Re: AGP and PAT (induced?) problem (on AMD family 6)

From: Rene Herman
Date: Tue Aug 19 2008 - 15:21:30 EST


On 19-08-08 21:07, Venki Pallipadi wrote:

On Tue, Aug 19, 2008 at 07:19:44AM -0700, Rene Herman wrote:

I believe the 14 seconds for first shutdown to 5 later might be
telling. Sounds like something might have fixed up uncached
entries.

I'd really like a reply from the AGP or PAT side right about now.

Hmm. Looks like there are more than 16000 entries in the PAT list!

This delay may be due to the overhead of parsing this linked list
everytime for a new entry, rather than any problem with cache setting
itself.

I am working on a patch to optimize this pat list parsing for the
simple case. Should be able to send it out later today, for testing.

Thanks for the reply. It's with 64MB of AGP memory which I guess is at the low end these days. Would your reply mean that basically everyone on 2.6.27 should now be experiencing this?

I noticed it was PAT related due to Shaohua Li's:

http://marc.info/?l=linux-kernel&m=121783222306075&w=2

which lists very different times (patch there did not help any).

As another by the way, probably not surprising but I earlier also tried both unmounting and completely compiling out debugfs just in case I was seeing a debugging related sysmptom. No help either.

It's evening here so I'll probably not be able to test until tomorrow.

Rene.
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