On Wed, Jul 03, 2024 at 01:47:23PM -0700, Andrii Nakryiko wrote: > > When I cobble all that together (it really shouldn't be one patch, but > > you get the idea I hope) it looks a little something like the below. > > > > I *think* it should work, but perhaps I've missed something? > > Well, at the very least you missed that we can't delay SRCU (or any > other sleepable RCU flavor) potentially indefinitely for uretprobes, > which are completely under user space control. Sure, but that's fixable. You can work around that by having (u)tasks with a non-empty return_instance list carry a timer. When/if that timer fires, it goes and converts the SRCU references to actual references. Not so very hard to do, but very much not needed for a PoC.