* Re: mmotm 2009-08-04-14-22 uploaded
[not found] ` <20090805063946.GA1934@darkstar>
@ 2009-08-05 7:06 ` Andrew Morton
2009-08-05 7:14 ` Eric Dumazet
1 sibling, 0 replies; 4+ messages in thread
From: Andrew Morton @ 2009-08-05 7:06 UTC (permalink / raw)
To: Dave Young; +Cc: linux-kernel, netdev, Peter Zijlstra, Jiri Pirko
On Wed, 5 Aug 2009 14:39:46 +0800 Dave Young <hidave.darkstar@gmail.com> wrote:
> Hi andrew,
>
> I see following lockdep warning with this release:
>
> [ 0.474144] INFO: trying to register non-static key.
> [ 0.474144] the code is fine but needs lockdep annotation.
> [ 0.474144] turning off the locking correctness validator.
> [ 0.474144] Pid: 1, comm: swapper Not tainted 2.6.31-rc5-mm1 #7
> [ 0.474144] Call Trace:
> [ 0.474144] [<c1047f1e>] register_lock_class+0x58/0x241
> [ 0.474144] [<c1049ab1>] __lock_acquire+0xac/0xb73
> [ 0.474144] [<c1076eb5>] ? __alloc_pages_nodemask+0xe2/0x483
> [ 0.474144] [<c1048b64>] ? mark_lock+0x1e/0x1c7
> [ 0.474144] [<c1048b64>] ? mark_lock+0x1e/0x1c7
> [ 0.474144] [<c1048d50>] ? mark_held_locks+0x43/0x5b
> [ 0.474144] [<c10940a6>] ? kmem_cache_alloc+0xac/0x11b
> [ 0.474144] [<c104a615>] lock_acquire+0x9d/0xc0
> [ 0.474144] [<c12b8b96>] ? netif_addr_lock_bh+0xd/0xf
> [ 0.474144] [<c1330feb>] _spin_lock_bh+0x20/0x2f
> [ 0.474144] [<c12b8b96>] ? netif_addr_lock_bh+0xd/0xf
> [ 0.474144] [<c12b8b96>] netif_addr_lock_bh+0xd/0xf
> [ 0.474144] [<c12bc3c3>] alloc_netdev_mq+0xf9/0x1a5
> [ 0.474144] [<c121f016>] ? loopback_setup+0x0/0x74
> [ 0.474144] [<c1578d49>] loopback_net_init+0x20/0x5d
> [ 0.474144] [<c12b7907>] register_pernet_operations+0x13/0x15
> [ 0.474144] [<c12b7970>] register_pernet_device+0x1f/0x47
> [ 0.474144] [<c157ee8d>] net_dev_init+0xfe/0x14d
> [ 0.474144] [<c1001137>] do_one_initcall+0x4a/0x11a
> [ 0.474144] [<c157ed8f>] ? net_dev_init+0x0/0x14d
> [ 0.474144] [<c1067e00>] ? register_irq_proc+0x64/0xa8
> [ 0.474144] [<c1067e97>] ? init_irq_proc+0x53/0x60
> [ 0.474144] [<c1557535>] kernel_init+0x129/0x17a
> [ 0.474144] [<c155740c>] ? kernel_init+0x0/0x17a
> [ 0.474144] [<c1003d47>] kernel_thread_helper+0x7/0x10
At a guess I'd say that alloc_netdev_mq()->dev_unicast_init() is doing
netif_addr_lock_bh()->spin_lock_bh(&dev->addr_list_lock) prior to
initialising add_list_lock.
Something like this might shut it up:
--- a/net/core/dev.c~a
+++ a/net/core/dev.c
@@ -5111,7 +5111,7 @@ struct net_device *alloc_netdev_mq(int s
if (dev_addr_init(dev))
goto free_tx;
- dev_unicast_init(dev);
+ __hw_addr_init(&dev->uc);
dev_net_set(dev, &init_net);
but it'd be better to intialise this thing earlier like:
--- a/net/core/dev.c~a
+++ a/net/core/dev.c
@@ -4730,8 +4730,6 @@ int register_netdevice(struct net_device
BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
BUG_ON(!net);
- spin_lock_init(&dev->addr_list_lock);
- netdev_set_addr_lockdep_class(dev);
netdev_init_queue_locks(dev);
dev->iflink = -1;
@@ -5107,6 +5105,8 @@ struct net_device *alloc_netdev_mq(int s
dev = PTR_ALIGN(p, NETDEV_ALIGN);
dev->padded = (char *)dev - (char *)p;
+ spin_lock_init(&dev->addr_list_lock);
+ netdev_set_addr_lockdep_class(dev);
if (dev_addr_init(dev))
goto free_tx;
_
but that might break register_netdevice() for netdevs which were
allocated via other means, dunno.
