Skip site navigation (1)Skip section navigation (2)
Date:      Wed, 6 Aug 2003 10:05:17 -0700
From:      David Schultz <das@freebsd.org>
To:        Jan Grant <Jan.Grant@bristol.ac.uk>
Cc:        Roderick van Domburg <r.s.a.vandomburg@student.utwente.nl>
Subject:   Re: Tuning HZ for semi-realtime applications
Message-ID:  <20030806170517.GA6961@HAL9000.homeunix.com>
In-Reply-To: <Pine.GSO.4.44.0308061133330.15854-100000@mail.ilrt.bris.ac.uk>
References:  <20030806044351.GA3881@HAL9000.homeunix.com> <Pine.GSO.4.44.0308061133330.15854-100000@mail.ilrt.bris.ac.uk>

next in thread | previous in thread | raw e-mail | index | archive | help
On Wed, Aug 06, 2003, Jan Grant wrote:
> On Tue, 5 Aug 2003, David Schultz wrote:
> 
> >   100 Hz works just fine for
> > interactive jobs; humans can't tell the difference.[1]
> 
> They can if they're using X :-) I gave Denim* a trial recently; it was
> unusable at 100Hz and fine at 1000.

Yes, polling a tablet device is an interesting case where it
matters.  If you reread my last message carefully, you'll noticed
that I suggested bumping up the default HZ a bit, since the
overhead appears to be well into the noise even at 500 Hz.
An alternative would be to implement a high-resolution timer
facility similar to the Solaris cyclics implementation.



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030806170517.GA6961>