Revert "mm: create a separate slab for page->ptl allocation"

This reverts commit ea1e7ed33708c7a760419ff9ded0a6cb90586a50.

Al points out that while the commit *does* actually create a separate
slab for the page->ptl allocation, that slab is never actually used, and
the code continues to use kmalloc/kfree.

Damien Wyart points out that the original patch did have the conversion
to use kmem_cache_alloc/free, so it got lost somewhere on its way to me.

Revert the half-arsed attempt that didn't do anything.  If we really do
want the special slab (remember: this is all relevant just for debug
builds, so it's not necessarily all that critical) we might as well redo
the patch fully.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Kirill A Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 0548eb201e058afdd32f2645240633ff7a8783d4..1cedd000cf293f4486575b87086b01e2ee1b26e5 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1318,7 +1318,6 @@ static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long a
 
 #if USE_SPLIT_PTE_PTLOCKS
 #if BLOATED_SPINLOCKS
-void __init ptlock_cache_init(void);
 extern bool ptlock_alloc(struct page *page);
 extern void ptlock_free(struct page *page);
 
@@ -1327,7 +1326,6 @@ static inline spinlock_t *ptlock_ptr(struct page *page)
        return page->ptl;
 }
 #else /* BLOATED_SPINLOCKS */
-static inline void ptlock_cache_init(void) {}
 static inline bool ptlock_alloc(struct page *page)
 {
        return true;
@@ -1380,17 +1378,10 @@ static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
 {
        return &mm->page_table_lock;
 }
-static inline void ptlock_cache_init(void) {}
 static inline bool ptlock_init(struct page *page) { return true; }
 static inline void pte_lock_deinit(struct page *page) {}
 #endif /* USE_SPLIT_PTE_PTLOCKS */
 
-static inline void pgtable_init(void)
-{
-       ptlock_cache_init();
-       pgtable_cache_init();
-}
-
 static inline bool pgtable_page_ctor(struct page *page)
 {
        inc_zone_page_state(page, NR_PAGETABLE);

diff --git a/init/main.c b/init/main.c
index 01573fdfa1868fd7fb320d472eff6217f39a07eb..febc511e078a65d08ac4dd6a3be67b26926195cd 100644 (file)
--- a/init/main.c
+++ b/init/main.c
@@ -476,7 +476,7 @@ static void __init mm_init(void)
        mem_init();
        kmem_cache_init();
        percpu_init_late();
-       pgtable_init();
+       pgtable_cache_init();
        vmalloc_init();
 }
 

diff --git a/mm/memory.c b/mm/memory.c
index 0409e8f43fa0f3719fadf3f19afda45164bbaa94..5d9025f3b3e1cd65bd97655ee95d6cd2f390ce5b 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4272,13 +4272,6 @@ void copy_user_huge_page(struct page *dst, struct page *src,
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
 
 #if USE_SPLIT_PTE_PTLOCKS && BLOATED_SPINLOCKS
-static struct kmem_cache *page_ptl_cachep;
-void __init ptlock_cache_init(void)
-{
-       page_ptl_cachep = kmem_cache_create("page->ptl", sizeof(spinlock_t), 0,
-                       SLAB_PANIC, NULL);
-}
-
 bool ptlock_alloc(struct page *page)
 {
        spinlock_t *ptl;