From 73293c2f900d0adbb6a415b312cd57976d5ae242 Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 24 Oct 2013 10:07:37 +0900
Subject: slab: correct pfmemalloc check

We checked pfmemalloc by slab unit, not page unit. You can see this
in is_slab_pfmemalloc(). So other pages don't need to be set/cleared
pfmemalloc.

And, therefore we should check pfmemalloc in page flag of first page,
but current implementation don't do that. virt_to_head_page(obj) just
return 'struct page' of that object, not one of first page, since the SLAB
don't use __GFP_COMP when CONFIG_MMU. To get 'struct page' of first page,
we first get a slab and try to get it via virt_to_head_page(slab->s_mem).

Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index 2580db062df9..0b4ddafd8a03 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -930,7 +930,8 @@ static void *__ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac,
 {
 	if (unlikely(pfmemalloc_active)) {
 		/* Some pfmemalloc slabs exist, check if this is one */
-		struct page *page = virt_to_head_page(objp);
+		struct slab *slabp = virt_to_slab(objp);
+		struct page *page = virt_to_head_page(slabp->s_mem);
 		if (PageSlabPfmemalloc(page))
 			set_obj_pfmemalloc(&objp);
 	}
@@ -1776,7 +1777,7 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
 		__SetPageSlab(page + i);
 
 		if (page->pfmemalloc)
-			SetPageSlabPfmemalloc(page + i);
+			SetPageSlabPfmemalloc(page);
 	}
 	memcg_bind_pages(cachep, cachep->gfporder);
 
@@ -1809,9 +1810,10 @@ static void kmem_freepages(struct kmem_cache *cachep, void *addr)
 	else
 		sub_zone_page_state(page_zone(page),
 				NR_SLAB_UNRECLAIMABLE, nr_freed);
+
+	__ClearPageSlabPfmemalloc(page);
 	while (i--) {
 		BUG_ON(!PageSlab(page));
-		__ClearPageSlabPfmemalloc(page);
 		__ClearPageSlab(page);
 		page++;
 	}
-- 
cgit v1.2.3


From 0c3aa83e00a9cd93f08e7aa42fba01924aa5f2fc Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 24 Oct 2013 10:07:38 +0900
Subject: slab: change return type of kmem_getpages() to struct page

It is more understandable that kmem_getpages() return struct page.
And, with this, we can reduce one translation from virt addr to page and
makes better code than before. Below is a change of this patch.

* Before
   text	   data	    bss	    dec	    hex	filename
  22123	  23434	      4	  45561	   b1f9	mm/slab.o

* After
   text	   data	    bss	    dec	    hex	filename
  22074	  23434	      4	  45512	   b1c8	mm/slab.o

And this help following patch to remove struct slab's colouroff.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 60 ++++++++++++++++++++++++++++++------------------------------
 1 file changed, 30 insertions(+), 30 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index 0b4ddafd8a03..7d79bd766002 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -205,7 +205,7 @@ typedef unsigned int kmem_bufctl_t;
 struct slab_rcu {
 	struct rcu_head head;
 	struct kmem_cache *cachep;
-	void *addr;
+	struct page *page;
 };
 
 /*
@@ -1737,7 +1737,8 @@ slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid)
  * did not request dmaable memory, we might get it, but that
  * would be relatively rare and ignorable.
  */
-static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
+static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
+								int nodeid)
 {
 	struct page *page;
 	int nr_pages;
@@ -1790,16 +1791,15 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
 			kmemcheck_mark_unallocated_pages(page, nr_pages);
 	}
 
-	return page_address(page);
+	return page;
 }
 
 /*
  * Interface to system's page release.
  */
-static void kmem_freepages(struct kmem_cache *cachep, void *addr)
+static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
 {
 	unsigned long i = (1 << cachep->gfporder);
-	struct page *page = virt_to_page(addr);
 	const unsigned long nr_freed = i;
 
 	kmemcheck_free_shadow(page, cachep->gfporder);
@@ -1821,7 +1821,7 @@ static void kmem_freepages(struct kmem_cache *cachep, void *addr)
 	memcg_release_pages(cachep, cachep->gfporder);
 	if (current->reclaim_state)
 		current->reclaim_state->reclaimed_slab += nr_freed;
-	free_memcg_kmem_pages((unsigned long)addr, cachep->gfporder);
+	__free_memcg_kmem_pages(page, cachep->gfporder);
 }
 
 static void kmem_rcu_free(struct rcu_head *head)
@@ -1829,7 +1829,7 @@ static void kmem_rcu_free(struct rcu_head *head)
 	struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
 	struct kmem_cache *cachep = slab_rcu->cachep;
 
