Thomas Gleixner <tglx@xxxxxxxxxxxxx> writes: > On Wed, 3 Oct 2018, Eric W. Biederman wrote: >> Direct access to hardware/drivers and not through an abstraction like >> the vfs (an abstraction over block devices) can legitimately be handled >> by hotplug events. I unplug one keyboard I plug in another. >> >> I don't know if the input layer is more of a general abstraction >> or more of a hardware device. I have not dug into it but my guess >> is abstraction from what I have heard. >> >> The scary difficulty here is if after restart input is reporting times >> in CLOCK_MONOTONIC and the applications in the namespace are talking >> about times in CLOCK_MONOTONIC_SYNC. Then there is an issue. As even >> with a fixed offset the times don't match up. >> >> So a time namespace absolutely needs to do is figure out how to deal >> with all of the kernel interfaces reporting times and figure out how to >> report them in the current time namespace. > > So you want to talk to Arnd who is leading the y2038 effort. He knowns how > many and which interfaces are involved aside of the obvious core timer > ones. It's quite an amount and the problem is that you really need to do > that at the interface level, because many of those time stamps are taken in > contexts which are completely oblivious of name spaces. Ditto for timeouts > and similar things which are handed in through these interfaces. Yep. That sounds right. Eric