Commit Graph

4 Commits

Author SHA1 Message Date
Christoph Lameter 4c28f81193 [PATCH] page migration: Fix fallback behavior for dirty pages
Currently we check PageDirty() in order to make the decision to swap out
the page.  However, the dirty information may be only be contained in the
ptes pointing to the page.  We need to first unmap the ptes before checking
for PageDirty().  If unmap is successful then the page count of the page
will also be decreased so that pageout() works properly.

This is a fix necessary for 2.6.17.  Without this fix we may migrate dirty
pages for filesystems without migration functions.  Filesystems may keep
pointers to dirty pages.  Migration of dirty pages can result in the
filesystem keeping pointers to freed pages.

Unmapping is currently not be separated out from removing all the
references to a page and moving the mapping.  Therefore try_to_unmap will
be called again in migrate_page() if the writeout is successful.  However,
it wont do anything since the ptes are already removed.

The coming updates to the page migration code will restructure the code
so that this is no longer necessary.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-01 18:17:45 -07:00
Adrian Bunk 64a3ca5f7e [PATCH] mm/migrate.c: don't export a static function
EXPORT_SYMBOL'ing of a static function is not a good idea.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Christoph Lameter <clameter@engr.sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:33 -07:00
Christoph Lameter e23ca00bf1 [PATCH] Some page migration fixups
- Remove sparse comment

- Remove duplicated include

- Return the correct error condition in migrate_page_remove_references().

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-04-11 06:18:32 -07:00
Christoph Lameter b20a35035f [PATCH] page migration reorg
Centralize the page migration functions in anticipation of additional
tinkering.  Creates a new file mm/migrate.c

1. Extract buffer_migrate_page() from fs/buffer.c

2. Extract central migration code from vmscan.c

3. Extract some components from mempolicy.c

4. Export pageout() and remove_from_swap() from vmscan.c

5. Make it possible to configure NUMA systems without page migration
   and non-NUMA systems with page migration.

I had to so some #ifdeffing in mempolicy.c that may need a cleanup.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-22 07:54:06 -08:00