Re: Scaling noise

Larry McVoy
2003-09-04T02:47:47Z

On Thu, Sep 04, 2003 at 04:21:16AM +0200, Daniel Phillips wrote:
> On Thursday 04 September 2003 02:49, Larry McVoy wrote:
> > It's much better to have a bunch of OS's and pull
> > them together than have one and try and pry it apart.
>
> This is bogus. The numbers clearly don't work if the ccCluster is made of
> uniprocessors, so obviously the SMP locking has to be implemented anyway, to
> get each node up to the size just below the supposed knee in the scaling
> curve. This eliminates the argument about saving complexity and/or work.

If you thought before you spoke you'd realize how wrong you are. How many
locks are there in the IRIX/Solaris/Linux I/O path? How many are needed for
2-4 way scaling?

Here's the litmus test: list all the locks in the kernel and the locking
hierarchy. If you, a self claimed genius, can't do it, how can the rest
of us mortals possibly do it? Quick. You have 30 seconds, I want a list.
A complete list with the locking hierarchy, no silly awk scripts. You have
to show which locks can deadlock, from memory.

No list? Cool, you just proved my point.
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Larry McVoy lm at bitmover.com http://www.bitmover.com/lm