Date: Mon, 28 Mar 2011 23:18:18 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Luke Kenneth Casson Leighton <luke.leighton@gmail.com>
Cc: paulmck@linux.vnet.ibm.com, Will Newton <will.newton@gmail.com>,
        linux-kernel@vger.kernel.org
Subject: Re: advice sought: practicality of SMP cache coherency implemented
 in assembler (and a hardware detect line)
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>  ok - well, having thought about this a little bit (in a non-detailed
> high-level way) i was sort-of hoping, as alan hinted at, to still do
> SMP, even if it's slow, for userspace.   the primary thing to prevent
> from happening is to have kernelspace data structures from
> conflicting.
> 
>  i found kerrigan, btw, spoke to the people on it: louis agreed that
> the whole idea was mad as hell and was therefore actually very
> interesting to attempt :)
> 
>  as a first approximation i'm absolutely happy for existing pthreads
> applications to be forced to run on the same core.

The underlying problem across a cluster of nodes can be handled
transparently. MOSIX solved that problem a very long time ago using DSM
(distributed shared memory). It's not pretty, it requires a lot of tuning
to make it fly but they did it over comparatively slow interconnects.

Alan
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