As part of the memory management changes expected to be merged for the upcoming Linux 6.11 cycle is allowing more fine-tuned control over the swappiness setting used to determine how aggressively pages are swapped out of physical system memory and into the on-disk swap space.
With the new code from Meta, a swappiness argument is supported for memory.reclaim. This effectively allows more finer-grained control over the swapiness behavior without overriding the global swappiness setting.
TL;DR - We can now control swappiness per cgroup instead of just globally. This is something that userspace oom killers will want to use.