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Date:      Thu, 24 May 2012 15:22:09 -0700
From:      Marcel Moolenaar <marcel@xcllnt.net>
To:        Nathan Whitehorn <nwhitehorn@freebsd.org>
Cc:        svn-src-head@freebsd.org, svn-src-all@freebsd.org, Marcel Moolenaar <marcel@freebsd.org>, src-committers@freebsd.org
Subject:   Re: svn commit: r235931 - head/sys/powerpc/include
Message-ID:  <358A54BA-6B8E-4685-8CDD-CCAC305ACA2B@xcllnt.net>
In-Reply-To: <4FBEB2F3.4060405@freebsd.org>
References:  <201205242045.q4OKjipb059398@svn.freebsd.org> <4FBEA493.4020702@freebsd.org> <EEFFC9C4-7469-4D70-A5C6-7F5CB19CAC28@xcllnt.net> <4FBEB2F3.4060405@freebsd.org>

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On May 24, 2012, at 3:15 PM, Nathan Whitehorn wrote:

>>> Summary:
>>> 1. *mb() must be lwsync or sync on all machines, except for wmb() =
which could be eieio
>>> 2. __ATOMIC_ACQ() must be isync (though could be reduced to lwsync =
with bus_space changes)
>>> 3. __ATOMIC_REL() must be lwsync or sync
>>=20
>> This is absolutely not what I concluded from our discussions. I have =
no idea
>> how we could end up so out of sync...
>>=20
>=20
> Thanks for the quick change. No idea how we got out of sync. I find =
all of this synchronization stuff a little mind-bending, so sorry for =
any miscommunication. __ATOMIC_ACQ() needed to also be isync on ppc64, =
so I've fixed that up. Things should be good now.

Ok. I didn't change wmb() to eieio as I wanted to avoid a pendulum =
effect.
I'll reread our emails and make sure wmb() is what we think it is and if
so I'll do a followup commit.
FYI,

--=20
Marcel Moolenaar
marcel@xcllnt.net





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