fb10a2d..d72e038 100644
--- a/drivers/net/wireless/airo.c
+++ b/drivers/net/wireless/airo.c
@@ -2918,7 +2918,7 @@
flush_signals(current);
/* make swsusp happy with our thread */
- try_to_freeze(PF_FREEZE);
+ try_to_freeze();
if (test_bit(JOB_DIE, &ai->flags))
break;
diff --git a/drivers/pcmcia/cs.c b/drivers/pcmcia/cs.c
index d136b3c..48e4f04 100644
--- a/drivers/pcmcia/cs.c
+++ b/drivers/pcmcia/cs.c
@@ -718,7 +718,7 @@
}
schedule();
- try_to_freeze(PF_FREEZE);
+ try_to_freeze();
if (!skt->thread)
break;
diff --git a/drivers/pnp/pnpbios/core.c b/drivers/pnp/pnpbios/core.c
index e939c93..778a324 100644
--- a/drivers/pnp/pnpbios/core.c
+++ b/drivers/pnp/pnpbios/core.c
@@ -182,7 +182,7 @@
msleep_interruptible(2000);
if(signal_pending(current)) {
- if (try_to_freeze(PF_FREEZE))
+ if (try_to_freeze())
continue;
break;
}
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index d2d648e..a8d879a 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2808,7 +2808,7 @@
do {
hub_events();
wait_event_interruptible(khubd_wait, !list_empty(&hub_event_list));
- try_to_freeze(PF_FREEZE);
+ try_to_freeze();
} while (!signal_pending(current));
pr_debug ("%s: khubd exiting\n", usbcore_name);
diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index 037a7f1..a9be851 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -1554,8 +1554,7 @@
rc = wait_event_interruptible(fsg->thread_wqh,
fsg->thread_wakeup_needed);
fsg->thread_wakeup_needed = 0;
- if (current->flags & PF_FREEZE)
- refrigerator(PF_FREEZE);
+ try_to_freeze();
return (rc ? -EINTR : 0);
}
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index 35c1ca6..77e7fc2 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -847,10 +847,8 @@
wait_event_interruptible_timeout(us->delay_wait,
test_bit(US_FLIDX_DISCONNECTING, &us->flags),
delay_use * HZ);
- if (current->flags & PF_FREEZE) {
- refrigerator(PF_FREEZE);
+ if (try_to_freeze())
goto retry;
- }
}
/* If the device is still connected, perform the scanning */
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index b460927..312cf32 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -646,7 +646,7 @@
while (!control_needs_exit || have_to_wait) {
have_to_wait = 0;
- try_to_freeze(PF_FREEZE);
+ try_to_freeze();
msleep_interruptible(w1_timeout * 1000);
if (signal_pending(current))
@@ -725,7 +725,7 @@
allow_signal(SIGTERM);
while (!test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
- try_to_freeze(PF_FREEZE);
+ try_to_freeze();
msleep_interruptible(w1_timeout * 1000);
if (signal_pending(current))