[dm-devel] [patch 4/4] dm-writecache: use new API for flushing

[Mikulas Patocka]

On Wed, 30 May 2018, Dan Williams wrote:

> > Great find! Thanks for the due diligence. Feel free to add:
> >
> >     Acked-by: Dan Williams <dan.j.williams at intel.com>
> >
> > ...on the reworks to unify ARM and x86.
> 
> One more note. The side effect of not using dax_flush() is that you
> may end up flushing caches on systems where the platform has asserted
> it will take responsibility for flushing caches at power loss. If /
> when those systems become more prevalent we may want to think of a way
> to combine the non-temporal optimization and the cache-flush-bypass
> optimizations. However that is something that can wait for a later
> change beyond 4.18.

We could define memcpy_flushpmem, that falls back to memcpy or 
memcpy_flushcache, depending on whether the platform flushes the caches at 
power loss or not.

Mikulas