[dm-devel] [PATCH] vmalloc: introduce vmap_pfn for persistent memory

[Christoph Hellwig]

On Wed, Nov 08, 2017 at 07:33:09AM -0500, Mikulas Patocka wrote:
> We could use the function clwb() (or arch-independent wrapper dax_flush()) 
> - that uses the clflushopt instruction on Broadwell or clwb on Skylake - 
> but it is very slow, write performance on Broadwell is only 350MB/s.
> 
> So in practice I use the movnti instruction that bypasses cache. The 
> write-combining buffer is flushed with sfence.

And what do you do for an architecture with virtuall indexed caches?