Confirmation Needed - Run Queues include both running and waiting processes

From: <Christopher.Taylor2_at_parallon.net>
Date: Thu, 7 Mar 2013 10:10:30 -0600
Message-ID: <F05D8DF1FB25F44085DB74CB916678E88582D52427_at_NADCWPMSGCMS10.hca.corpad.net>

According to this blogger (and I have no reason to doubt it really) the RunQueue length as reported by sar includes *both* processes on CPU and processes waiting for CPU. http://shallahamer-orapub.blogspot.com/2010/07/os-cpu-run-queue-not-what-it-appears.html

(Particularly on Linux)

Can anyone confirm or deny? Based on my review of sar reports over 24 hours it appears to be the case but not 100% positive. (I'm basically just looking for confirmation before I file it away as fact)

(It appears after doing some more research that this is a very muddy issue: http://hoopercharles.wordpress.com/2010/06/14/cpu-run-queue-what-is-wrong-with-this-quote/ )

It appears that sar RunQueue includes both processes in memory and those waiting for CPU so that runqueue should be concerning only when RQ passes # of CPUs on host and is sustained for 'x' amount of time. (where X is defined by the admin). Is that basically correct?

Chris Taylor
Oracle DBA
Parallon IT&S

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Received on Thu Mar 07 2013 - 17:10:30 CET