On 05/21/2018 03:20 PM, Daniel Colascione wrote: >> VMAs consume kernel memory and we can't reclaim them. That's what it >> boils down to. > How is it different from memfd in that respect? I don't really know what you mean. I know folks use memfd to figure out how much memory pressure we are under. I guess that would trigger when you consume lots of memory with VMAs. VMAs are probably the most similar to things like page tables that are kernel memory that can't be directly reclaimed, but do get freed at OOM-kill-time. But, VMAs are a bit harder than page tables because freeing a page worth of VMAs does not necessarily free an entire page.
