Andrew Morton a écrit :
> Eric Dumazet <dada1@cosmosbay.com> wrote:
>>> An advantage of retaining a spinlock in percpu_counter is that if accuracy
>>> is needed at a low rate (say, /proc reading) we can take the lock and then
>>> go spill each CPU's local count into the main one.  It would need to be a
>>> very low rate though.   Or we make the cpu-local counters atomic too.
>> We might use atomic_long_t only (and no spinlocks)
> 
> Yup, that's it.
> 
>> Something like this ?
>>
> 
> It'd be a lot neater if we had atomic_long_xchg().

You are my guest :)

[PATCH] Add atomic_long_xchg() and atomic_long_cmpxchg() wrappers

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>