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

From: Alexander Duyck
Date: Tue Nov 18 2014 - 10:45:45 EST

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:

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?


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.


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