* Ingo Molnar <mingo@xxxxxxxxxx> wrote: > This is an entirely valid line of inquiry IMO. Btw., what I did was to simply look at David's profile on the regressing system and I compared it to the profile I got on a pretty similar (but unfortunately not identical and not regressing) system. I saw 3 differences: - the numa emulation faults - the higher TLB miss cost - numa/core's failure to handle 4K pages properly And addressed those, in the hope of one of them making a difference. There's a fourth line of inquiry I'm pursuing as well: the node assymetry that David and Paul mentioned could have a performance effect as well - resulting from non-ideal placement under numa/core. That is not easy to cure - I have written a patch to take the node assymetry into consideration, I'm still testing it with David's topology simulated on a testbox: numa=fake=4:10,20,20,30,20,10,20,20,20,20,10,20,30,20,20,10 Will send the patch out later. Thanks, Ingo -- 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>