Since the only monotonic clock that can be adjusted by NTP is Linux'
CLOCK_MONOTONIC, if we avoid it, then time.monotonic() would always
give a clock that isn't adjusted by NTP.
I thought we decided that NTP adjustment isn't an issue, because
it's always gradual.
Well, in timings it is an issue, but perhaps not a big one. :-)
In any case, which one we use will not change the API, so if it is
decided it is an issue, we can always more to CLOCK_MONOTONIC_RAW in
the future, once Linux< 2.6.26 (or whatever it was) is deemed
unsupported.
I prefer to use CLOCK_MONOTONIC, not because it is also available for
older Linux kernels, but because it is more reliable. Even if the
underlying clock source is unstable (unstable frequency), a delta of
two reads of the CLOCK_MONOTONIC clock is a result in *seconds*,
whereas CLOCK_MONOTONIC_RAW may use an unit a little bit bigger or
smaller than a second. time.monotonic() unit is the second, as written
in its documentation.