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: <[email protected]>
---
arch/i386/oprofile/nmi_timer_int.c | 2 +-
arch/ppc64/kernel/HvLpEvent.c | 2 +-
arch/x86_64/kernel/mce.c | 2 +-
drivers/acpi/processor_idle.c | 2 +-
drivers/char/ipmi/ipmi_si_intf.c | 4 ++--
drivers/input/keyboard/atkbd.c | 2 +-
drivers/md/multipath.c | 2 +-
drivers/md/raid1.c | 2 +-
drivers/md/raid10.c | 2 +-
drivers/md/raid5.c | 2 +-
drivers/md/raid6main.c | 2 +-
drivers/net/r8169.c | 2 +-
drivers/s390/cio/airq.c | 4 ++--
kernel/module.c | 2 +-
kernel/profile.c | 2 +-
mm/slab.c | 2 +-
net/core/dev.c | 2 +-
17 files changed, 19 insertions(+), 19 deletions(-)
diff -urpN -X dontdiff linux-2.6.12-rc1/arch/i386/oprofile/nmi_timer_int.c linux-2.6.12-rc1-bettersk/arch/i386/oprofile/nmi_timer_int.c
--- linux-2.6.12-rc1/arch/i386/oprofile/nmi_timer_int.c Tue Mar 1 23:37:52 2005
+++ linux-2.6.12-rc1-bettersk/arch/i386/oprofile/nmi_timer_int.c Fri Apr 1 21:03:57 2005
@@ -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. */
}
diff -urpN -X dontdiff linux-2.6.12-rc1/arch/ppc64/kernel/HvLpEvent.c linux-2.6.12-rc1-bettersk/arch/ppc64/kernel/HvLpEvent.c
--- linux-2.6.12-rc1/arch/ppc64/kernel/HvLpEvent.c Tue Mar 1 23:38:09 2005
+++ linux-2.6.12-rc1-bettersk/arch/ppc64/kernel/HvLpEvent.c Fri Apr 1 20:54:40 2005
@@ -45,7 +45,7 @@ int HvLpEvent_unregisterHandler( HvLpEve
/* 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;
diff -urpN -X dontdiff linux-2.6.12-rc1/arch/x86_64/kernel/mce.c linux-2.6.12-rc1-bettersk/arch/x86_64/kernel/mce.c
--- linux-2.6.12-rc1/arch/x86_64/kernel/mce.c Tue Mar 1 23:37:52 2005
+++ linux-2.6.12-rc1-bettersk/arch/x86_64/kernel/mce.c Fri Apr 1 21:03:01 2005
@@ -392,7 +392,7 @@ static ssize_t mce_read(struct file *fil
memset(mcelog.entry, 0, next * sizeof(struct mce));
mcelog.next = 0;
- synchronize_kernel();
+ synchronize_sched(); /* Allow all already-started MCEs to complete. */
/* Collect entries that were still getting written before the synchronize. */
diff -urpN -X dontdiff linux-2.6.12-rc1/drivers/acpi/processor_idle.c linux-2.6.12-rc1-bettersk/drivers/acpi/processor_idle.c
--- linux-2.6.12-rc1/drivers/acpi/processor_idle.c Tue Mar 1 23:38:25 2005
+++ linux-2.6.12-rc1-bettersk/drivers/acpi/processor_idle.c Sat Apr 2 10:57:37 2005
@@ -838,7 +838,7 @@ int acpi_processor_cst_has_changed (stru
/* 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);
diff -urpN -X dontdiff linux-2.6.12-rc1/drivers/char/ipmi/ipmi_si_intf.c linux-2.6.12-rc1-bettersk/drivers/char/ipmi/ipmi_si_intf.c
--- linux-2.6.12-rc1/drivers/char/ipmi/ipmi_si_intf.c Thu Mar 31 09:53:02 2005
+++ linux-2.6.12-rc1-bettersk/drivers/char/ipmi/ipmi_si_intf.c Fri Apr 1 20:44:59 2005
@@ -2194,7 +2194,7 @@ static int init_one_smi(int intf_num, st
/* 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)
@@ -2307,7 +2307,7 @@ static void __exit cleanup_one_si(struct
/* 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. */
diff -urpN -X dontdiff linux-2.6.12-rc1/drivers/input/keyboard/atkbd.c linux-2.6.12-rc1-bettersk/drivers/input/keyboard/atkbd.c
