I figure sooneror later we'll have more of these docs, hence let's give
them a clean place to be.
This leaves NEWS and README/README.md as well as the LICENSE texts in
the root directory of the project since that appears to be customary for
Free Software projects.
After discussions with @htejun it appears it's OK now to enable memory
accounting by default for all units without affecting system performance
too badly. facebook has made good experiences with deploying memory
accounting across their infrastructure.
This hence turns MemoryAccounting= from opt-in to opt-out, similar to
how TasksAccounting= is already handled. The other accounting options
remain off, their performance impact is too big still.
CHANGE OF BEHAVIOUR — with this commit "f" line's behaviour is altered
to match what the documentation says: if an "argument" string is
specified it is written to the file only when the file didn't exist
before. Previously, it would be appended to the file each time
systemd-tmpfiles was invoked — which is not a particularly useful
behaviour as the tool is not idempotent then and the indicated files
grow without bounds each time the tool is invoked.
I did some spelunking whether this change in behaviour would break
things, but afaics nothing relies on the previous O_APPEND behaviour of
this line type, hence I think it's relatively safe to make "f" lines
work the way the docs say, rather than adding a new modifier for it or
so.
Triggered by:
https://lists.freedesktop.org/archives/systemd-devel/2018-January/040171.html
With Type=notify services, EXTEND_TIMEOUT_USEC= messages will delay any startup/
runtime/shutdown timeouts.
A service that hasn't timed out, i.e, start time < TimeStartSec,
runtime < RuntimeMaxSec and stop time < TimeoutStopSec, may by sending
EXTEND_TIMEOUT_USEC=, allow the service to continue beyond the limit for
the execution phase (i.e TimeStartSec, RunTimeMaxSec and TimeoutStopSec).
EXTEND_TIMEOUT_USEC= must continue to be sent (in the same way as
WATCHDOG=1) within the time interval specified to continue to reprevent
the timeout from occuring.
Watchdog timeouts are also extended if a EXTEND_TIMEOUT_USEC is greater
than the remaining time on the watchdog counter.
Fixes#5868.
The code intentionally ignored unknown specifiers, treating them as text. This
needs to change because otherwise we can never add a new specifier in a backwards
compatible way. So just treat an unknown (potential) specifier as an error.
In principle this is a break of backwards compatibility, but the previous
behaviour was pretty much useless, since the expanded value could change every
time we add new specifiers, which we do all the time.
As a compromise for backwards compatibility, only fail on alphanumerical
characters. This should cover the most cases where an unescaped percent
character is used, like size=5% and such, which behave the same as before with
this patch. OTOH, this means that we will not be able to use non-alphanumerical
specifiers without breaking backwards compatibility again. I think that's an
acceptable compromise.
v2:
- add NEWS entry
v3:
- only fail on alphanumerical
This fixes various typos, removes some duplications, and adds a bit more
detail in the few places which are potential pitfalls for users.
Also change the way the paragraphs about new options begin, because having
a paragraph saying "Two new options have been added", and then bit lower
again "Two new options have been added" is confusing.
