on Tue, Mar 06, 2001 at 11:21:07AM -0600, Dave Sherohman (esper@sherohman.org) wrote: > On Tue, Mar 06, 2001 at 06:09:41PM +0100, Joris Lambrecht wrote: > > isn't 2.00 more like 2% ? It is US notation where . is a decimal separator. > > Not ? > > You have the notation correct, but load average and CPU utilization are not > directly related. Load average is the average number of processes that are > waiting on system resources over a certain time period; they could be waiting > for CPU, for I/O, or for other resources. (CPU does tend to be the biggest > bottleneck, though, so a basic rule of thumb is that you usually don't want > load to be much greater than the number of CPUs in the box. It *is* CPU. These are processes in the run queue. A process blocked for I/O or another resource is blocked, not runnable (I think, I'm not positive, but I'll bet my morning coffee on it -- which I *really* like, and you'll want to give it to me anyway if I don't get it). The significance of load average is that if you have more runnable processes than CPUs, you have identified a system bottleneck: it's now possible to increase total system throughput by providing either more and/or faster processors. Excessive swapping indicates the system is memory bound. This isn't to say that having a large amount of swapped memory is bad (it may or may not be), but having a large number of processes swapping in and out of memory is bad. Not sure what the metric for I/O bound is. Under Solaris, top would report on I/O wait. I could crack the O'Reilly system performance tuning book and see what it says. If none of the above are evident and things are still too slow, then start optimizing your program(s). > The machine I'm using starts killing off processes if load exceeds 6 > or 7; I wouldn't want to see it hit 100...) It may not be all bad. In certain cases, I believe Apache will spawn large numbers of processes which manage to count against load average. However, total system performance isn't actually negatively effected too much. I once took my UMP PII/180 box to a load of about 30 by running multiple instances of computer v. computer gnuches.... That took a while to clean up. -- Karsten M. Self <kmself@ix.netcom.com> http://kmself.home.netcom.com/ What part of "Gestalt" don't you understand? There is no K5 cabal http://gestalt-system.sourceforge.net/ http://www.kuro5hin.org
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