Messages in this thread | | | Subject | Re: Scheduling Times --- Revisited | Date | Wed, 30 Sep 1998 16:17:19 +0800 | From | David Luyer <> |
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> David Luyer <luyer@ucs.uwa.edu.au> writes: > > > Maybe a cron daemon with a syntax which lets you specify that when the load > > avg is over X (say, 0.95) re-check the load average every Y minutes up to a > > maximum of Z minutes (at which time the job is either run or thrown away). > > Therein lies madness. Somebody is running a screensaver, and that other > guy accidentally started two rc5 crackers. Tough luck, no backups this > week.
Hence the maximum time after which the job is run anyway. The main idea being that in the common desktop machine case you can prevent cron jobs executing at an inconvenient time. "this job should run at midnight but if the machine is still busy then, run it any time up to 3am, if it's still busy at 3am just run it anyway" is an example of what I've already said above.
It's not something I'd even consider on any of my servers. I _know_ exactly when I want jobs to run. I'd rather tell people "the performance will be bad at time X" than tell the job not to run when the server is loaded. But in the home machine case there is obviously some case for it. The other alternative (and the only reason this thread could even be possibly on-topic) is to run CPU-intensive console games and CD burners as RT tasks and try to prevent other tasks affecting them. But if the tasks contains lots of disk I/O even if it's niced it may still have to much effect and wreck the CD.
David.
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