[ovs-dev] [PATCH net-next 08/11] openvswitch: Per cpu flow stats.

[Jesse Gross]

On Tue, Oct 29, 2013 at 7:11 PM, David Miller <davem at davemloft.net> wrote:
> From: Jesse Gross <jesse at nicira.com>
> Date: Tue, 29 Oct 2013 17:22:21 -0700
>
>> From: Pravin B Shelar <pshelar at nicira.com>
>>
>> With mega flow implementation ovs flow can be shared between
>> multiple CPUs which makes stats updates highly contended
>> operation. Following patch allocates separate stats for each
>> CPU to make stats update scalable.
>>
>> Signed-off-by: Pravin B Shelar <pshelar at nicira.com>
>> Signed-off-by: Jesse Gross <jesse at nicira.com>
>
> Please properly use __percpu memory for this.
>
> Using arrays for this is very strongly discouraged, please instead
> use the kernel facility designed exactly for this.

Pravin had some concerns about the effects of high churn rate on the
percpu allocator, which is why he did it this way initially. I'm going
to drop this patch for now and send out the rest of the series while
he investigates further.