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Date: Sun, 19 Aug 2007 22:44:38 +1000 (EST)
From: Bruce Evans <brde@optusnet.com.au>
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To: Jeff Roberson <jroberson@chesapeake.net>
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Cc: Pawel Jakub Dawidek <pjd@freebsd.org>, freebsd-arch@freebsd.org
Subject: Re: Lockless uidinfo.
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On Sun, 19 Aug 2007, Jeff Roberson wrote:

> On Sun, 19 Aug 2007, Bruce Evans wrote:

>> atomic_*long() shouldn't exist (and doesn't exist in my version) since
>> longs should actually be long (twice as long as registers) and thus
>> especially epensive to lock.
>
> Well unfortunately this is not how the compiler implements them on the 
> architectures that we support.  So in this case long is 32bit on 32bit 
> machines and 64bit on 64bit machines and as such requires each architecture 
> to treat them specially.  I don't think it's unreasonable to add an 
> atomic_fetchadd_long() that conforms to the definition of long that is 
> actually in use.

The compiler has nothing to do with this.  The implementation is FreeBSD's
and it is poor, like I said.

[Context lost to top posting]

Bruce