Re: MMIO regions

["Stephen C. Tweedie" <sct@redhat.com>]

Hi,

On Mon, 4 Oct 1999 14:29:14 -0400 (EDT), James Simmons
<jsimmons@edgeglobal.com> said:

> Okay. But none of this prevents a rogue app from hosing your system. Such
> a process doesn't have to bother with locks or semaphores. 

And we talked about this before.  You _can_ make such a guarantee, but
it is hideously expensive especially on SMP.  You either protect the
memory or the CPU against access by the other app, and that requires
either scheduler or VM interrupts between CPUs.

--Stephen


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