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

Alexander Duyck
2014-11-18T15:44:13Z

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