[ovs-dev] Suspicious rcu_dereference_check() usage.

[Jesse Gross]

On Thu, Sep 29, 2011 at 5:01 PM, Simon Horman <horms at verge.net.au> wrote:
> I noticed this warning this morning while running
> Open vSwitch 1.2.1 on Linux 3.0 in qemu 0.14.1.
>
> I'm unsure if its a known problem/false warning or not.

It's a known false positive - it happened when the checks for
rcu_dereference() started distinguishing between the BH and non-BH
variants of rcu_read_lock().  In all these case, rcu_read_lock_bh() is
held, so it's actually OK.  The plan is to always run with BHs
disabled like the rest of the network stack, which will allow us to
always use rcu_dereference_bh() and avoid these warnings.  However,
there's some code cleanup that needs to take place before that can
happen.