I'd like to propose this as a a BoF for MM. We can find issues if we test them, but some bugs are hard to reproduce, specially some mm bugs. How far are we willing to add knobs to help with synthetic tests which which may not apply to numa for instance? An example is the recent patch I just posted to force testing page migration [0]. We can only run that test if we have a numa system, and a lot of testing today runs on guests without numa. Would we be willing to add a fake numa node to help with synthetic tests like page migration? Then what else could we add to help stress test page migration and compaction further? We already have generic/750 and that has found some snazzy issues so far. But what else can we do to help random guests all over running fstests start covering complex mm tests better? [0] https://lore.kernel.org/r/20250326185101.2237319-1-mcgrof@xxxxxxxxxx Luis