mm/page_alloc.c: drop dead destroy_compound_page()
authorKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Wed, 11 Feb 2015 23:25:50 +0000 (15:25 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 12 Feb 2015 01:06:02 +0000 (17:06 -0800)
commit6e9f0d582dde095d971a3c6ce4685a218a0eac8e
tree6c6500ae0a15e86294732b039c9db03b5153a301
parent05891fb06517d19ae5357c9dc44e96bbe0300a3c
mm/page_alloc.c: drop dead destroy_compound_page()

The only caller is __free_one_page(). By the time we should have
page->flags to be cleared already:

 - for 0-order pages though PCP list:
free_hot_cold_page()
free_pages_prepare()
free_pages_check()
page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
<put the page to PCP list>

free_pcppages_bulk()
page = <withdraw pages from PCP list>
__free_one_page(page)

 - for non-0-order pages:
__free_pages_ok()
free_pages_prepare()
free_pages_check()
page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
free_one_page()
__free_one_page()

So there's no way PageCompound() will return true in __free_one_page().
Let's remove dead destroy_compound_page() and put assert for page->flags
there instead.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/page_alloc.c