I noticed something odd while playing around trying to figure out why my
first Celeron is getting warmer than my second Celeron doing the same
thing...If I run the following on standard 2.2.6:
nice --99 perl -e 'a:goto a' &
perl -e 'a:select "","","",0.01;print STDERR ".";goto a'
...the pattern of periods appearing seems to be chunky and it looks as if
the second process is unable to run even when there is one CPU available
and the first process should be able to run on the other. It looks
exactly as if there is only one CPU in the system.
Removing the "nice --99" makes it appear to run smoothly, and not removing
it and adding the same to the second process seems to run smoothly after
an initial pause -- this doesn't make much sense to me. Nothing else is
running on the system...
I applied Andrea's patch to see if it made any difference, and it now
seems to be smooth regardless of the nice value anywhere. Does this make
any sense?
-- Note: The processes I was playing with also stopped bouncing after I applied the patch, as Andrea tried to accomplish. I did like a little bit of bouncing (perhaps once every 10-30 seconds) because it would help keep my CPUs cooler by spreading out a single busy process. I wonder if purposely shuffling the CPU for a process every so often would be worth it -- if it helps prolong the life of the CPUs in a machine a bit longer, it could be good; and, if it's once ever half minute or so, I doubt the cache loss would be noticeable...but then it could also be regarded as unnecessary bloat. Hmm... :)Simon-
| Simon Kirby | Systems Administration | | mailto:sim@netnation.com | NetNation Communications | | http://www.netnation.com/ | Tech: (604) 684-6892 |
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