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Date: Wed, 13 Jan 2016 11:02:35 -0800
From: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
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To: Will Deacon <will.deacon@arm.com>
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Subject: Re: [v3,11/41] mips: reuse asm-generic/barrier.h
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On 01/13/2016 02:45 AM, Will Deacon wrote:
> On Tue, Jan 12, 2016 at 12:45:14PM -0800, Leonid Yegoshin wrote:
>>
> I don't think the address dependency is enough on its own. By that
> reasoning, the following variant (WRC+addr+addr) would work too:
>
>
> P0:
> Wx = 1
>
> P1:
> Rx == 1
> <address dep>
> Wy = 1
>
> P2:
> Ry == 1
> <address dep>
> Rx = 0
>
>
> So are you saying that this is also forbidden?
> Imagine that P0 and P1 are two threads that share a store buffer. What
> then?
>

I ask HW team about it but I have a question - has it any relationship 
with replacing MIPS SYNC with lightweight SYNCs (SYNC_WMB etc)? You use 
any barrier or do not use it and I just voice an intention to use a more 
efficient instruction instead of bold hummer (SYNC instruction). If you 
don't use any barrier here then it is a different issue.

May be it has sense to return back to original issue?

- Leonid