On 04.02.2014 [14:39:32 -0600], Christoph Lameter wrote: > On Mon, 3 Feb 2014, Nishanth Aravamudan wrote: > > > Yes, sorry for my lack of clarity. I meant Joonsoo's latest patch for > > the $SUBJECT issue. > > Hmmm... I am not sure that this is a general solution. The fallback to > other nodes can not only occur because a node has no memory as his patch > assumes. Thanks, Christoph. I see your point. Something in this area would be nice, though, as it does produce a fairly significant bump in the slab usage on our test system. > If the target node allocation fails (for whatever reason) then I would > recommend for simplicities sake to change the target node to > NUMA_NO_NODE and just take whatever is in the current cpu slab. A more > complex solution would be to look through partial lists in increasing > distance to find a partially used slab that is reasonable close to the > current node. Slab has logic like that in fallback_alloc(). Slubs > get_any_partial() function does something close to what you want. I apologize for my own ignorance, but I'm having trouble following. Anton's original patch did fallback to the current cpu slab, but I'm not sure any NUMA_NO_NODE change is necessary there. At the point we're deactivating the slab (in the current code, in __slab_alloc()), we have successfully allocated from somewhere, it's just not on the node we expected to be on. So perhaps you are saying to make a change lower in the code? I'm not sure where it makes sense to change the target node in that case. I'd appreciate any guidance you can give. Thanks, Nish -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>