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Date:      12 Jun 1999 14:22:42 -0700
From:      Arun Sharma <adsharma@home.com>
To:        Alfred Perlstein <bright@rush.net>
Cc:        smp@FreeBSD.ORG
Subject:   Re: simple_lock() ?
Message-ID:  <m3u2sddsgt.fsf@c62443-a.frmt1.sfba.home.com>
In-Reply-To: Alfred Perlstein's message of "Sat, 12 Jun 1999 15:09:16 -0500 (EST)"
References:  <Pine.BSF.3.96.990612150817.14320W-100000@cygnus.rush.net>

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Alfred Perlstein <bright@rush.net> writes:

> On 12 Jun 1999, Arun Sharma wrote:
> 
> > Alfred Perlstein <bright@rush.net> writes:
> > 
> > > The simple_lock/unlock/try_lock stuff looks like precursor work towards
> > > finer grained SMP.  Is this true?  right now it looks like it amounts
> > > to a NOP in SMP and UP systems, is this also true?
> > 
> > It is a nop in UP systems, but calls some locking primitive on a SMP
> > system. 
> 
> because of the BGL i don't see why his is nessesary...
> 
> confused, 

Here's a guess: the comments in simplelock.s indicate that the locking
code came from 4.4BSD lite2. But you're right - in a giant locked
kernel, they are wasteful.

	-Arun


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