Setting monotonic time?

[Eric W. Biederman]

In the context of process migration there is a simpler subproblem that I
think it is worth exploring if we can do something about.

For a cluster of machines all running with synchronized
clocks. CLOCK_REALTIME matches. CLOCK_MONOTNIC does not match between
machines.   Not having a matching CLOCK_MONOTONIC prevents successful
process migration between nodes in that cluster.

Would it be possible to allow setting CLOCK_MONOTONIC at the very
beginning of time?  So that all of the nodes in a cluster can be in
sync?

No change in skew just in offset for CLOCK_MONOTONIC.

There are also dragons involved in coordinating things so that
CLOCK_MONOTONIC gets set before CLOCK_MONOTONIC gets used.  So I don't
know if allowing CLOCK_MONOTONIC to be set would be practical but it
seems work exploring all on it's own.

Dmitry would setting CLOCK_MONOTONIC exactly once at boot time solve
your problem that is you are looking at a time namespace to solve?

Eric