Re: [PATCH md 010 of 14] Convert various kmap calls to kmap_atomic

On Thursday December 1, akpm@osdl.org wrote:

NeilBrown [off-list ref] wrote:

quoted

+				paddr = kmap_atomic(page, KM_USER0);
 +				memset(paddr + offset, 0xff,
  				       PAGE_SIZE - offset);

This page which is being altered is a user-visible one, no?  A pagecache
page?

It can be, but also may not be..

We must always run flush_dcache_page() against a page when the kernel
modifies a user-visible page's contents.  Otherwise, on some architectures,
the modification won't be visible at the different virtual address.

Ok, I'll add that at an appropriate place, thanks.

NeilBrown