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:
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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/