Date: Thu, 14 Jan 2016 00:57:58 +1100 (EST) From: Ian Smith <smithi@nimnet.asn.au> To: "darwinsurvivor@gmail.com" <darwinsurvivor@gmail.com> Cc: kpneal@pobox.com, "William A. Mahaffey III" <wam@hiwaay.net>, freebsd-questions@freebsd.org Subject: Re: Task to busy one CPU 100% for a period of time? Message-ID: <20160114000637.U93547@sola.nimnet.asn.au> In-Reply-To: <CAMuYtRDoKfGC0awAon1%2BBmUKsj6ugau-umgzCiR8MpbA37QTgQ@mail.gmail.com> References: <20160111002439.Q93547@sola.nimnet.asn.au> <56928802.2040802@hiwaay.net> <20160111154616.G93547@sola.nimnet.asn.au> <20160111203832.GC88498@neutralgood.org> <20160113052558.R93547@sola.nimnet.asn.au> <CAMuYtRDoKfGC0awAon1%2BBmUKsj6ugau-umgzCiR8MpbA37QTgQ@mail.gmail.com>
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On Tue, 12 Jan 2016 13:02:26 -0800, darwinsurvivor@gmail.com wrote:
> Have you looked at the sysutils/stress utility? It may do what you need.
>
>
> ~Doug
I have now, thanks :) It works well, given I've only tested the -c CPU
load option so far. If I'd found it sooner, I might not have bothered
compiling Kevin's little program and writing the below script to do
about the same thing with it .. but I'm grateful for the exercise!
> On Tue, Jan 12, 2016 at 10:36 AM, Ian Smith <smithi@nimnet.asn.au> wrote:
> > On Mon, 11 Jan 2016 15:38:32 -0500, kpneal@pobox.com wrote:
[..]
> > > cc -c main.c
> > > cc -c dummy.c
> > > cc -o load1 main.o dummy.o
> > >
> > > One invocation of this program should consume an entire CPU and therefore
> > > raise the load average by 1.00. Run as many as you like.
> > >
> > > (The reason for the two compilations is to avoid having any compiler
> > > optimize away the for loop. Just to be safe.)
> >
> > Thankyou Kevin. Works a treat, so far tested 8 at once, loadavg = 8.00
> >
> > I'll follow up hopefully tomorrow with results of a sh script to run a
> > given number of instances for a given time, needing a bit more testing.
So here; both this and stress give equivalent results with 2 to 8 tasks;
over 4 I'm running into overheating (~90C), acpi_thermal kicking in, CPU
slowing apparently - but it is summer, and still ~28C|82F at midnight!
#!/bin/sh
# 12/1/16 add2load.sh thanks Kevin Neal <kpneal@pobox.com> for load1 C code
me=`basename $0`
[ ! "$1" ] && echo "usage: $me tasks(1-12) [seconds (dflt 930)]" && exit 1
tasks=0; [ $1 -ge 1 -a $1 -le 12 ] && tasks=$1
[ $tasks -eq 0 ] && echo "$me tasks ($1) must be 1..12" && exit 1
[ "$2" ] && secs=$2 || secs=930 # default 15.5m
ok=''; [ $secs -ge 20 -a $secs -le 1800 ] && ok=y
[ ! "$ok" ] && echo "$me seconds ($secs) must be 20..1800" && exit 1
echo "`date` $me running $tasks load1 tasks for ${secs}s"
bgpids=''
done=0; trap "done=1; sleep=0" int quit term
while [ $done -eq 0 ]; do
while [ $tasks -gt 0 ]; do
~/bin/load1 &
bgpids="$bgpids $!"
tasks=$((tasks-1))
done
sleep $secs
done=1
done
kill $bgpids || echo "$me: error killing pids $bgpids"
echo "`date` $me done"
trap - int quit term
exit 0
cheers, Ian
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