Date: Wed, 1 May 1996 22:17:32 +0200 (MET DST) From: J Wunsch <j@uriah.heep.sax.de> To: freebsd-hackers@freebsd.org (FreeBSD hackers) Subject: Re: lmbench IDE anomaly Message-ID: <199605012017.WAA10967@uriah.heep.sax.de> In-Reply-To: <199605010947.LAA08814@labinfo.iet.unipi.it> from Luigi Rizzo at "May 1, 96 11:47:43 am"
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As Luigi Rizzo wrote: > The original poster was doing a couple of lmdd from /dev/rwd0a, the raw > device. Does disksort get in the way in this case ? disksort() is always called, though Bruce pointed out that it's a nop in recent systems. > BTW, running a number of dd on /dev/wd0a works *much* better, you get > almost n times the bandwidth at least with up to 5 instances, what I > tried. You're measuring your buffer cache. Better use random() instead, it will be more accurate. ;-) -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)
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