I would be pointing fingers at
: commit 31278e71471399beaff9280737e52b47db4dc345
: Author: Jiri Pirko <jpirko@redhat.com>
: AuthorDate: Wed Jun 17 01:12:19 2009 +0000
: Commit: David S. Miller <davem@davemloft.net>
: CommitDate: Thu Jun 18 00:29:08 2009 -0700
:
: net: group address list and its count
and politely suggesting that net developers enable lockdep when testing :)
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: mmotm 2009-08-04-14-22 uploaded
[not found] ` <20090805063946.GA1934@darkstar>
2009-08-05 7:06 ` mmotm 2009-08-04-14-22 uploaded Andrew Morton
@ 2009-08-05 7:14 ` Eric Dumazet
1 sibling, 0 replies; 4+ messages in thread
From: Eric Dumazet @ 2009-08-05 7:14 UTC (permalink / raw)
To: Dave Young
Cc: akpm, mm-commits, linux-kernel, Linux Netdev List,
David S. Miller, Jiri Pirko, Ingo Molnar
Dave Young a écrit :
> Hi andrew,
>
> I see following lockdep warning with this release:
>
> [ 0.474144] INFO: trying to register non-static key.
> [ 0.474144] the code is fine but needs lockdep annotation.
> [ 0.474144] turning off the locking correctness validator.
> [ 0.474144] Pid: 1, comm: swapper Not tainted 2.6.31-rc5-mm1 #7
> [ 0.474144] Call Trace:
> [ 0.474144] [<c1047f1e>] register_lock_class+0x58/0x241
> [ 0.474144] [<c1049ab1>] __lock_acquire+0xac/0xb73
> [ 0.474144] [<c1076eb5>] ? __alloc_pages_nodemask+0xe2/0x483
> [ 0.474144] [<c1048b64>] ? mark_lock+0x1e/0x1c7
> [ 0.474144] [<c1048b64>] ? mark_lock+0x1e/0x1c7
> [ 0.474144] [<c1048d50>] ? mark_held_locks+0x43/0x5b
> [ 0.474144] [<c10940a6>] ? kmem_cache_alloc+0xac/0x11b
> [ 0.474144] [<c104a615>] lock_acquire+0x9d/0xc0
> [ 0.474144] [<c12b8b96>] ? netif_addr_lock_bh+0xd/0xf
> [ 0.474144] [<c1330feb>] _spin_lock_bh+0x20/0x2f
> [ 0.474144] [<c12b8b96>] ? netif_addr_lock_bh+0xd/0xf
> [ 0.474144] [<c12b8b96>] netif_addr_lock_bh+0xd/0xf
> [ 0.474144] [<c12bc3c3>] alloc_netdev_mq+0xf9/0x1a5
> [ 0.474144] [<c121f016>] ? loopback_setup+0x0/0x74
> [ 0.474144] [<c1578d49>] loopback_net_init+0x20/0x5d
> [ 0.474144] [<c12b7907>] register_pernet_operations+0x13/0x15
> [ 0.474144] [<c12b7970>] register_pernet_device+0x1f/0x47
> [ 0.474144] [<c157ee8d>] net_dev_init+0xfe/0x14d
> [ 0.474144] [<c1001137>] do_one_initcall+0x4a/0x11a
> [ 0.474144] [<c157ed8f>] ? net_dev_init+0x0/0x14d
> [ 0.474144] [<c1067e00>] ? register_irq_proc+0x64/0xa8
> [ 0.474144] [<c1067e97>] ? init_irq_proc+0x53/0x60
> [ 0.474144] [<c1557535>] kernel_init+0x129/0x17a
> [ 0.474144] [<c155740c>] ? kernel_init+0x0/0x17a
> [ 0.474144] [<c1003d47>] kernel_thread_helper+0x7/0x10
>
> --
Hmm, it seems addr_list_lock is not initialized at the right place...
commit a6ac65db addded a netif_addr_lock_bh() in dev_unicast_init()
We initialize dev->addr_list_lock in register_netdevice(), we should
init it earlier, right after allocation and before dev_unicast_init()
But dev->type being 0, we probably cannot call netdev_set_addr_lockdep_class()
at this point...
David, what do you think ? Is it safe to call netdev_set_addr_lockdep_class()
in register_netdevice(), after lock being used one time in dev_unicast_init() ?
Thank you
[PATCH] net: Init dev->addr_list_lock in alloc_netdev_mq()
We initialize dev->addr_list_lock in register_netdevice(), we should
init it earlier, right after allocation and before dev_unicast_init()
Reported-by: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
---
diff --git a/net/core/dev.c b/net/core/dev.c
index 43e61ba..e50356b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4728,7 +4728,6 @@ int register_netdevice(struct net_device *dev)
BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
BUG_ON(!net);
- spin_lock_init(&dev->addr_list_lock);
netdev_set_addr_lockdep_class(dev);
netdev_init_queue_locks(dev);
@@ -5106,6 +5105,7 @@ struct net_device *alloc_netdev_mq(int sizeof_priv, const char *name,
dev = PTR_ALIGN(p, NETDEV_ALIGN);
dev->padded = (char *)dev - (char *)p;
+ spin_lock_init(&dev->addr_list_lock);
if (dev_addr_init(dev))
goto free_tx;
^ permalink raw reply related [flat|nested] 4+ messages in thread