On Mon, Apr 04, 2016 at 01:21:38PM -0500, Josh Poimboeuf wrote: > Hm, can you explain why it should be copied from the parent? > > I'm thinking the above code is correct for today, but it should still be > changed to be more future-proof. > > Here's my thinking: > > A forked task starts out with no stack, so if I understand correctly, it > can safely start out in the goal universe, regardless of which universe > its parent belongs to. > > However, the current ret_from_fork code is a mess, and Andy Lutomirski > has mentioned that he would like to give newly forked tasks a proper > stack such that instead of jumping to ret_from_fork, they would just > return from schedule(). In that case, it would no longer be safe to > start the new task in the goal universe because it could be "sleeping" > on a to-be-patched function. > > So for proper future proofing, newly forked tasks should be started in > the initial universe (rather than starting in the goal universe or > inheriting the parent's universe). They can then be transitioned over > to the goal universe like any other task. How does that sound? How could a newly forked task start in the old universe if its parent has already been migrated? Any context it inherits will already be from the new universe. -- Vojtech Pavlik Director SuSE Labs -- To unsubscribe from this list: send the line "unsubscribe live-patching" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
