Re: [Y2038][time namespaces] Question regarding CLOCK_REALTIME support plans in Linux time namespaces

[Thomas Gleixner]

Lukasz,

On Fri, Oct 30 2020 at 11:02, Lukasz Majewski wrote:
> I do have a question regarding the Linux time namespaces in respect of
> adding support for virtualizing the CLOCK_REALTIME.
>
> According to patch description [1] and time_namespaces documentation
> [2] the CLOCK_REALTIME is not supported (for now?) to avoid complexity
> and overhead in the kernel.
>
> Is there any plan to add support for it in a near future?

Not really. Just having an offset on clock realtime would be incorrect
in a number of ways. Doing it correct is a massive trainwreck.

For a debug aid, which is what you are looking for, the correctness
would not really matter, but providing that is a really slippery
slope.

If at all we could hide it under a debug option which depends on
CONFIG_BROKEN and emitting a big fat warning in dmesg with a clear
statement that it _is_ broken, stays so forever and any attempt to "fix"
it results in a permanent ban from all kernel lists.

Preferrably we don't go there.

Thanks,

        tglx