Comment by pknopf

Imagine a juggler, juggling 5 balls at a time. At a set period of time, he will drop one ball and accept another ball thrown at him. He handles this very well because there is order/cadence.

Now imagine asking him to support being thrown balls randomly, at any interval. He may make it work, but I'd imagine he will stutter a bit.

In my experience, anytime you interrupt the page cache's normal routine, it stutters everything. I've seen the "sync" command freeze my Ubuntu machine (music player, GUI, etc).

I work on embedded devices, and my employer wanted to reduce the window at which data-loss would happen for 30mb+ files (video capture). It wasn't a supported use case, "But why not! It makes our product theoretically better!" I put my foot down. We aren't touching page-cache until there is a clear benefit to the user. It almost got me fired, but good riddance if so.