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LinuxMall.com: Warning: SMP Scaling May Be Hazardous to Your OS Health

[ Thanks to LinuxNews.com for this link.
]

“During his presentation on scaling Linux to the enterprise,
BitMover, Inc. CEO Larry McVoy raised a few furrowed eyebrows at
the recently-held Colorado Linux Info Quest (CLIQ). His message:
Symetric multiprocessing (SMP) scaling may be hazardous to your
operating system (OS) health.”

“McVoy said that the level of harm is “directly proportional” to
the amount of scaling and is “worse than linear” in the number of
processors. Converting a uniprocessor OS to a four-way SMP OS
introduces a “small amount of damage.” Converting the four-way SMP
OS to a 32-way SMP OS does even more damage, he told the crowd.
McVoy calls this phenomenon “the locking cliff.””

“The bottom line, said McVoy, is that: “Linux needs to have
bragging rights on ‘big iron’ to be taken seriously in the
enterprise. But the traditional way of getting those rights
involves a series of changes which do a lot of damage to the source
base. So the problems are that Linux needs to scale, and
traditional scaling is a bad idea. Linux will use traditional
scaling if nothing else shows up,” he said, “but SMP clusters is a
better way to do it.
I’m the driving force behind that and I’m
not driving because I’m wrapped up in BitKeeper.””

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