On Wed, Jan 05, 2011 at 03:28:53PM -0800, Linus Torvalds wrote:

On Wed, Jan 5, 2011 at 3:06 PM, Trond Myklebust
[off-list ref] wrote:

quoted

Yes. The fix I sent out was a call to invalidate_kernel_vmap_range(),
which takes care of invalidating the cache prior to a virtual address
read.

My question was specifically about the write through the regular kernel
mapping: according to Russell and my reading of the cachetlb.txt
documentation, flush_dcache_page() is only guaranteed to have an effect
on page cache pages.

I don't think that should ever matter. It's not like the hardware can
know whether it's a dcache page or not.

And if the sw implementation cares, it's doing something really odd.