[ovs-dev] [PATCH net] openvswitch: fix a possible deadlock and lockdep warning

[David Miller]

From: Flavio Leitner <fbl at redhat.com>
Date: Thu, 27 Mar 2014 09:53:56 -0300

> There are two problematic situations.
> 
> A deadlock can happen when is_percpu is false because it can get
> interrupted while holding the spinlock. Then it executes
> ovs_flow_stats_update() in softirq context which tries to get
> the same lock.
> 
> The second sitation is that when is_percpu is true, the code
> correctly disables BH only for the local CPU, but that confuses
> lockdep enough to trigger the warning below.
> 
> This patch disables BH for both cases fixing the real deadlock
> and the lockdep warning message.
 ...
> Signed-off-by: Flavio Leitner <fbl at redhat.com>

I'll let Jesse review and pick this up.