Re: chasing the four level page table

[Dave Jones <davej@redhat.com>]

On Thu, Jan 06, 2005 at 03:05:49PM -0500, Jon Smirl wrote:
 > On 6 Jan 2005 20:38:27 +0100, Andi Kleen <ak@muc.de> wrote:
 > > You can't use get_user_pages in this case because the AGP aperture
 > > can be above mem_map.  If none of the callers take page_table_lock
 > > already you would need to add that too. I guess from the context the lock
 > > is not taken, but better double check.
 > > 
 > > Perhaps we should add a get_user_phys() or somesuch for this.
 > 
 > No where in DRM is page_table_lock being taken.  Also, no other device
 > driver takes page_table_lock either, so that probably implies that DRM
 > shouldn't start doing it to. 

No other device driver is also doing such lowlevel stuff with
page tables directly afaics. drivers/char/drm seem to be the only drivers
using [pgd|pmd|pte]_offset() routines.

		Dave