| commit | 5f24ce5fd34c3ca1b3d10d30da754732da64d5c0 | |
| author | Andrea Arcangeli <aarcange@redhat.com> | |
| Thu, 13 Jan 2011 23:47:00 +0000 (13 15:47 -0800) | ||
| committer | Linus Torvalds <torvalds@linux-foundation.org> | |
| Fri, 14 Jan 2011 01:32:43 +0000 (13 17:32 -0800) | ||
| tree | c82d27461f2adda210e77808b7dd04eaec017f2f | treesnapshot (tar.gz zip) |
| parent | 21ae5b01750f14140809508a478a4413792e0261 | commitdiff |
thp: remove PG_buddy
PG_buddy can be converted to _mapcount == -2. So the PG_compound_lock can
be added to page->flags without overflowing (because of the sparse section
bits increasing) with CONFIG_X86_PAE=y and CONFIG_X86_PAT=y. This also
has to move the memory hotplug code from _mapcount to lru.next to avoid
any risk of clashes. We can't use lru.next for PG_buddy removal, but
memory hotplug can use lru.next even more easily than the mapcount
instead.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PG_buddy can be converted to _mapcount == -2. So the PG_compound_lock can
be added to page->flags without overflowing (because of the sparse section
bits increasing) with CONFIG_X86_PAE=y and CONFIG_X86_PAT=y. This also
has to move the memory hotplug code from _mapcount to lru.next to avoid
any risk of clashes. We can't use lru.next for PG_buddy removal, but
memory hotplug can use lru.next even more easily than the mapcount
instead.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>