--- linux-2.6.12-rc1/drivers/input/keyboard/atkbd.c Thu Mar 31 09:53:04 2005
+++ linux-2.6.12-rc1-bettersk/drivers/input/keyboard/atkbd.c Fri Apr 1 21:18:07 2005
@@ -678,7 +678,7 @@ static void atkbd_disconnect(struct seri
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);
diff -urpN -X dontdiff linux-2.6.12-rc1/drivers/md/multipath.c linux-2.6.12-rc1-bettersk/drivers/md/multipath.c
--- linux-2.6.12-rc1/drivers/md/multipath.c Tue Mar 1 23:38:08 2005
+++ linux-2.6.12-rc1-bettersk/drivers/md/multipath.c Fri Apr 1 21:20:08 2005
@@ -355,7 +355,7 @@ static int multipath_remove_disk(mddev_t
goto abort;
}
p->rdev = NULL;
- synchronize_kernel();
+ synchronize_rcu();
if (atomic_read(&rdev->nr_pending)) {
/* lost the race, try later */
err = -EBUSY;
diff -urpN -X dontdiff linux-2.6.12-rc1/drivers/md/raid1.c linux-2.6.12-rc1-bettersk/drivers/md/raid1.c
--- linux-2.6.12-rc1/drivers/md/raid1.c Thu Mar 31 09:53:05 2005
+++ linux-2.6.12-rc1-bettersk/drivers/md/raid1.c Fri Apr 1 21:20:50 2005
@@ -797,7 +797,7 @@ static int raid1_remove_disk(mddev_t *md
goto abort;
}
p->rdev = NULL;
- synchronize_kernel();
+ synchronize_rcu();
if (atomic_read(&rdev->nr_pending)) {
/* lost the race, try later */
err = -EBUSY;
diff -urpN -X dontdiff linux-2.6.12-rc1/drivers/md/raid10.c linux-2.6.12-rc1-bettersk/drivers/md/raid10.c
--- linux-2.6.12-rc1/drivers/md/raid10.c Tue Mar 1 23:38:38 2005
+++ linux-2.6.12-rc1-bettersk/drivers/md/raid10.c Fri Apr 1 21:21:24 2005
@@ -977,7 +977,7 @@ static int raid10_remove_disk(mddev_t *m
goto abort;
}
p->rdev = NULL;
- synchronize_kernel();
+ synchronize_rcu();
if (atomic_read(&rdev->nr_pending)) {
/* lost the race, try later */
err = -EBUSY;
diff -urpN -X dontdiff linux-2.6.12-rc1/drivers/md/raid5.c linux-2.6.12-rc1-bettersk/drivers/md/raid5.c
--- linux-2.6.12-rc1/drivers/md/raid5.c Thu Mar 31 09:53:05 2005
+++ linux-2.6.12-rc1-bettersk/drivers/md/raid5.c Fri Apr 1 21:28:06 2005
@@ -1873,7 +1873,7 @@ static int raid5_remove_disk(mddev_t *md
goto abort;
}
p->rdev = NULL;
- synchronize_kernel();
+ synchronize_rcu();
if (atomic_read(&rdev->nr_pending)) {
/* lost the race, try later */
err = -EBUSY;
diff -urpN -X dontdiff linux-2.6.12-rc1/drivers/md/raid6main.c linux-2.6.12-rc1-bettersk/drivers/md/raid6main.c
--- linux-2.6.12-rc1/drivers/md/raid6main.c Thu Mar 31 09:53:05 2005
+++ linux-2.6.12-rc1-bettersk/drivers/md/raid6main.c Fri Apr 1 21:29:19 2005
@@ -2038,7 +2038,7 @@ static int raid6_remove_disk(mddev_t *md
goto abort;
}
p->rdev = NULL;
- synchronize_kernel();
+ synchronize_rcu();
if (atomic_read(&rdev->nr_pending)) {
/* lost the race, try later */
err = -EBUSY;
diff -urpN -X dontdiff linux-2.6.12-rc1/drivers/net/r8169.c linux-2.6.12-rc1-bettersk/drivers/net/r8169.c
--- linux-2.6.12-rc1/drivers/net/r8169.c Thu Mar 31 09:53:08 2005
+++ linux-2.6.12-rc1-bettersk/drivers/net/r8169.c Fri Apr 1 21:41:38 2005
@@ -2385,7 +2385,7 @@ core_down:
}
/* 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 ?
