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

[deliverable/linux.git] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index 6768ce9e57d29b6d8076b11c62c2097662f334d5..86487dfa5e59bd4ecac8c09445cce49b435e8c29 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -59,6 +59,7 @@
 #include <linux/gfp.h>
 #include <linux/migrate.h>
 #include <linux/string.h>
+#include <linux/dma-debug.h>
 
 #include <asm/io.h>
 #include <asm/pgalloc.h>
@@ -2559,6 +2560,8 @@ static inline int pte_unmap_same(struct mm_struct *mm, pmd_t *pmd,
 
 static inline void cow_user_page(struct page *dst, struct page *src, unsigned long va, struct vm_area_struct *vma)
 {
+       debug_dma_assert_idle(src);
+
        /*
         * If the source page was a PFN mapping, we don't have
         * a "struct page" for it. We do a best-effort copy by
@@ -4272,11 +4275,20 @@ void copy_user_huge_page(struct page *dst, struct page *src,
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
 
 #if USE_SPLIT_PTE_PTLOCKS && ALLOC_SPLIT_PTLOCKS
+
+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;
 
-       ptl = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
+       ptl = kmem_cache_alloc(page_ptl_cachep, GFP_KERNEL);
        if (!ptl)
                return false;
        page->ptl = ptl;
@@ -4285,6 +4297,6 @@ bool ptlock_alloc(struct page *page)
 
 void ptlock_free(struct page *page)
 {
-       kfree(page->ptl);
+       kmem_cache_free(page_ptl_cachep, page->ptl);
 }
 #endif