Re: [RFC HACK] xfrm: make state refcounting percpu

[Eric Dumazet]

On 5/3/19 2:07 AM, Steffen Klassert wrote:
> On Wed, Apr 24, 2019 at 12:40:23PM +0200, Florian Westphal wrote:
>> I'm not sure this is a good idea to begin with, refcount
>> is right next to state spinlock which is taken for both tx and rx ops,
>> plus this complicates debugging quite a bit.
> 
> 


For some reason I have not received Florian response.

Florian, when the percpu counters are in nominal mode,
the updates are only in percpu memory, so the cache line containing struct 
percpu_ref in the
main object is not dirtied.

(This field/object can be placed in a read-mostly location of the structure if 
needed)

I would definitely try to use this.