Hello, Christoph. On Mon, Jul 25, 2016 at 08:48:25AM -0500, Christoph Lameter wrote: > On Fri, 22 Jul 2016, Waiman Long wrote: > > > - Add a new patch to make the percpu head structure cacheline aligned > > to prevent cacheline contention from disrupting the performance > > of nearby percpu variables. > > It would be better not to use the percpu allocation etc for this. > Given the frequency of off node data access I would say that the data > structure does not qualify as per cpu data. You have per cpu data items > yes but this is not used as per cpu data.
I don't get it. What's the harm of using percpu memory here? Other percpu data structures have remote access too. They're to a lower degree but I don't see a clear demarcation line and making addtions per-cpu seems to have significant benefits here. If there's a better way of splitting the list and locking, sure, let's try that but short of that I don't see anything wrong with doing this per-cpu. Thanks. -- tejun
