systemd System and Service Manager
+CHANGES WITH 243 in spe:
+
+ * The "kernel.pid_max" sysctl is now bumped to 4194304 by default,
+ i.e. the full 22bit range the kernel allows, up from the old 16bit
+ range. This should improve security and robustness a bit, as PID
+ collisions are made less likely (though certainly still
+ possible). There are rumours this might create compatibility
+ problems, though at this moment no practical ones are known to
+ us. Downstream distributions are hence advised to undo this change in
+ their builds if they are concerned about maximum compatibility, but
+ for everybody else we recommend leaving the value bumped. Besides
+ improving security and robustness this should also simplify things as
+ the maximum number of allowed concurrent tasks was previously bounded
+ by both "kernel.pid_max" and "kernel.threads-max" and now only a
+ single knob is left ("kernel.threads-max"). There have been concerns
+ that usability is affected by this change because larger PID numbers
+ are harder to type, but we believe the change from 5 digit PIDs to 7
+ digit PIDs is not too hampering for usability.
+
+ …
+
CHANGES WITH 242:
* In .link files, MACAddressPolicy=persistent (the default) is changed