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From: Robert Watson <rwatson@FreeBSD.org>
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To: Jeff Roberson <jroberson@chesapeake.net>
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Cc: Daniel Eischen <deischen@freebsd.org>, arch@freebsd.org,
	Alfred Perlstein <alfred@freebsd.org>,
	David Xu <davidxu@freebsd.org>, freebsd-arch@freebsd.org
Subject: Re: Getting rid of the static msleep priority boost
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On Wed, 19 Mar 2008, Jeff Roberson wrote:

>> Perhaps there are no performance differences, but the cv/mutex primitives 
>> are a nice clean interface that most everyone understands.  If you are 
>> going to write a professional OS from the ground up, I doubt you are going 
>> to have anything as convoluted as msleep() as part of your kernel API/ABI.
>
> One real obstacle to converting all locations to cv_* is the lack of support 
> for anything other than mtx def mutexes in the cv api.  It also just doesn't 
> seem like a good use of developer resources regardless of how you feel about 
> msleep.

I thought condvar was converted in 7.x to accepting a struct lock for 
precisely this reason?  I assume (perhaps incorrectly) that it can't be used 
with spin mutexes, but thought, as a result, that we could now use it with 
other lock types, such as sx locks?

Robert N M Watson
Computer Laboratory
University of Cambridge