-	kmem_freepages(cachep, slab_rcu->addr);
+	kmem_freepages(cachep, slab_rcu->page);
 	if (OFF_SLAB(cachep))
 		kmem_cache_free(cachep->slabp_cache, slab_rcu);
 }
@@ -2048,7 +2048,7 @@ static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slab
  */
 static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
 {
-	void *addr = slabp->s_mem - slabp->colouroff;
+	struct page *page = virt_to_head_page(slabp->s_mem);
 
 	slab_destroy_debugcheck(cachep, slabp);
 	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
@@ -2056,10 +2056,10 @@ static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
 
 		slab_rcu = (struct slab_rcu *)slabp;
 		slab_rcu->cachep = cachep;
-		slab_rcu->addr = addr;
+		slab_rcu->page = page;
 		call_rcu(&slab_rcu->head, kmem_rcu_free);
 	} else {
-		kmem_freepages(cachep, addr);
+		kmem_freepages(cachep, page);
 		if (OFF_SLAB(cachep))
 			kmem_cache_free(cachep->slabp_cache, slabp);
 	}
@@ -2604,11 +2604,12 @@ int __kmem_cache_shutdown(struct kmem_cache *cachep)
  * kmem_find_general_cachep till the initialization is complete.
  * Hence we cannot have slabp_cache same as the original cache.
  */
-static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
-				   int colour_off, gfp_t local_flags,
-				   int nodeid)
+static struct slab *alloc_slabmgmt(struct kmem_cache *cachep,
+				   struct page *page, int colour_off,
+				   gfp_t local_flags, int nodeid)
 {
 	struct slab *slabp;
+	void *addr = page_address(page);
 
 	if (OFF_SLAB(cachep)) {
 		/* Slab management obj is off-slab. */
@@ -2625,12 +2626,12 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
 		if (!slabp)
 			return NULL;
 	} else {
-		slabp = objp + colour_off;
+		slabp = addr + colour_off;
 		colour_off += cachep->slab_size;
 	}
 	slabp->inuse = 0;
 	slabp->colouroff = colour_off;
-	slabp->s_mem = objp + colour_off;
+	slabp->s_mem = addr + colour_off;
 	slabp->nodeid = nodeid;
 	slabp->free = 0;
 	return slabp;
@@ -2741,12 +2742,9 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
  * virtual address for kfree, ksize, and slab debugging.
  */
 static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
-			   void *addr)
+			   struct page *page)
 {
 	int nr_pages;
-	struct page *page;
-
-	page = virt_to_page(addr);
 
 	nr_pages = 1;
 	if (likely(!PageCompound(page)))
@@ -2764,7 +2762,7 @@ static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
  * kmem_cache_alloc() when there are no active objs left in a cache.
  */
 static int cache_grow(struct kmem_cache *cachep,
-		gfp_t flags, int nodeid, void *objp)
+		gfp_t flags, int nodeid, struct page *page)
 {
 	struct slab *slabp;
 	size_t offset;
@@ -2807,18 +2805,18 @@ static int cache_grow(struct kmem_cache *cachep,
 	 * Get mem for the objs.  Attempt to allocate a physical page from
 	 * 'nodeid'.
 	 */
-	if (!objp)
-		objp = kmem_getpages(cachep, local_flags, nodeid);
-	if (!objp)
+	if (!page)
+		page = kmem_getpages(cachep, local_flags, nodeid);
+	if (!page)
 		goto failed;
 
 	/* Get slab management. */
-	slabp = alloc_slabmgmt(cachep, objp, offset,
+	slabp = alloc_slabmgmt(cachep, page, offset,
 			local_flags & ~GFP_CONSTRAINT_MASK, nodeid);
 	if (!slabp)
 		goto opps1;
 
