page migraton: handle orphaned pages
commit62e1c55300f306e06478f460a7eefba085206e0b
authorShaohua Li <shaohua.li@intel.com>
Tue, 5 Feb 2008 06:29:33 +0000 (4 22:29 -0800)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Tue, 5 Feb 2008 17:44:19 +0000 (5 09:44 -0800)
treebe15b2e4801c837c5e20d43b8f29a53c0ba1391c
parent7786fa9ac5366214fb942a9e62c6e46b4272c22c
page migraton: handle orphaned pages

Orphaned page might have fs-private metadata, the page is truncated.  As
the page hasn't mapping, page migration refuse to migrate the page.  It
appears the page is only freed in page reclaim and if zone watermark is
low, the page is never freed, as a result migration always fail.  I thought
we could free the metadata so such page can be freed in migration and make
migration more reliable.

[akpm@linux-foundation.org: go direct to try_to_free_buffers()]
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Acked-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/migrate.c
mm/truncate.c