On 09/02/2014 03:18 PM, Johannes Weiner wrote:
> Accounting new pages is buffered through per-cpu caches, but taking
> them off the counters on free is not, so I'm guessing that above a
> certain allocation rate the cost of locking and changing the counters
> takes over.  Is there a chance you could profile this to see if locks
> and res_counter-related operations show up?

It looks pretty much the same, although it might have equalized the
charge and uncharge sides a bit.  Full 'perf top' output attached.