SCHED_ULE and loadavg() results

[Jeff Roberson]

On Mon, 2 Feb 2004, Melvyn Sopacua wrote:

> Hi,
>
> following up on recent statements regarding loadavg() calculation:
> I currently have a machine compiling a make release, using SCHED_ULE.
>
> I use WORLDARGS='-j4' and have observed the following:
> * During compilation loads gets up to 15 and stays there, but I feel this has
> been "set in motion" by top(1). The buildprocess already was an hour or 2 on
> it's way (set it up remotely) and the first time I ran top, the load was
> three. I quit top, and monitored slowly by calling uptime(1) about every
> minute manually (to avoid sleep()), but the load still went up.
> * changing top's refresh frequency to 5, had no impact whatsoever - load still
> goes up, finally changed it to 1 and kept monitoring.
> * during 'install' stage load went down to appr. 0.62 and kept lurking between
> 0.62 and 1.20, still with many make(10 and sh(1) processes, but no compilers.
> * during kernel build stage load went quickly up to 3 and 5, with less
> compilers this time.
> * it's now building ports and balancing between 1.10 and 3.50.
>
> I've used this machine more often lately to build dists, but never saw the
> load come above 6, using SCHED_4BSD. Last time was about 1,5 weeks ago.

We're tinkering with the load average reporting right now.  I assure you
that it is a problem with statistics and not a problem with the actual
machine load.  Thank you for the thorough report.  I'll send a follow-up
mail to current@ when we're doing tinkering with loadvg.

Cheers,
Jeff

>
> Kernel config and dmesg attached.
> Full command is:
> nohup make release BUILDNAME=5.2-idgnl-CURRENT \
> CHROOTDIR=/webdocs/scratch/CURRENT \
> CVSROOT=/home/ncvs DOC_LANG=en_US.ISO8859-1 -DMAKEISOS \
> RELEASEDIRFILES=/usr/ports/distfiles WORLD_FLAGS=-j4 \
> KERNELS='DBSERVER SERVER3' -DNOPORTREADMES &
>
> --
> Melvyn
>
> =======================================================
> FreeBSD sarevok.idg.nl 5.2-CURRENT FreeBSD 5.2-CURRENT #0: Wed Jan 28 18:01:18
> CET 2004
> root at sarevok.lan.webteckies.org:/usr/obj/usr/src/sys/SAREVOK_NOAPM_NODEBUG
> i386
> =======================================================
>