mm: split page_type out from _mapcount
We're already using a union of many fields here, so stop abusing the
_mapcount and make page_type its own field. That implies renaming some of
the machinery that creates PageBuddy, PageBalloon and PageKmemcg; bring
back the PG_buddy, PG_balloon and PG_kmemcg names.
As suggested by Kirill, make page_type a bitmask. Because it starts out
life as -1 (thanks to sharing the storage with _mapcount), setting a page
flag means clearing the appropriate bit. This gives us space for probably
twenty or so extra bits (depending how paranoid we want to be about
_mapcount underflow).
Link: http://lkml.kernel.org/r/20180518194519.3820-3-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/scripts/tags.sh b/scripts/tags.sh
index e587610..66f08bb 100755
--- a/scripts/tags.sh
+++ b/scripts/tags.sh
@@ -179,9 +179,9 @@
'/\<CLEARPAGEFLAG_NOOP(\([[:alnum:]_]*\).*/ClearPage\1/'
'/\<__CLEARPAGEFLAG_NOOP(\([[:alnum:]_]*\).*/__ClearPage\1/'
'/\<TESTCLEARFLAG_FALSE(\([[:alnum:]_]*\).*/TestClearPage\1/'
- '/^PAGE_MAPCOUNT_OPS(\([[:alnum:]_]*\).*/Page\1/'
- '/^PAGE_MAPCOUNT_OPS(\([[:alnum:]_]*\).*/__SetPage\1/'
- '/^PAGE_MAPCOUNT_OPS(\([[:alnum:]_]*\).*/__ClearPage\1/'
+ '/^PAGE_TYPE_OPS(\([[:alnum:]_]*\).*/Page\1/'
+ '/^PAGE_TYPE_OPS(\([[:alnum:]_]*\).*/__SetPage\1/'
+ '/^PAGE_TYPE_OPS(\([[:alnum:]_]*\).*/__ClearPage\1/'
'/^TASK_PFA_TEST([^,]*, *\([[:alnum:]_]*\))/task_\1/'
'/^TASK_PFA_SET([^,]*, *\([[:alnum:]_]*\))/task_set_\1/'
'/^TASK_PFA_CLEAR([^,]*, *\([[:alnum:]_]*\))/task_clear_\1/'