diff -urpN -X dontdiff linux-2.6.12-rc1/drivers/s390/cio/airq.c linux-2.6.12-rc1-bettersk/drivers/s390/cio/airq.c
--- linux-2.6.12-rc1/drivers/s390/cio/airq.c Tue Mar 1 23:38:17 2005
+++ linux-2.6.12-rc1-bettersk/drivers/s390/cio/airq.c Fri Apr 1 21:44:18 2005
@@ -45,7 +45,7 @@ s390_register_adapter_interrupt (adapter
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 (adapt
ret = -EINVAL;
else {
adapter_handler = NULL;
- synchronize_kernel();
+ synchronize_sched(); /* Allow interrupts to complete. */
ret = 0;
}
sprintf (dbf_txt, "ret:%d", ret);
diff -urpN -X dontdiff linux-2.6.12-rc1/kernel/module.c linux-2.6.12-rc1-bettersk/kernel/module.c
--- linux-2.6.12-rc1/kernel/module.c Thu Mar 31 09:53:21 2005
+++ linux-2.6.12-rc1-bettersk/kernel/module.c Sat Apr 2 10:58:02 2005
@@ -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);
diff -urpN -X dontdiff linux-2.6.12-rc1/kernel/profile.c linux-2.6.12-rc1-bettersk/kernel/profile.c
--- linux-2.6.12-rc1/kernel/profile.c Tue Mar 1 23:38:26 2005
+++ linux-2.6.12-rc1-bettersk/kernel/profile.c Fri Apr 1 21:46:10 2005
@@ -184,7 +184,7 @@ void unregister_timer_hook(int (*hook)(s
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);
diff -urpN -X dontdiff linux-2.6.12-rc1/mm/slab.c linux-2.6.12-rc1-bettersk/mm/slab.c
--- linux-2.6.12-rc1/mm/slab.c Thu Mar 31 09:53:22 2005
+++ linux-2.6.12-rc1-bettersk/mm/slab.c Fri Apr 1 21:50:57 2005
@@ -1656,7 +1656,7 @@ int kmem_cache_destroy (kmem_cache_t * c
}
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.
diff -urpN -X dontdiff linux-2.6.12-rc1/net/core/dev.c linux-2.6.12-rc1-bettersk/net/core/dev.c
--- linux-2.6.12-rc1/net/core/dev.c Thu Mar 31 09:53:22 2005
+++ linux-2.6.12-rc1-bettersk/net/core/dev.c Fri Apr 1 22:25:26 2005
@@ -3077,7 +3077,7 @@ void free_netdev(struct net_device *dev)
void synchronize_net(void)
{
might_sleep();
- synchronize_kernel();
+ synchronize_rcu();
}
/**
Paul E. McKenney <[email protected]> :
> 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.
[...]
> diff -urpN -X dontdiff linux-2.6.12-rc1/drivers/net/r8169.c linux-2.6.12-rc1-bettersk/drivers/net/r8169.c
> --- linux-2.6.12-rc1/drivers/net/r8169.c Thu Mar 31 09:53:08 2005
> +++ linux-2.6.12-rc1-bettersk/drivers/net/r8169.c Fri Apr 1 21:41:38 2005
> @@ -2385,7 +2385,7 @@ core_down:
> }
>
> /* 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 ?
