Re: [PATCH] Make highly niced processes run only when idle

[Steve Bergman]

I'm not a kernel hacker by any stretch of the imagination but I do
follow lkml.  While SCHED_IDLE would be really nice it seems like this
topic comes up from time to time there always seems to be a (deadlock)
catch that keeps it from getting into the main kernel tree.  While it
would be really great if Robert's patch turns out to be the magic bullet
this time, as a Linux user and SetiAtHome supporter I would be happy
just to have a "nice -19" that was truly nice.  Running setiathome at
nice -19 on my box and then firing up a processor intensive process at
normal priority, I find that seti still uses 14% processor according to
top.  I like to run 2 setiathome processes because I get better overall
throughput that way, but the 2 combined then get ~25% of the processor.
Not really all that nice.  Would it be difficult to make "19" a special
case that was really, really nice, but not *totally* nice?  Avoiding
deadlock but still following the spirit of SCHED_IDLE?