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Date: Tue, 25 Aug 1998 10:41:07 -0400 (EDT)
From: Garrett Wollman <wollman@khavrinen.lcs.mit.edu>
Message-Id: <199808251441.KAA02038@khavrinen.lcs.mit.edu>
To: Doug Rabson <dfr@nlsystems.com>
Cc: "John S. Dyson" <dyson@iquest.net>, current@FreeBSD.ORG
Subject: Re: Serious bug in vm_page.h in current
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<<On Tue, 25 Aug 1998 10:11:36 +0100 (BST), Doug Rabson <dfr@nlsystems.com> said:

> On Tue, 25 Aug 1998, John S. Dyson wrote:

>> PAGE_BWAKEUP would decr busy, and wakeup if PG_WANTED
>> and busy == 0.
>> 
>> PAGE_WAKEUP would clear PG_BUSY, and wakeup if PG_WANTED.
>> 
>> Each of the above would ignore the other condition.  There will
>> be extra wakeups, but those won't significantly affect performance.

> I don't understand this part of the code of the code very well.  It
> doesn't seem to me that a few extra wakeups is a problem.  Not waking up
> at all is a problem...

This sounds very much like it could be related to the lockup Matt
Dillon and I have been seeing.  I just rebooted newsswitch with this
change in it; I should know by the end of the day whether it had
any effect.

-GAWollman

--
Garrett A. Wollman   | O Siem / We are all family / O Siem / We're all the same
wollman@lcs.mit.edu  | O Siem / The fires of freedom 
Opinions not those of| Dance in the burning flame
MIT, LCS, CRS, or NSA|                     - Susan Aglukark and Chad Irschick

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