[PATCH 04/16] mm/slab: activate debug_pagealloc in SLAB when it is actually enabled

From: Joonsoo Kim
Date: Thu Jan 14 2016 - 00:28:37 EST


Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
---
mm/slab.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index bbe4df2..4b55516 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1838,7 +1838,8 @@ static void slab_destroy_debugcheck(struct kmem_cache *cachep,

if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
- if (cachep->size % PAGE_SIZE == 0 &&
+ if (debug_pagealloc_enabled() &&
+ cachep->size % PAGE_SIZE == 0 &&
OFF_SLAB(cachep))
kernel_map_pages(virt_to_page(objp),
cachep->size / PAGE_SIZE, 1);
@@ -2176,7 +2177,8 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
* to check size >= 256. It guarantees that all necessary small
* sized slab is initialized in current slab initialization sequence.
*/
- if (!slab_early_init && size >= kmalloc_size(INDEX_NODE) &&
+ if (debug_pagealloc_enabled() &&
+ !slab_early_init && size >= kmalloc_size(INDEX_NODE) &&
size >= 256 && cachep->object_size > cache_line_size() &&
ALIGN(size, cachep->align) < PAGE_SIZE) {
cachep->obj_offset += PAGE_SIZE - ALIGN(size, cachep->align);
@@ -2232,7 +2234,8 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
* poisoning, then it's going to smash the contents of
* the redzone and userword anyhow, so switch them off.
*/
- if (size % PAGE_SIZE == 0 && flags & SLAB_POISON)
+ if (debug_pagealloc_enabled() &&
+ size % PAGE_SIZE == 0 && flags & SLAB_POISON)
flags &= ~(SLAB_RED_ZONE | SLAB_STORE_USER);
#endif
}
@@ -2716,7 +2719,8 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
set_obj_status(page, objnr, OBJECT_FREE);
if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
- if ((cachep->size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
+ if (debug_pagealloc_enabled() &&
+ (cachep->size % PAGE_SIZE) == 0 && OFF_SLAB(cachep)) {
store_stackinfo(cachep, objp, caller);
kernel_map_pages(virt_to_page(objp),
cachep->size / PAGE_SIZE, 0);
@@ -2861,7 +2865,8 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
return objp;
if (cachep->flags & SLAB_POISON) {
#ifdef CONFIG_DEBUG_PAGEALLOC
- if ((cachep->size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
+ if (debug_pagealloc_enabled() &&
+ (cachep->size % PAGE_SIZE) == 0 && OFF_SLAB(cachep))
kernel_map_pages(virt_to_page(objp),
cachep->size / PAGE_SIZE, 1);
else
--
1.9.1