mm: Remove slab from struct page

All members of struct slab can now be removed from struct page.
This shrinks the definition of struct page by 30 LOC, making
it easier to understand.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 1ae3537c792072deecba06b445367fb3773d696f..646f3ed4f6df038a219fcfa29107790010439918 100644 (file)
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -118,31 +118,6 @@ struct page {
                                atomic_long_t pp_frag_count;
                        };
                };
-               struct {        /* slab, slob and slub */
-                       union {
-                               struct list_head slab_list;
-                               struct {        /* Partial pages */
-                                       struct page *next;
-#ifdef CONFIG_64BIT
-                                       int pages;      /* Nr of pages left */
-#else
-                                       short int pages;
-#endif
-                               };
-                       };
-                       struct kmem_cache *slab_cache; /* not slob */
-                       /* Double-word boundary */
-                       void *freelist;         /* first free object */
-                       union {
-                               void *s_mem;    /* slab: first object */
-                               unsigned long counters;         /* SLUB */
-                               struct {                        /* SLUB */
-                                       unsigned inuse:16;
-                                       unsigned objects:15;
-                                       unsigned frozen:1;
-                               };
-                       };
-               };
                struct {        /* Tail pages of compound page */
                        unsigned long compound_head;    /* Bit zero is set */
 
@@ -206,9 +181,6 @@ struct page {
                 * which are currently stored here.
                 */
                unsigned int page_type;
-
-               unsigned int active;            /* SLAB */
-               int units;                      /* SLOB */
        };
 
        /* Usage count. *DO NOT USE DIRECTLY*. See page_ref.h */

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index b5f14d5811135fc24c50ccf37234885fd0bed6f6..1b08e33265fa8b8e63772e9b50a92a1043481fbe 100644 (file)
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -909,43 +909,6 @@ extern bool is_free_buddy_page(struct page *page);
 
 __PAGEFLAG(Isolated, isolated, PF_ANY);
 
-/*
- * If network-based swap is enabled, sl*b must keep track of whether pages
- * were allocated from pfmemalloc reserves.
- */
-static inline int PageSlabPfmemalloc(struct page *page)
-{
-       VM_BUG_ON_PAGE(!PageSlab(page), page);
-       return PageActive(page);
-}
-
-/*
- * A version of PageSlabPfmemalloc() for opportunistic checks where the page
- * might have been freed under us and not be a PageSlab anymore.
- */
-static inline int __PageSlabPfmemalloc(struct page *page)
-{
-       return PageActive(page);
-}
-
-static inline void SetPageSlabPfmemalloc(struct page *page)
-{
-       VM_BUG_ON_PAGE(!PageSlab(page), page);
-       SetPageActive(page);
-}
-
-static inline void __ClearPageSlabPfmemalloc(struct page *page)
-{
-       VM_BUG_ON_PAGE(!PageSlab(page), page);
-       __ClearPageActive(page);
-}
-
-static inline void ClearPageSlabPfmemalloc(struct page *page)
-{
-       VM_BUG_ON_PAGE(!PageSlab(page), page);
-       ClearPageActive(page);
-}
-
 #ifdef CONFIG_MMU
 #define __PG_MLOCKED           (1UL << PG_mlocked)
 #else

diff --git a/mm/slab.h b/mm/slab.h
index 95b9a74a2d515fd83091253b786886be9cc08476..207658b200ef10663338229d28d7472dfe5a42a9 100644 (file)
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -67,14 +67,8 @@ struct slab {
        static_assert(offsetof(struct page, pg) == offsetof(struct slab, sl))
 SLAB_MATCH(flags, __page_flags);
 SLAB_MATCH(compound_head, slab_list);  /* Ensure bit 0 is clear */
-SLAB_MATCH(slab_list, slab_list);
 #ifndef CONFIG_SLOB
 SLAB_MATCH(rcu_head, rcu_head);
-SLAB_MATCH(slab_cache, slab_cache);
-#endif
-#ifdef CONFIG_SLAB
-SLAB_MATCH(s_mem, s_mem);
-SLAB_MATCH(active, active);
 #endif
 SLAB_MATCH(_refcount, __page_refcount);
 #ifdef CONFIG_MEMCG