Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!hplabs!hpfcso!hpfcdc!mckee
From: mckee@hpfcdc.HP.COM (Bret McKee)
Newsgroups: comp.os.minix
Subject: Re: ST MINIX 1.1 Performance bug
Message-ID: <6780003@hpfcdc.HP.COM>
Date: 20 Mar 90 15:12:17 GMT
References: <1081@bnrgate.bnr.ca>
Organization: HP Ft. Collins, Co.
Lines: 38

>Using ST MINIX 1.1, I began the process of upgrading from the net postings.
>Once I had all the original 1.5.0 postings on my HD, I figured this MINIX
>sutff is multi-tasking, right?  All the postings were on my disk as: 00,
>01, 02, ..., 73.  So I started typing in the following commands (I know,
>I could use a shell script):
>
>    uudecode 01 &
>    uudecode 02 &
>    uudecode 03 &
>    uudecode 04 &
>  etc.
>
>Then things started to get REAL SLOW.  Before anyone jumps to conclusions
>about "Yeah, but you're running all those processes...", here's something
>to ponder...
>Using the "ps" hot-key (Alt/Ctrl/F1), I noticed that usually one or two of 
>these processes were using inordinate amounts of CPU time.  During the 
>01-73 posting uudecodes, I found that all will eventually go to completion.
>Once one of these processes is in this state (it may be the ONLY process
>still running), it does I/O at the rate of about 1 per 8-10 seconds.  Also,
>the CPU times which are usually in the low three-digit numbers climb to
>16000+!!! units in the "sys" column.

On the PC 1.1, there is a problem with the CPU accounting.  It does not
handle lots of things correctly.  Also, the single threaded filesystem and
device drivers will really kill you running those uudecodes...

Bret

---
Bret Mckee

Hewlett Packard 
HP-UX Development Lab
Phone:(303)229-6116	email: mckee@hpmckee or mckee%hpmckee@hplabs.hp.com
Copyright (c) Bret Mckee 1990.  All Rights Reserved.
 
Of course, these are just my opinions...