Linus Torvalds wrote on Thu, Jan 10, 2019: > (Except, of course, if somebody actually notices outside of tests. > Which may well happen and just force us to revert that commit. But > that's a separate issue entirely). Both Dave and I pointed at a couple of utilities that break with this. nocache can arguably work with the new behaviour but will behave differently; vmtouch on the other hand is no longer able to display what's in cache or not - people use that for example to "warm up" a container in page cache based on how it appears after it had been running for a while is a pretty valid usecase to me. >From the list Kevin harvested out of the debian code search, the postgresql use case is pretty similar - probe what pages of the database were in cache at shutdown so when you restart it you can preload these and reach "cruse speed" faster. Sure that's probably not billions of users but this all looks fairly valid to me... -- Dominique
