Subject: Re: Even more info on my memory problem...
To: None <chopps@emunix.emich.edu>
From: Niklas Hallqvist <niklas@appli.se>
List: amiga-dev
Date: 03/11/1994 12:44:36
>>>>> "Chris" == Chris Hopps <chopps@emunix.emich.edu> writes:

Chris> I guess I donn't understand? If the data access caused a page
Chris> fault and was odd aligned it must be on a page boundry.  Maybe
Chris> you could give a few examples (with faked addresses) to make it
Chris> clearer.

suppose a0 contains $6000, which is paged out.

bftst a0@(1){#0:#24} accesses at $6001 but is still on the same
page that $6002 and $6003

This causes a pagefault and succeeds normally.  However if the
next instruction (and the page does not get paged out immediately)
is:

movel a0@,d0

d0 will have the high word ($6000-$6001) mutated, with no correlation
whatsoever to what's in $6000.  The word can often be found in part
of another stochastic register, thus leading me to think that the
words been recently fetched and left erroneously in some cache
on the card (the in-CPU cache isn't the problem, I've tried both
with and without it).

Weird, hah...

Niklas



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