-	slab_map_pages(cachep, slabp, objp);
+	slab_map_pages(cachep, slabp, page);
 
 	cache_init_objs(cachep, slabp);
 
@@ -2834,7 +2832,7 @@ static int cache_grow(struct kmem_cache *cachep,
 	spin_unlock(&n->list_lock);
 	return 1;
 opps1:
-	kmem_freepages(cachep, objp);
+	kmem_freepages(cachep, page);
 failed:
 	if (local_flags & __GFP_WAIT)
 		local_irq_disable();
@@ -3250,18 +3248,20 @@ retry:
 		 * We may trigger various forms of reclaim on the allowed
 		 * set and go into memory reserves if necessary.
 		 */
+		struct page *page;
+
 		if (local_flags & __GFP_WAIT)
 			local_irq_enable();
 		kmem_flagcheck(cache, flags);
-		obj = kmem_getpages(cache, local_flags, numa_mem_id());
+		page = kmem_getpages(cache, local_flags, numa_mem_id());
 		if (local_flags & __GFP_WAIT)
 			local_irq_disable();
-		if (obj) {
+		if (page) {
 			/*
 			 * Insert into the appropriate per node queues
 			 */
-			nid = page_to_nid(virt_to_page(obj));
-			if (cache_grow(cache, flags, nid, obj)) {
+			nid = page_to_nid(page);
+			if (cache_grow(cache, flags, nid, page)) {
 				obj = ____cache_alloc_node(cache,
 					flags | GFP_THISNODE, nid);
 				if (!obj)
-- 
cgit v1.2.3


From ac2b54edbc4768f4a069fc360e2b4e579e9907cb Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 24 Oct 2013 10:07:39 +0900
Subject: slab: remove colouroff in struct slab

Now there is no user colouroff, so remove it.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 2 --
 1 file changed, 2 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index 7d79bd766002..34eb1152aba4 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -219,7 +219,6 @@ struct slab {
 	union {
 		struct {
 			struct list_head list;
-			unsigned long colouroff;
 			void *s_mem;		/* including colour offset */
 			unsigned int inuse;	/* num of objs active in slab */
 			kmem_bufctl_t free;
@@ -2630,7 +2629,6 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep,
 		colour_off += cachep->slab_size;
 	}
 	slabp->inuse = 0;
-	slabp->colouroff = colour_off;
 	slabp->s_mem = addr + colour_off;
 	slabp->nodeid = nodeid;
 	slabp->free = 0;
-- 
cgit v1.2.3


From 1ea991b00c26e3a275e2d2e110e5221211fc45b6 Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 24 Oct 2013 10:07:40 +0900
Subject: slab: remove nodeid in struct slab

We can get nodeid using address translation, so this field is not useful.
Therefore, remove it.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index 34eb1152aba4..71ba8f53f9b7 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -222,7 +222,6 @@ struct slab {
 			void *s_mem;		/* including colour offset */
 			unsigned int inuse;	/* num of objs active in slab */
 			kmem_bufctl_t free;
-			unsigned short nodeid;
 		};
 		struct slab_rcu __slab_cover_slab_rcu;
 	};
@@ -1099,8 +1098,7 @@ static void drain_alien_cache(struct kmem_cache *cachep,
 
 static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
 {
-	struct slab *slabp = virt_to_slab(objp);
-	int nodeid = slabp->nodeid;
+	int nodeid = page_to_nid(virt_to_page(objp));
 	struct kmem_cache_node *n;
 	struct array_cache *alien = NULL;
 	int node;
@@ -1111,7 +1109,7 @@ static inline int cache_free_alien(struct kmem_cache *cachep, void *objp)
 	 * Make sure we are not freeing a object from another node to the array
 	 * cache on this cpu.
 	 */
-	if (likely(slabp->nodeid == node))
+	if (likely(nodeid == node))
 		return 0;
 
 	n = cachep->node[node];
@@ -2630,7 +2628,6 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep,
 	}
 	slabp->inuse = 0;
 	slabp->s_mem = addr + colour_off;
-	slabp->nodeid = nodeid;
 	slabp->free = 0;
 	return slabp;
 }
@@ -2707,7 +2704,7 @@ static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
 	next = slab_bufctl(slabp)[slabp->free];
 #if DEBUG
 	slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
-	WARN_ON(slabp->nodeid != nodeid);
+	WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
 #endif
 	slabp->free = next;
 
