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Date: Tue, 30 Sep 2008 14:36:51 -0700
From: Peter Grehan <grehan@freebsd.org>
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Cc: freebsd-ppc@freebsd.org
Subject: Re: 64-bit atomic ops on 32-bit CPU -- was: ZFS .. on PowerPC ?
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Hi Matt,

> Isn't there some kind of semaphore primitive in FreeBSD that can be
> used?

  The issue is the OpenSolaris ZFS code that makes liberal use of calls 
such as atomic_add_64(&ptr_to_uint64). This is emulated by having a 
global lock for all 64-bit atomic operations, but it would be better if 
this could be done without such workarounds on 32-bit ppc.

later,

Peter.