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Date:      Mon, 24 Jan 2011 20:07:25 -0700
From:      Chad Perrin <perrin@apotheon.com>
To:        FreeBSD Questions <freebsd-questions@freebsd.org>
Subject:   Re: more CPU being used than I have (?)
Message-ID:  <20110125030725.GA62670@guilt.hydra>
In-Reply-To: <1295917366.59721.2.camel@main>
References:  <20110124235740.GA62134@guilt.hydra> <1295917366.59721.2.camel@main>

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On Tue, Jan 25, 2011 at 01:02:46AM +0000, Craig Butler wrote:
> On Mon, 2011-01-24 at 16:57 -0700, Chad Perrin wrote:
> > I'm running a two-core laptop that, once in a great while, shows
> > approximately 250% CPU usage by a single process in top.  How exactly
> > does that work?
> >=20
> > Note: It's not entirely surprising that this particular process is
> > consuming a lot of resources.  It's just surprising to me that it's
> > consuming more than CPUs * 100%.
>=20
> Hi Chad
>=20
> Its to do with top using weighted CPU percentage... for some reason this
> show peaks as more usage than 100% -- maybe something to do with the top
> averaging out over a specific time.
> I find that raw CPU mode gives a more accurate representation.=20
>=20
> raw mode is toggled by passing the -C argument to top.

Do you have a reference to a relatively simple explanation of how that
weighting works (and why)?

--=20
Chad Perrin [ original content licensed OWL: http://owl.apotheon.org ]

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