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author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2015-02-12 00:25:50 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-12 02:06:02 +0100 |
commit | 6e9f0d582dde095d971a3c6ce4685a218a0eac8e (patch) | |
tree | 6c6500ae0a15e86294732b039c9db03b5153a301 /mm/page_alloc.c | |
parent | mm: microoptimize zonelist operations (diff) | |
download | linux-6e9f0d582dde095d971a3c6ce4685a218a0eac8e.tar.xz linux-6e9f0d582dde095d971a3c6ce4685a218a0eac8e.zip |
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>
Diffstat (limited to 'mm/page_alloc.c')
-rw-r--r-- | mm/page_alloc.c | 35 |
1 files changed, 1 insertions, 34 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d664eb922a7d..12d55b859d3f 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -381,36 +381,6 @@ void prep_compound_page(struct page *page, unsigned long order) } } -/* update __split_huge_page_refcount if you change this function */ -static int destroy_compound_page(struct page *page, unsigned long order) -{ - int i; - int nr_pages = 1 << order; - int bad = 0; - - if (unlikely(compound_order(page) != order)) { - bad_page(page, "wrong compound order", 0); - bad++; - } - - __ClearPageHead(page); - - for (i = 1; i < nr_pages; i++) { - struct page *p = page + i; - - if (unlikely(!PageTail(p))) { - bad_page(page, "PageTail not set", 0); - bad++; - } else if (unlikely(p->first_page != page)) { - bad_page(page, "first_page not consistent", 0); - bad++; - } - __ClearPageTail(p); - } - - return bad; -} - static inline void prep_zero_page(struct page *page, unsigned int order, gfp_t gfp_flags) { @@ -613,10 +583,7 @@ static inline void __free_one_page(struct page *page, int max_order = MAX_ORDER; VM_BUG_ON(!zone_is_initialized(zone)); - - if (unlikely(PageCompound(page))) - if (unlikely(destroy_compound_page(page, order))) - return; + VM_BUG_ON_PAGE(page->flags & PAGE_FLAGS_CHECK_AT_PREP, page); VM_BUG_ON(migratetype == -1); if (is_migrate_isolate(migratetype)) { |