netdev - Re: [PATCH 0/4] Add lightweight memory barriers fast_rmb() and fast

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Date:	Tue, 18 Nov 2014 07:44:13 -0800
From:	Alexander Duyck <alexander.h.duyck@...hat.com>
To:	David Laight <David.Laight@...LAB.COM>,
	"linux-arch@...r.kernel.org" <linux-arch@...r.kernel.org>,
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Subject: Re: [PATCH 0/4] Add lightweight memory barriers fast_rmb() and fast_wmb()


On 11/18/2014 01:57 AM, David Laight wrote:
> From: Alexander Duyck
>> These patches introduce two new primitives for synchronizing cache-enabled
>> memory writes and reads.  These two new primitives are:
>>
>> 	fast_rmb()
>> 	fast_wmb()
> Not sure I like the names.
> If the aim is to sync data into the local cache so that hardware
> that is doing cache-snooping accesses sees the data then maybe
> 	local_rmb() and local_wmb()

Yeah, that is the general consensus.  I am planning to change them to 
coherent_rmb() and coherent_wmb().

> IIRC read_barrier_depends() is a nop on everything except alpha.
> Maybe add the default if it isn't defined by the MD file?
>
> 	David
>   

 From my patch the only two I saw define it were alpha and blackfin. It 
is already defined in asm-generic, the rest is just clean-up since I 
suspect some of the arch tree barrier.h calls just borrowed from 
asm-generic without sorting out what became redundancies.

Thanks,

Alex
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