linux.git/mm/memory.c, branch v2.6.15

Make sure we copy pages inserted with "vm_insert_page()" on fork

2005-12-16T18:21:23+00:00

The logic that decides that a fork() might be able to avoid copying a VM
area when it can be re-created by page faults didn't know about the new
vm_insert_page() case.

Also make some things a bit more anal wrt VM_PFNMAP.

Pointed out by Hugh Dickins 

Signed-off-by: Linus Torvalds

get_user_pages: don't try to follow PFNMAP pages

2005-12-13T00:24:33+00:00

Nick Piggin points out that a few drivers play games with VM_IO (why?
who knows..) and thus a pfn-remapped area may not have that bit set even
if remap_pfn_range() set it originally.

So make it explicit in get_user_pages() that we don't follow VM_PFNMAP
pages, since pretty much by definition they do not have a "struct page"
associated with them.

Signed-off-by: Linus Torvalds

Allow arbitrary read-only shared pfn-remapping too

2005-12-12T04:38:17+00:00

The VM layer (for historical reasons) turns a read-only shared mmap into
a private-like mapping with the VM_MAYWRITE bit clear.  Thus checking
just VM_SHARED isn't actually sufficient.

So use a trivial helper function for the cases where we wanted to inquire
if a mapping was COW-like or not.

Moo!

Signed-off-by: Linus Torvalds

Remove (at least temporarily) the "incomplete PFN mapping" support

2005-12-12T03:57:52+00:00

With the previous commit, we can handle arbitrary shared re-mappings
even without this complexity, and since the only known private mappings
are for strange users of /dev/mem (which never create an incomplete one),
there seems to be no reason to support it.

Signed-off-by: Linus Torvalds

Allow arbitrary shared PFNMAP's

2005-12-12T03:46:02+00:00

A shared mapping doesn't cause COW-pages, so we don't need to worry
about the whole vm_pgoff logic to decide if a PFN-remapped page has
gone through COW or not.

This makes it possible to entirely avoid the special "partial remapping"
logic for the common case.

Signed-off-by: Linus Torvalds

Make vm_insert_page() available to NVidia module

2005-12-04T04:48:11+00:00

It used to use remap_pfn_range(), which wasn't GPL-only either, and the
new interface is actually simpler and does more checking, so we
shouldn't unnecessarily discourage people from switching over.

Signed-off-by: Linus Torvalds

VM: add "vm_insert_page()" function

2005-11-30T17:35:19+00:00

This is what a lot of drivers will actually want to use to insert
individual pages into a user VMA.  It doesn't have the old PageReserved
restrictions of remap_pfn_range(), and it doesn't complain about partial
remappings.

The page you insert needs to be a nice clean kernel allocation, so you
can't insert arbitrary page mappings with this, but that's not what
people want.

Signed-off-by: Linus Torvalds

[PATCH] VM: Fix typos in get_locked_pte

2005-11-30T01:29:57+00:00

Signed-off-by: Trond Myklebust 
Signed-off-by: Linus Torvalds

[PATCH] pfnmap: do_no_page BUG_ON again

2005-11-29T22:09:17+00:00

Use copy_user_highpage directly instead of cow_user_page in do_no_page:
in the immediately following page_cache_release, and elsewhere, it is
assuming that new_page is normal.  If any VM_PFNMAP driver can get to
do_no_page, it's just a BUG (but not in the case of do_anonymous_page).

Signed-off-by: Hugh Dickins 
Signed-off-by: Linus Torvalds

[PATCH] pfnmap: remove src_page from do_wp_page

2005-11-29T22:09:16+00:00

Clean away do_wp_page's "src_page": cow_user_page makes it unnecessary.

Signed-off-by: Hugh Dickins 
Signed-off-by: Linus Torvalds