Date: Mon, 12 Jun 2006 07:21:04 -0700 (PDT) From: Danial Thom <danial_thom@yahoo.com> To: freebsd-performance@freebsd.org Subject: Initial 6.1 questions Message-ID: <20060612142104.188.qmail@web33301.mail.mud.yahoo.com>
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I'm just setting up to evaluate 6.1 for a project, and before I tune I hoped to get some feedback on why some things are the way they are. first, why is the default for HZ now 1000? It seems that 900 extra clock interrupts aren't a performance enhancement. Is there a reason that ITR isn't a tunable in the em driver? It seems more usable generally to end users than the delays. Running a simple test with a traffic generator (firing udp packets to a blackhole), the system overhead with a single processor goes up from 10% to 15% when running a kernel with SMP enabled (and nothing else different). I have ITR set to 6000 interrupts per second. That seems like an awful lot of overhead. Is there some problem running an SMP-enabled kernel when only 1 processor is present, or is there really 50% extra overhead on an SMP scheduler? I'll have a dual core in a few days to test with. Lastly, is there a utility similar to cpustat in DragonflyBSD which shows the per-cpu usage stats? Thanks, DT __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
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