From: Maxim Uvarov <maxim.uvarov@oracle.com>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH] bond_alb: do not disable BH under netpoll
Date: Wed, 04 Jan 2012 11:35:59 -0800 [thread overview]
Message-ID: <4F04AA1F.10004@oracle.com> (raw)
In-Reply-To: <20120104.132510.1521809723158602749.davem@davemloft.net>
On 01/04/2012 10:25 AM, David Miller wrote:
> From: Maxim Uvarov<maxim.uvarov@oracle.com>
> Date: Wed, 04 Jan 2012 00:14:39 -0800
>
>> On 03.01.2012 18:49, David Miller wrote:
>>> From: Maxim Uvarov<maxim.uvarov@oracle.com>
>>> Date: Tue, 3 Jan 2012 18:20:18 -0800
>>>
>>>> Do not disable BH if interrupts are already disabled
>>>> (netpoll case).
>>>> Signed-off-by: Maxim Uvarov<maxim.uvarov@oracle.com>
>>> Barf...
>>>
>>> We should never use conditional locking like this.
>>
>>
>> How about change spin_lock_bh to spin_lock_irqsave at this place?
>
> Then it's ambiguous whether it's a softirq safe lock or a hardirq
> safe one.
>
> It's just another way to make the locking inconsistent.
at bond_start_xmit() there is check if it's netpoll or not:
/*
* If we risk deadlock from transmitting this in the
* netpoll path, tell netpoll to queue the frame for later tx
*/
if (is_netpoll_tx_blocked(dev))
return NETDEV_TX_BUSY;
which is in the end:
static inline int netpoll_tx_running(struct net_device *dev)
{
return irqs_disabled();
}
So the original patch was in the way as it already implemented.
BTW,
I'm trying to remove warning generated by local_bh_enable_ip:
http://marc.info/?l=linux-netdev&m=132528368523980&w=2
Maxim.
prev parent reply other threads:[~2012-01-04 19:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-04 2:20 [PATCH] bond_alb: do not disable BH under netpoll Maxim Uvarov
2012-01-04 2:49 ` David Miller
2012-01-04 8:14 ` Maxim Uvarov
2012-01-04 18:25 ` David Miller
2012-01-04 19:35 ` Maxim Uvarov [this message]
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