On Tue 21-08-18 17:30:11, Vlastimil Babka wrote: [...] > Frankly, I would rather go with this option and assume that if someone > explicitly wants THP's, they don't care about NUMA locality that much. Yes. And if they do care enough to configure for heavier fault-in treatment then they also can handle numa policy as well. > (Note: I hate __GFP_THISNODE, it's an endless source of issues.) Absolutely. It used to be a slab thing but then found an interesting abuse elsewhere. Like here for the THP. I am pretty sure that the intention was not to stick to a specific node but rather all local nodes within the reclaim distance (or other unit to define that nodes are sufficiently close). > Trying to be clever about "is there still PAGE_SIZEd free memory in the > local node" is imperfect anyway. If there isn't, is it because there's > clean page cache that we can easily reclaim (so it would be worth > staying local) or is it really exhausted? Watermark check won't tell... Exactly. -- Michal Hocko SUSE Labs
