[ Thanks to LinuxDevices.com for this link.
]
“MontaVista Software has taken the wraps off what it calls a
“hard real-time fully preemptable Linux kernel prototype,” based on
Linux kernel 2.4. The company claims its kernel modification has
the power to revolutionize the application responsiveness of Linux,
while fully preserving the Linux programming model. The
prototype kernel modification is currently showing better than a
10-fold improvement in worst-case kernel responsiveness, but is
expected to reach gains of 100-fold or better, by the time the
technology is incorporated into MontaVista’s Hard Hat Linux
distribution in the January 2001 timeframe.”
“Kevin Morgan, MontaVista’s Vice President of Engineering, says
“the kernel modification results in a “relatively fully preemptable
kernel at this point in time. The long locks that are held in a SMP
environment are being implemented as a no-preempt region, which we
feel is a good starting point for this approach. Our goal is to
eventually get those to much shorter periods. We’ve got a lot of
measuring work and tuning work to do, as well as refinement of the
specific techniques to both drive the responsiveness to even better
numbers and to improve some of the architectural attributes. Right
now what we’re putting out is a prototype, in the best spirit of
‘release early, release often’.”
“Morgan points out that the enhanced kernel responsiveness is
not merely useful for esoteric real-time industrial process control
systems, but rather is of value even to today’s desktop PC users.
“This technology has use in all segments of the market, including
the desktop, for the simple reason that desktops these days require
multi-programming and multi-processing, with live streaming media
in action,” says Morgan. “For example, as a desktop user I want to
be able to watch a movie and hear the sound, while also running a
browser and my mail program. And when I use the mail program and
the browser, I don’t want any glitches in the movie or sound. That
really requires improvements in Linux responsiveness, and that kind
of behavior really is a real-time problem, because a human is
really pretty good at detecting glitches in continuous real-time
operation. So, this technology is applicable on the desktop. And,
of course, it’s highly applicable in the more traditional embedded
control environments.”