Article View: comp.arch
Article #13036Re: Using a DMA chip in strange ways
From: mahar
Date: Thu, 19 Feb 1987 20:43
Date: Thu, 19 Feb 1987 20:43
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1353 bytes
In article <4343@columbia.UUCP>, dupuy@amsterdam.columbia.edu (Alexander Dupuy) writes:
> Since the DMA chip on your favorite disk/tape controller works by stealing
> bus cycles when the CPU is busy with other things (like arithmetic), would
> there be any advantage in having a DMA chip which would simply be used for
> memory to memory copies (from user to kernel space, or from one user space to
> another)?
>
The memory management hardware could be used to send messages between the
OS and tasks if messages were multiples of the page size. This could reduce
message transfer time a lot.
--
Mike Mahar
UUCP: {turtlevax, cae780}!weitek!mahar
Disclaimer: The above opinions are, in fact, not opinions.
They are facts.
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!watmath!clyde!rutgers!ames!ucbcad!ucbvax!decvax!decwrl!sun!imagen!auspyr!sci!weitek!mahar From: mahar@weitek.UUCP Newsgroups: comp.arch Subject: Re: Using a DMA chip in strange ways Message-ID: <298@attila.weitek.UUCP> Date: Thu, 19-Feb-87 15:43:41 EST Article-I.D.: attila.298 Posted: Thu Feb 19 15:43:41 1987 Date-Received: Sun, 22-Feb-87 03:15:36 EST References: <4343@columbia.UUCP> Distribution: world Organization: WEITEK Corp. Sunnyvale, CA Lines: 18 Summary: use the memory management hardware to send messages