On 5/3/22 10:14, Alistair Popple wrote: > I would certainly be interested in figuring out how HW could provide some sort > of heatmap to identify which pages are hot and which processing unit is using > them. Currently for these systems users have to manually assign memory policy to > get any reasonable performance, both to disable NUMA balancing and make sure > memory is allocated on the right node. Autonuma-induced page faults are a total non-starter for lots of workloads, even ignoring GPUs. Basically anyone who is latency sensitive stays far, far away from autonuma. As for improving on page faults for data collection... *Can* hardware provide this information? Definitely. Have hardware vendors been motivated enough to add hardware to do this? Nope, not yet. Do you know anyone that works for any hardware companies? ;) Seriously, though. Folks at Intel _are_ thinking about this problem. I'm hoping we have hardware some day to help lend a hand. The more hardware vendors that do this, the more likely it is that we'll have good kernel code to consume data from the hardware.
