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SubjectRe: Setting monotonic time?
Thomas Gleixner <> 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.


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