[systemd-devel] looking for an 'uptime' value from a journal entry

[Chris Morgan]

Hello.

I'm looking to store some process tick values from /proc/<pid>/stat
into the journal and retrieve them later to look at cpu load. This
information is most useful if I can also retrieve how long the system
has been up since last boot.

>From http://www.freedesktop.org/software/systemd/man/systemd.journal-fields.html#__MONOTONIC_TIMESTAMP=
it looks like __MONOTONIC_TIMESTAMP might be just what I'm looking for
but the information at the start of that section has me wondering if I
can rely on this __MONOTONIC_TIMESTAMP being present for all entries
and use this as the system uptime.

Thoughts?

Chris