Hello,
I've applied the patch from Stephen on top of the 2.6.0-test1 kernel,
and here is the result :
Jul 14 10:57:01 donald kernel: dst route cache has 0 references
Jul 14 10:57:01 donald kernel: unregister_netdevice: waiting for tap0 to become
free. Usage count = -3
Jul 14 10:57:10 donald kernel: dst route cache has 0 references
Jul 14 10:57:10 donald kernel: unregister_netdevice: waiting for tap0 to become
free. Usage count = -3
Jul 14 10:57:20 donald kernel: dst route cache has 0 references
Jul 14 10:57:20 donald kernel: unregister_netdevice: waiting for tap0 to become
free. Usage count = -3
Jul 14 10:57:31 donald kernel: dst route cache has 0 references
Jul 14 10:57:31 donald kernel: unregister_netdevice: waiting for tap0 to become
free. Usage count = -3
This is a big change compared to 2.5.74 (.75 not tested).
I guess a negative usage count should be considered as valid
by unregister_netdevice.
What about :
--- dev.c 2003-07-14 11:13:23.000000000 +0200
+++ dev.c.orig 2003-07-14 11:13:01.000000000 +0200
@@ -2746,7 +2746,7 @@
unsigned long rebroadcast_time, warning_time;
rebroadcast_time = warning_time = jiffies;
- while (atomic_read(&dev->refcnt) > 0) {
+ while (atomic_read(&dev->refcnt) != 0) {
if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
rtnl_shlock();
rtnl_exlock();
Regards,
Paul
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
REHAB is for quitters.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Paul Rolland, rol@xxxxxxxxx
Witbe.net SA
Directeur Associe
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> -----Original Message-----
> From: Stephen Hemminger [mailto:shemminger@xxxxxxxx]
> Sent: Wednesday, July 09, 2003 8:44 PM
> To: Paul Rolland; cfriesen@xxxxxxxxxxxxxxxxxx; paulus@xxxxxxxxx
> Cc: linux-ppp@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxx
> Subject: Re: [BUG]: problem when shutting down ppp connection
> since 2.5.70
>
>
> The problem is that some protocol is still holding a reference to the
> device. This is a bug in the protocol, and needs to be fixed (ie not a
> ppp bug).
>
> Try building a kernel with only IPv4, eliminate all others then add
> back until you find the culprit.
>
> The following patch may help also.
>
> diff -Nru a/net/core/dev.c b/net/core/dev.c
> --- a/net/core/dev.c Wed Jul 9 11:40:56 2003
> +++ b/net/core/dev.c Wed Jul 9 11:40:56 2003
> @@ -72,6 +72,8 @@
> * - netif_rx() feedback
> */
>
> +#define DEBUG 1
> +
> #include <asm/uaccess.h>
> #include <asm/system.h>
> #include <asm/bitops.h>
> @@ -2704,6 +2706,8 @@
> goto out;
> }
>
> +extern void dst_dumpref(const struct net_device *dev);
> +
> static void netdev_wait_allrefs(struct net_device *dev)
> {
> unsigned long rebroadcast_time, warning_time;
> @@ -2740,6 +2744,30 @@
> current->state = TASK_RUNNING;
>
> if (time_after(jiffies, warning_time + 10 * HZ)) {
> +#ifdef DEBUG
> + dst_dumpref(dev);
> +
> + if (dev->atalk_ptr)
> + printk(KERN_INFO
> "unregister_netdevice: "
> + " %s: probably in use as
> AppleTalk device\n", dev->name);
> + if (dev->ip_ptr)
> + printk(KERN_INFO
> "unregister_netdevice: "
> + " %s: probably in use as
> IPv4 device\n", dev->name);
> +
> + if (dev->atalk_ptr)
> + printk(KERN_INFO
> "unregister_netdevice: "
> + " %s: probably in use as
> DECnet device\n", dev->name);
> + if (dev->ip6_ptr)
> + printk(KERN_INFO
> "unregister_netdevice: "
> + " %s: probably in use as
> IPv6 device\n", dev->name);
> +
> + if (dev->ec_ptr)
> + printk(KERN_INFO
> "unregister_netdevice: "
> + " %s: probably in use as
> Econet device\n", dev->name);
> + if (dev->ax25_ptr)
> + printk(KERN_INFO
> "unregister_netdevice: "
> + " %s: probably in use as
> AX.25 device\n", dev->name); #endif
> printk(KERN_EMERG "unregister_netdevice: "
> "waiting for %s to become free. Usage "
> "count = %d\n",
> diff -Nru a/net/core/dst.c b/net/core/dst.c
> --- a/net/core/dst.c Wed Jul 9 11:40:56 2003
> +++ b/net/core/dst.c Wed Jul 9 11:40:56 2003
> @@ -41,6 +41,21 @@
> static struct timer_list dst_gc_timer =
> TIMER_INITIALIZER(dst_run_gc, 0, DST_GC_MIN);
>
> +
> +void dst_dumpref(const struct net_device *dev)
> +{
> + struct dst_entry *dst;
> + int count = 0;
> +
> + spin_lock_bh(&dst_lock);
> + for (dst = dst_garbage_list; dst; dst = dst->next) {
> + if (dst->dev == dev) ++count;
> + }
> + spin_unlock_bh(&dst_lock);
> +
> + printk(KERN_INFO "dst route cache has %d references\n",
> count); }
> +
> static void dst_run_gc(unsigned long dummy)
> {
> int delayed = 0;
>
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