ditto@cbmvax.UUCP (Michael "Ford" Ditto) (09/29/88)
In article <359@gizzmo.UUCP> Kdavid@gizzmo.UUCP (David Solan) writes: > Another question that has always bothered me is the staying >power of shell windows with jobs running in the background under them. >If you hit Ctrl-d or enter exit for a shell window with jobs still >running in its background, the window stays there, frozen, until all >its background jobs end. Of course nohup(1) can prevent this, but >what is happening here? Why isn't a hangup signal sent and then the >window simply killed? And come to think of it, how DOES nohup get >around it, crafty devil that it is??? Well, the window isn't exactly frozen ... it still has commands running "in" it. The window will stay around as long as some process has it open. nohup redirects stdin/out/err to nohup.out, so nohup'ed processes don't have the window open. When you exit the top-level shell in a window, a SIGHUP should be sent to the process group; perhaps your shell has its background processes ignore SIGHUP or puts them in a separate process group (ksh does the latter, sh does neither). I'd say use nohup if you want them to stay around, or start them from a bourne shell if you want them to automatically go away when you exit. [ ... ] > I would like very much to boost >up nbuf (the number of 1024 byte buffer areas holding disk blocks in >core so that the hard disk doesn't have to be accessed so often) with >ktune to 200 or 300 or more, but no can do. The highest you can go to >is to about 110 or 120. The regular amount is 100. Big deal. Are you saying the ktune command has some limit to nbuf? The manual says "25 up to system capacity". Are you sure you have enough memory for more bufs? (At boot time, the system automatically trims down the number until it fits). > The difference in execution times >between nice -19 and its diametric counterpart, nice --19, is about >15% for 2 jobs running simultaneously on the UNIX PC. It just wasn't meant for anything more than that... perhaps this is a good topic for comp.unix.wizards, since it is something which was designed into Unix. >24 million Americans will die in the next 10 years without their >seat belts on. Buckle up now! I'd guess a much, much larger number than that, unless you are only counting ones who are in cars at the time ... :-) :-) -- -=] Ford [=- "The number of Unix installations (In Real Life: Mike Ditto) has grown to 10, with more expected." ford@kenobi.cts.com - The Unix Programmer's Manual, ...!sdcsvax!crash!elgar!ford 2nd Edition, June, 1972. ditto@cbmvax.commodore.com