diff options
| author | Matthew Wilcox <mawilcox@microsoft.com> | 2018-06-07 17:08:31 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-07 17:34:37 -0700 |
| commit | 7d27a04bb2b5bd665f147439d18ae236080eef32 (patch) | |
| tree | 2798e10870a5932a694807b58215da370d1efb06 /include | |
| parent | d4fc5069a39405d67937b25c0dc9249a9b6c50f1 (diff) | |
mm: move 'private' union within struct page
By moving page->private to the fourth word of struct page, we can put the
SLUB counters in the same word as SLAB's s_mem and still do the
cmpxchg_double trick. Now the SLUB counters no longer overlap with the
mapcount or refcount so we can drop the call to page_mapcount_reset() and
simplify set_page_slub_counters() to a single line.
Link: http://lkml.kernel.org/r/20180518194519.3820-6-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
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>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/mm_types.h | 56 |
1 files changed, 25 insertions, 31 deletions
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 6f153f2fab50..bcc5ee8b7b07 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -65,15 +65,9 @@ struct hmm; */ #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE #define _struct_page_alignment __aligned(2 * sizeof(unsigned long)) -#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) -#define _slub_counter_t unsigned long #else -#define _slub_counter_t unsigned int -#endif -#else /* !CONFIG_HAVE_ALIGNED_STRUCT_PAGE */ #define _struct_page_alignment -#define _slub_counter_t unsigned int -#endif /* !CONFIG_HAVE_ALIGNED_STRUCT_PAGE */ +#endif struct page { /* First double word block */ @@ -97,6 +91,30 @@ struct page { union { /* + * Mapping-private opaque data: + * Usually used for buffer_heads if PagePrivate + * Used for swp_entry_t if PageSwapCache + * Indicates order in the buddy system if PageBuddy + */ + unsigned long private; +#if USE_SPLIT_PTE_PTLOCKS +#if ALLOC_SPLIT_PTLOCKS + spinlock_t *ptl; +#else + spinlock_t ptl; +#endif +#endif + void *s_mem; /* slab first object */ + unsigned long counters; /* SLUB */ + struct { /* SLUB */ + unsigned inuse:16; + unsigned objects:15; + unsigned frozen:1; + }; + }; + + union { + /* * If the page is neither PageSlab nor mappable to userspace, * the value stored here may help determine what this page * is used for. See page-flags.h for a list of page types @@ -104,13 +122,7 @@ struct page { */ unsigned int page_type; - _slub_counter_t counters; unsigned int active; /* SLAB */ - struct { /* SLUB */ - unsigned inuse:16; - unsigned objects:15; - unsigned frozen:1; - }; int units; /* SLOB */ struct { /* Page cache */ @@ -179,24 +191,6 @@ struct page { #endif }; - union { - /* - * Mapping-private opaque data: - * Usually used for buffer_heads if PagePrivate - * Used for swp_entry_t if PageSwapCache - * Indicates order in the buddy system if PageBuddy - */ - unsigned long private; -#if USE_SPLIT_PTE_PTLOCKS -#if ALLOC_SPLIT_PTLOCKS - spinlock_t *ptl; -#else - spinlock_t ptl; -#endif -#endif - void *s_mem; /* slab first object */ - }; - #ifdef CONFIG_MEMCG struct mem_cgroup *mem_cgroup; #endif |