Date: Mon, 17 Aug 1998 18:12:00 +0000 (GMT) From: Terry Lambert <tlambert@primenet.com> To: Lars.Koeller@post.uni-bielefeld.de (Lars =?iso-8859-1?Q?K=F6ller?=) Cc: chuckr@glue.umd.edu, freebsd-smp@FreeBSD.ORG Subject: Re: Per processor load? Message-ID: <199808171812.LAA06500@usr08.primenet.com> In-Reply-To: <199808170550.FAA27256@mitch.hrz.uni-bielefeld.de> from "Lars =?iso-8859-1?Q?K=F6ller?=" at Aug 17, 98 07:50:28 am
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> But thats only the first part of the problem! Where can I get > processor specific load information? I need to draw a separate load > graph for each CPU?? System load is based on number of processees in the ready-to-run state. For a symmetric system, if the load is 1.0 or above, both CPU's should be actively working. I suppose that what you are asking for is a "processor not idle in the case of 1.0 >= load >= 0.0". To get this, you would have to insert counters into the per CPU idle loops, probably using the Appendix H cycle counter before and after the per CPU HLT instruction, subtracting the count at exit of the last HLT from both, and then subtracting the entry from the exit, and dividing to get an "idle ratio". Gathering this type of statistic could be actively harmful to CPU latency coming out of the HLT condition, and could be as high as 10% to 20% of the systems ability to do work. Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message
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