Merge pull request #32441 from poettering/rework-handoff-timestamp

pid1: rework handoff timestamp

diff --cc NEWS
index 806fb8abf35ae1878db11f815ca7b123f029932e,ac7f0f1154d01eb897145fe0cf58fed5d892c7ae..38a1abb78cacc8a8eefe7888428b44fb3b002797
--- 1/NEWS
--- 2/NEWS
+++ b/NEWS
@@@ -200,37 -196,15 +200,36 @@@ CHANGES WITH 256-rc1
            PID 1 has successfully completed installation of its various UNIX
            process signal handlers (i.e. the moment where SIGRTMIN+4 sent to
            PID 1 will start to have the effect of shutting down the system
 -          cleanly).
 +          cleanly). X_SYSTEMD_SHUTDOWN= is sent shortly before the system shuts
 +          down, and carries a string identifying the type of shutdown,
 +          i.e. "poweroff", "halt", "reboot". X_SYSTEMD_REBOOT_PARAMETER= is
 +          sent at the same time and carries the string passed to "systemctl
 +          --reboot-argument=" if there was one.
  
-         * New D-Bus properties ExecMainHandoverTimestamp and
-           ExecMainHandoverTimestampMonotonic are now published by services of
-           type exec, dbus, notify, and notify-reload.
-           This timestamp is taken as the very last operation before executing
-           a service's binary, which allows users to accurately track when
-           execution control of the process is handed over from systemd to the
-           payload.
+         * New D-Bus properties ExecMainHandoffTimestamp and
+           ExecMainHandoffTimestampMonotonic are now published by services
+           units. This timestamp is taken as the very last operation before
+           handing off control to invoked binaries. This information is
+           available for other unit types that fork off processes (i.e. mount,
+           swap, socket units), but currently only via "systemd-analyze dump".
  
 +        * An additional timestamp is now taken by the service manager when a
 +          system shutdown operation is initiated. It can be queried via D-Bus
 +          during the shutdown phase. It's passed to the following service
 +          manager invocation on soft reboots, which will then use it to log the
 +          overall "grey-out" time of the soft reboot operation, i.e. the time
 +          when the shutdown began until the system is fully up again.
 +
 +        * "systemctl status" will now display the invocation ID in its usual
 +          output, i.e. the 128bit ID uniquely assigned to the current runtime
 +          cycle of the unit. The ID has been supported for a long time, but is
 +          now more prominently displayed, as it is a very useful handle to a
 +          specific invocation of a service.
 +
 +        * systemd now generates a new "taint" string "unmerged-bin" for systems
 +          that have /usr/bin/ and /usr/sbin/ separate. It's generally
 +          recommended to make the latter a symlink to the former these days.
 +
          Journal:
  
          * systemd-journald can now forward journal entries to a socket