(answering the FIXME)
The race with the irq is handled somewhere else. As the comment suggests,
this part is racing with the hard_start_xmit() handler. If I read correctly
net/core/dev.c::dev_queue_xmit, the code above simply needs the new
synchronize_rcu().
--
Ueimor
On Fri, Apr 08, 2005 at 01:16:53AM +0200, Francois Romieu wrote:
> Paul E. McKenney <[email protected]> :
> > 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.
> [...]
> > diff -urpN -X dontdiff linux-2.6.12-rc1/drivers/net/r8169.c linux-2.6.12-rc1-bettersk/drivers/net/r8169.c
> > --- linux-2.6.12-rc1/drivers/net/r8169.c Thu Mar 31 09:53:08 2005
> > +++ linux-2.6.12-rc1-bettersk/drivers/net/r8169.c Fri Apr 1 21:41:38 2005
> > @@ -2385,7 +2385,7 @@ core_down:
> > }
> >
> > /* 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 ?
>
> (answering the FIXME)
>
> The race with the irq is handled somewhere else. As the comment suggests,
> this part is racing with the hard_start_xmit() handler. If I read correctly
> net/core/dev.c::dev_queue_xmit, the code above simply needs the new
> synchronize_rcu().
That would be good! In your reading of the code, did you verify that
all instances of calls to hard_start_xmit() are in fact under either
rcu_read_lock() or rcu_read_lock_bh()?
Thanx, Paul
[Jeff added to cc list - it's a network driver question]
On Thu, 7 Apr 2005, Paul E. McKenney wrote:
> > >
> > > /* Give a racing hard_start_xmit a few cycles to complete. */
> > > - synchronize_kernel();
I haven't read the whole driver, but what about
spin_unlock_wait(&dev->xmit_lock);
?
hard_start_xmit is called under dev->xmit_lock, waiting until the lock is
free would guarantee that all running instances of hard_start_xmit have
completed.
Jeff: Is that still correct?
--
Manfred
Manfred Spraul <[email protected]> :
> [Jeff added to cc list - it's a network driver question]
[...]
> I haven't read the whole driver, but what about
> spin_unlock_wait(&dev->xmit_lock);
> ?
The race here is a dev->close() against dev->hard_start_xmit() one where
dev->hard_start_xmit() does not do any locking at all.
(so far, so good...)
--
Ueimor
On Sat, 9 Apr 2005, Francois Romieu wrote:
> Manfred Spraul <[email protected]> :
> > [Jeff added to cc list - it's a network driver question]
> [...]
> > I haven't read the whole driver, but what about
> > spin_unlock_wait(&dev->xmit_lock);
> > ?
>
> The race here is a dev->close() against dev->hard_start_xmit() one where
> dev->hard_start_xmit() does not do any locking at all.
>
I always thought that all callers of dev->hard_start_xmit() acquire
dev->xmit_lock before calling hard_start_xmit().
Is that assumption wrong? I think I even rely on that in one of my
drivers.
--
Manfred
Manfred Spraul <[email protected]> :
[...]
> I always thought that all callers of dev->hard_start_xmit() acquire
> dev->xmit_lock before calling hard_start_xmit().
>
> Is that assumption wrong? I think I even rely on that in one of my
> drivers.
Afaik, no, it is right.
This part of the r8169 driver handles the window starting where qdisc_run()
tests netif_queue_stopped() to the spin_trylock(&dev->xmit_lock) in
qdisc_restart: the lock is not taken and dev->hard_start_xmit() will happen
in the near future ("near" or "preempt safe near" is not relevant here).
The driver must wait for the late newcomer to do its whole work before
it can release the Tx ring, whence the former synchronize_kernel().
r8169_down() looks a bit baroque because it can race with the irq handler
or dev->poll() or the recovery timer and none of those spin_locks either.
I may have missed something though. Feel free to educate.
--
Ueimor