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From: Alexander Duyck <alexander.h.duyck@redhat.com>
To: David Laight <David.Laight@ACULAB.COM>,
	"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
	"netdev@vger.kernel.org" <netdev@vger.kernel.org>,
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	"torvalds@li
Subject: Re: [PATCH 0/4] Add lightweight memory barriers fast_rmb() and fast_wmb()
Date: Tue, 18 Nov 2014 07:44:13 -0800	[thread overview]
Message-ID: <546B694D.3080604@redhat.com> (raw)
In-Reply-To: <063D6719AE5E284EB5DD2968C1650D6D1C9F2930@AcuExch.aculab.com>


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

      reply	other threads:[~2014-11-18 15:44 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-11-17 17:17 [PATCH 0/4] Add lightweight memory barriers fast_rmb() and fast_wmb() Alexander Duyck
2014-11-17 17:17 ` [PATCH 1/4] arch: Cleanup read_barrier_depends() and comments Alexander Duyck
2014-11-17 17:18 ` [PATCH 2/4] arch: Add lightweight memory barriers fast_rmb() and fast_wmb() Alexander Duyck
2014-11-17 20:04   ` Benjamin Herrenschmidt
2014-11-17 20:24     ` Alexander Duyck
2014-11-18  0:39       ` Benjamin Herrenschmidt
2014-11-18  3:13         ` Alexander Duyck
2014-11-18 11:58           ` Will Deacon
2014-11-18 16:20             ` Alexander Duyck
2014-11-18 16:48               ` Will Deacon
2014-11-18 21:07           ` Benjamin Herrenschmidt
2014-11-17 20:18   ` Paul E. McKenney
2014-11-17 21:11     ` Alexander Duyck
2014-11-17 23:17       ` Paul E. McKenney
2014-11-18  3:33         ` Alexander Duyck
2014-11-18  0:38     ` Benjamin Herrenschmidt
2014-11-17 20:52   ` Linus Torvalds
2014-11-17 21:54     ` Alexander Duyck
2014-11-18  0:43       ` Benjamin Herrenschmidt
2014-11-18  0:41     ` Benjamin Herrenschmidt
2014-11-17 17:18 ` [PATCH 3/4] r8169: Use fast_rmb() and fast_wmb() for DescOwn checks Alexander Duyck
2014-11-17 17:18 ` [PATCH 4/4] fm10k/igb/ixgbe: Use fast_rmb on Rx descriptor reads Alexander Duyck
2014-11-17 21:32   ` Jeff Kirsher
2014-11-18  9:57 ` [PATCH 0/4] Add lightweight memory barriers fast_rmb() and fast_wmb() David Laight
2014-11-18 15:44   ` Alexander Duyck [this message]

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