[PATCH] unpaged: COW on VM_UNPAGED
authorHugh Dickins <hugh@veritas.com>
Tue, 22 Nov 2005 05:32:17 +0000 (21:32 -0800)
committerLinus Torvalds <torvalds@g5.osdl.org>
Tue, 22 Nov 2005 17:13:42 +0000 (09:13 -0800)
commit920fc356f58d0e455bdfa53451f1c58eb211a846
treecb5fe90bc74ad9dd95191bb3c105aadd833197f2
parent101d2be7646b7dd1c367d50208a59b29fce61398
[PATCH] unpaged: COW on VM_UNPAGED

Remove the BUG_ON(vma->vm_flags & VM_UNPAGED) from do_wp_page, and let it do
Copy-On-Write without touching the VM_UNPAGED's page counts - but this is
incomplete, because the anonymous page it inserts will itself need to be
handled, here and in other functions - next patch.

We still don't copy the page if the pfn is invalid, because the
copy_user_highpage interface does not allow it.  But that's not been a problem
in the past: can be added in later if the need arises.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
mm/memory.c