tree c82d27461f2adda210e77808b7dd04eaec017f2f
parent 21ae5b01750f14140809508a478a4413792e0261
author Andrea Arcangeli <aarcange@redhat.com> 1294962420 -0800
committer Linus Torvalds <torvalds@linux-foundation.org> 1294968763 -0800

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>