Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!mcvax!hp4nl!philapd!ssp1!roelof
From: roelof@idca.tds.PHILIPS.nl (R. Vuurboom)
Newsgroups: comp.arch
Subject: Re: Caches
Summary: Terminology cache clash
Message-ID: <143@ssp1.idca.tds.philips.nl>
Date: 29 Jun 89 12:46:36 GMT
References: <799@acorn.co.uk> <95@altos86.Altos.COM> <195@dg.dg.com> <12070@pur-ee.UUCP>
Organization: Philips Telecommunication and Data Systems, The Netherlands
Lines: 28

In article <12070@pur-ee.UUCP> hankd@pur-ee.UUCP (Hank Dietz) writes:

>Hmmm.  It seems to me that there are at least three, not two, alternatives:
>write-through, write-back, and lazy-write.  Using the lazy-write idea, you
>have the cache watch for free memory bus cycles and execute a "pending"
>entry write whenever it finds a free cycle...  of course, if there are lots

The idea sounds good. I'm just wondering about the terminology.
A lazy-operation (scheme) is generally defined as a scheme where a particular
operation is carried out only when it can be delayed no longer.

In other words, it sounds like the general definition of what lazy-write 
would be describes exactly what the current definition of what write-back is.
What you describe with lazy-write sounds something like a "background-write".

Adding to the semantic confusion is of course the observation that in
order to write through to memory one has to write back to memory :-).

If we all could start over again we might have had:

- write through (was write through)
- lazy write (was write back)
- background write (was lazy write)

Am I write or am I wrong? :-) (Sorry, couldn't resist)
-- 
Roelof Vuurboom  SSP/V3   Philips TDS Apeldoorn, The Netherlands   +31 55 432226
domain: roelof@idca.tds.philips.nl             uucp:  ...!mcvax!philapd!roelof