svn commit: r235931 - head/sys/powerpc/include
Marcel Moolenaar
marcel at xcllnt.net
Fri May 25 00:04:57 UTC 2012
On May 24, 2012, at 3:46 PM, Nathan Whitehorn wrote:
> On 05/24/12 17:22, Marcel Moolenaar wrote:
>>
>> 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
>>>>
>>>> This is absolutely not what I concluded from our discussions. I have no idea
>>>> how we could end up so out of sync...
>>>>
>>>
>>> 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,
>>
>
> I don't think it really makes a difference. Basically nothing uses wmb(), and those things that do mostly use it wrong and need sync. So it should probably stay as [lw]sync.
Works for me.
Thanks!
--
Marcel Moolenaar
marcel at xcllnt.net
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