numa and taskqueues

[Emeric POUPON]

>>
>> Actually, there is a performance boost only when few flows are involved.
>> That's why this is not activated by default and a sysctl is here to enable the
>> feature.
>>
>> To sum up, the more different flows you process (both ciphered and unciphered),
>> the more network queues are hit and the more CPU units are triggered from
>> ipsec.
>> In this case, we indeed notice a loss, certainly due to the extra
>> queing/reordering performed.
> 
> Can you dig into that a bit more? Do you know exactly what's going on?
> eg, is it a "lock contention" problem? Is it a "stuff is context
> switching, thus latency" problem? etc, etc.
> 

Unfortunately I cannot tell you the exact reason right now.
I am sure there is no lock contention involved though (except of course when several domains are involved).
Did you expect such a dev to be enabled by default?

Emeric