From owner-freebsd-hackers Tue Apr 30 13:33:26 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id NAA04667 for hackers-outgoing; Tue, 30 Apr 1996 13:33:26 -0700 (PDT) Received: from labinfo.iet.unipi.it (labinfo.iet.unipi.it [131.114.9.5]) by freefall.freebsd.org (8.7.3/8.7.3) with SMTP id NAA04628 Tue, 30 Apr 1996 13:32:58 -0700 (PDT) Received: from localhost (luigi@localhost) by labinfo.iet.unipi.it (8.6.5/8.6.5) id WAA07626; Tue, 30 Apr 1996 22:18:03 +0200 From: Luigi Rizzo Message-Id: <199604302018.WAA07626@labinfo.iet.unipi.it> Subject: Re: lmbench IDE anomaly To: rgrimes@GndRsh.aac.dev.com (Rodney W. Grimes) Date: Tue, 30 Apr 1996 22:18:02 +0200 (MET DST) Cc: koshy@india.hp.com, hackers@freebsd.org, current@freebsd.org In-Reply-To: <199604301634.JAA13493@GndRsh.aac.dev.com> from "Rodney W. Grimes" at Apr 30, 96 09:34:02 am X-Mailer: ELM [version 2.4 PL23] Content-Type: text Sender: owner-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk [about two concurrent benchmarks on one disk, and a 4x throughput degradation on IDE] > > Is this to be expected, or am i doing something wrong here? The system was > > otherwise idle during these tests. > > run those command with a ``time'' in front of them as in: > time lmdd if=/dev/rwd0a of=internal bs=1024 count=8192 # IDE disk > > You may be seeing CPU saturation effecting the ability of the system to It would be interesting to check if it is CPU saturation, or it is a bad interaction with disksort as someone suggested. I really don't know what to say because the total overhead due to rep insw is proportional to the total throughput, so it should be reduced. Luigi ==================================================================== Luigi Rizzo Dip. di Ingegneria dell'Informazione email: luigi@iet.unipi.it Universita' di Pisa tel: +39-50-568533 via Diotisalvi 2, 56126 PISA (Italy) fax: +39-50-568522 http://www.iet.unipi.it/~luigi/ ====================================================================