On Mon, 5 Dec 2011, Alex,Shi wrote: > Previous testing depends on 3.2-rc1, that show hackbench performance has > no clear change, and netperf get some benefit. But seems after > irqsafe_cpu_cmpxchg patch, the result has some change. I am collecting > these results. > netperf will also degrade with this change on some machines, there's no clear heuristic that can be used to benefit all workloads when deciding where to add a partial slab into the list. Cache hotness is great but your patch doesn't address situations where frees happen to a partial slab such that they may be entirely free (or at least below your 1:4 inuse to nr_objs threshold) at the time you want to deactivate the cpu slab. I had a patchset that iterated the partial list and found the "most free" partial slab (and terminated prematurely if a threshold had been reached, much like yours) and selected that one, and it helped netperf 2-3% in my testing. So I disagree with determining where to add a partial slab to the list at the time of free because it doesn't infer its state at the time of cpu slab deactivation. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>