Subject: Re: "pmap_unwire: wiring ... didn't change!"
To: Chuck Silvers <firstname.lastname@example.org>
From: Markus W Kilbinger <email@example.com>
Date: 02/15/2005 23:33:40
>>>>> "Chuck" == Chuck Silvers <firstname.lastname@example.org> writes:
>> Maybe I should send-pr now (more precisely)?
Chuck> please, that would be great.
Chuck> ok, so it's clear the corruption can happen when reading
Chuck> from disk. can you tell if the file is ever corrupted while
Chuck> being written to disk? you'll need to use a pattern
Chuck> generator to create some files (rather than reading them
Chuck> from disk). ideally you'd check the data by reading it on
Chuck> some other platform that doesn't have this bug, but I'd
Chuck> think that if all of the data can be read back correctly on
Chuck> the qube at least part of the time, then it's likely that
Chuck> the corruption is only on the read side.
As described in the pr I wrote a (simple) pattern generator: The
corruptions occur mostly during writing (have a look at the pr if you
are interested in the corruption pattern). Reading seems to corrupt
data only when accessing 2 files simultaneously (as 'cmp' does), but
in general not that much as writing.
BTW: I did _not_ explant my qube2's harddisk for data comparison in
another machine. I've just rebooted the machine multiple times and
repeated the comparison: All the constant diff's are blamed to be
writing related. I hope that's sufficient...
Chuck> FYI, I'm probably not going to have time to pursue this
Chuck> cache problem soon, so hopefully one of the other MIPS guys
Chuck> can run with it.