flux v1.33

Release notes:

• Some config keys related to limiting on unfocus were renamed (backward compatibility is kept):
  • cpu-limit -> unfocus-cpu-limit
  • idle -> unfocus-sched-idle
  • mute -> unfocus-mute
  • delay -> limits-delay
    Yeah, those are longer, but config file looks more understandable with these, especially for newbies.
• Now daemon sets SCHED_FIFO scheduling policy to cpulimit and flux-grab-cursor, if possible. For cpulimit, this improves interrupts stability, preventing the limited process from being paused or kept working for longer than expected, what may break limited process stability or cause system-wide performance drops respectively. For flux-grab-cursor, this reduces input lag, as it acts as a bridge between mouse and window. To make that work, you need to add your user to flux group.
• Optimized function responsible for messages, now there is no any subshell, everything is done via printf. That makes messages more lightweight, even with enabled timestamps and colors (those are processed before event reading).
• Solution to print executed command from config file (replacing variable names with their values) has been rewritten from scratch to get rid of subshell ($(bash -c "echo \"$passed_event_command\"")) and make command being shown properly in output/log.
• To improve daemon performace/reduce overhead, usage of other subshells was reduced everywhere where that makes a sense.
• A bunch of other minor fixes and improvements.

P.S.: Performance improvement in daemon is about up to 40%, especially when it handles a lot of opened windows with --hot option.