[PATCH] Change synchronize_kernel to _rcu and _sched

This patch changes calls to synchronize_kernel(), deprecated in the earlier
"Deprecate synchronize_kernel, GPL replacement" patch to instead call the new
synchronize_rcu() and synchronize_sched() APIs.

Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/i386/oprofile/nmi_timer_int.c

@@ -36,7 +36,7 @@ static void timer_stop(void)
 {
 	enable_timer_nmi_watchdog();
 	unset_nmi_callback();
-	synchronize_kernel();
+	synchronize_sched();  /* Allow already-started NMIs to complete. */
 }
 
 

arch/ppc64/kernel/HvLpEvent.c

@@ -45,7 +45,7 @@ int HvLpEvent_unregisterHandler( HvLpEvent_Type eventType )
 			/* We now sleep until all other CPUs have scheduled. This ensures that
 			 * the deletion is seen by all other CPUs, and that the deleted handler
 			 * isn't still running on another CPU when we return. */
-			synchronize_kernel();
+			synchronize_rcu();
 		}
 	}
 	return rc;

drivers/acpi/processor_idle.c

@@ -838,7 +838,7 @@ int acpi_processor_cst_has_changed (struct acpi_processor *pr)
 
 	/* Fall back to the default idle loop */
 	pm_idle = pm_idle_save;
-	synchronize_kernel();
+	synchronize_sched();  /* Relies on interrupts forcing exit from idle. */
 
 	pr->flags.power = 0;
 	result = acpi_processor_get_power_info(pr);

drivers/char/ipmi/ipmi_si_intf.c

@@ -2199,7 +2199,7 @@ static int init_one_smi(int intf_num, struct smi_info **smi)
 	/* Wait until we know that we are out of any interrupt
 	   handlers might have been running before we freed the
 	   interrupt. */
-	synchronize_kernel();
+	synchronize_sched();
 
 	if (new_smi->si_sm) {
 		if (new_smi->handlers)
@@ -2312,7 +2312,7 @@ static void __exit cleanup_one_si(struct smi_info *to_clean)
 	/* Wait until we know that we are out of any interrupt
 	   handlers might have been running before we freed the
 	   interrupt. */
-	synchronize_kernel();
+	synchronize_sched();
 
 	/* Wait for the timer to stop.  This avoids problems with race
 	   conditions removing the timer here. */

drivers/input/keyboard/atkbd.c

@@ -678,7 +678,7 @@ static void atkbd_disconnect(struct serio *serio)
 	atkbd_disable(atkbd);
 
 	/* make sure we don't have a command in flight */
-	synchronize_kernel();
+	synchronize_sched();  /* Allow atkbd_interrupt()s to complete. */
 	flush_scheduled_work();
 
 	device_remove_file(&serio->dev, &atkbd_attr_extra);

drivers/md/multipath.c

@@ -355,7 +355,7 @@ static int multipath_remove_disk(mddev_t *mddev, int number)
 			goto abort;
 		}
 		p->rdev = NULL;
-		synchronize_kernel();
+		synchronize_rcu();
 		if (atomic_read(&rdev->nr_pending)) {
 			/* lost the race, try later */
 			err = -EBUSY;

drivers/md/raid1.c

@@ -797,7 +797,7 @@ static int raid1_remove_disk(mddev_t *mddev, int number)
 			goto abort;
 		}
 		p->rdev = NULL;
-		synchronize_kernel();
+		synchronize_rcu();
 		if (atomic_read(&rdev->nr_pending)) {
 			/* lost the race, try later */
 			err = -EBUSY;

drivers/md/raid10.c

@@ -977,7 +977,7 @@ static int raid10_remove_disk(mddev_t *mddev, int number)
 			goto abort;
 		}
 		p->rdev = NULL;
-		synchronize_kernel();
+		synchronize_rcu();
 		if (atomic_read(&rdev->nr_pending)) {
 			/* lost the race, try later */
 			err = -EBUSY;

drivers/md/raid5.c

@@ -1873,7 +1873,7 @@ static int raid5_remove_disk(mddev_t *mddev, int number)
 			goto abort;
 		}
 		p->rdev = NULL;
-		synchronize_kernel();
+		synchronize_rcu();
 		if (atomic_read(&rdev->nr_pending)) {
 			/* lost the race, try later */
 			err = -EBUSY;

drivers/md/raid6main.c

@@ -2038,7 +2038,7 @@ static int raid6_remove_disk(mddev_t *mddev, int number)
 			goto abort;
 		}
 		p->rdev = NULL;
-		synchronize_kernel();
+		synchronize_rcu();
 		if (atomic_read(&rdev->nr_pending)) {
 			/* lost the race, try later */
 			err = -EBUSY;

drivers/net/r8169.c

@@ -2385,7 +2385,7 @@ static void rtl8169_down(struct net_device *dev)
 	}
 
 	/* Give a racing hard_start_xmit a few cycles to complete. */
-	synchronize_kernel();
+	synchronize_sched();  /* FIXME: should this be synchronize_irq()? */
 
 	/*
 	 * And now for the 50k$ question: are IRQ disabled or not ?

drivers/s390/cio/airq.c

@@ -45,7 +45,7 @@ s390_register_adapter_interrupt (adapter_int_handler_t handler)
 	else
 		ret = (cmpxchg(&adapter_handler, NULL, handler) ? -EBUSY : 0);
 	if (!ret)
-		synchronize_kernel();
+		synchronize_sched();  /* Allow interrupts to complete. */
 
 	sprintf (dbf_txt, "ret:%d", ret);
 	CIO_TRACE_EVENT (4, dbf_txt);
@@ -65,7 +65,7 @@ s390_unregister_adapter_interrupt (adapter_int_handler_t handler)
 		ret = -EINVAL;
 	else {
 		adapter_handler = NULL;
-		synchronize_kernel();
+		synchronize_sched();  /* Allow interrupts to complete. */
 		ret = 0;
 	}
 	sprintf (dbf_txt, "ret:%d", ret);

kernel/module.c

@@ -1801,7 +1801,7 @@ sys_init_module(void __user *umod,
 		/* Init routine failed: abort.  Try to protect us from
                    buggy refcounters. */
 		mod->state = MODULE_STATE_GOING;
-		synchronize_kernel();
+		synchronize_sched();
 		if (mod->unsafe)
 			printk(KERN_ERR "%s: module is now stuck!\n",
 			       mod->name);

kernel/profile.c

@@ -184,7 +184,7 @@ void unregister_timer_hook(int (*hook)(struct pt_regs *))
 	WARN_ON(hook != timer_hook);
 	timer_hook = NULL;
 	/* make sure all CPUs see the NULL hook */
-	synchronize_kernel();
+	synchronize_sched();  /* Allow ongoing interrupts to complete. */
 }
 
 EXPORT_SYMBOL_GPL(register_timer_hook);

mm/slab.c

@@ -1666,7 +1666,7 @@ int kmem_cache_destroy(kmem_cache_t * cachep)
 	}
 
 	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU))
-		synchronize_kernel();
+		synchronize_rcu();
 
 	/* no cpu_online check required here since we clear the percpu
 	 * array on cpu offline and set this to NULL.

net/core/dev.c

@@ -3091,7 +3091,7 @@ void free_netdev(struct net_device *dev)
 void synchronize_net(void) 
 {
 	might_sleep();
-	synchronize_kernel();
+	synchronize_rcu();
 }
 
 /**