@@ -2721,7 +2718,7 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
 
 #if DEBUG
 	/* Verify that the slab belongs to the intended node */
-	WARN_ON(slabp->nodeid != nodeid);
+	WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
 
 	if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
 		printk(KERN_ERR "slab: double free detected in cache "
-- 
cgit v1.2.3


From 07d417a1c6f1e386a2276b0cae8ae1d14b8a32cc Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 24 Oct 2013 10:07:41 +0900
Subject: slab: remove cachep in struct slab_rcu

We can get cachep using page in struct slab_rcu, so remove it.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index 71ba8f53f9b7..7e1aabe2b5d8 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -204,7 +204,6 @@ typedef unsigned int kmem_bufctl_t;
  */
 struct slab_rcu {
 	struct rcu_head head;
-	struct kmem_cache *cachep;
 	struct page *page;
 };
 
@@ -1824,7 +1823,7 @@ static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
 static void kmem_rcu_free(struct rcu_head *head)
 {
 	struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
-	struct kmem_cache *cachep = slab_rcu->cachep;
+	struct kmem_cache *cachep = slab_rcu->page->slab_cache;
 
 	kmem_freepages(cachep, slab_rcu->page);
 	if (OFF_SLAB(cachep))
@@ -2052,7 +2051,6 @@ static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
 		struct slab_rcu *slab_rcu;
 
 		slab_rcu = (struct slab_rcu *)slabp;
-		slab_rcu->cachep = cachep;
 		slab_rcu->page = page;
 		call_rcu(&slab_rcu->head, kmem_rcu_free);
 	} else {
-- 
cgit v1.2.3


From 68126702b419fd26ef4946e314bb3a1f57d3a53f Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 24 Oct 2013 10:07:42 +0900
Subject: slab: overloading the RCU head over the LRU for RCU free

With build-time size checking, we can overload the RCU head over the LRU
of struct page to free pages of a slab in rcu context. This really help to
implement to overload the struct slab over the struct page and this
eventually reduce memory usage and cache footprint of the SLAB.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 68 ++++++++++++++++++++++++++++-----------------------------------
 1 file changed, 30 insertions(+), 38 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index 7e1aabe2b5d8..84c4ed62c10d 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -188,25 +188,6 @@ typedef unsigned int kmem_bufctl_t;
 #define	BUFCTL_ACTIVE	(((kmem_bufctl_t)(~0U))-2)
 #define	SLAB_LIMIT	(((kmem_bufctl_t)(~0U))-3)
 
-/*
- * struct slab_rcu
- *
- * slab_destroy on a SLAB_DESTROY_BY_RCU cache uses this structure to
- * arrange for kmem_freepages to be called via RCU.  This is useful if
- * we need to approach a kernel structure obliquely, from its address
- * obtained without the usual locking.  We can lock the structure to
- * stabilize it and check it's still at the given address, only if we
- * can be sure that the memory has not been meanwhile reused for some
- * other kind of object (which our subsystem's lock might corrupt).
- *
- * rcu_read_lock before reading the address, then rcu_read_unlock after
- * taking the spinlock within the structure expected at that address.
- */
-struct slab_rcu {
-	struct rcu_head head;
-	struct page *page;
-};
-
 /*
  * struct slab
  *
@@ -215,14 +196,11 @@ struct slab_rcu {
  * Slabs are chained into three list: fully used, partial, fully free slabs.
  */
 struct slab {
-	union {
-		struct {
-			struct list_head list;
-			void *s_mem;		/* including colour offset */
-			unsigned int inuse;	/* num of objs active in slab */
-			kmem_bufctl_t free;
-		};
-		struct slab_rcu __slab_cover_slab_rcu;
+	struct {
+		struct list_head list;
+		void *s_mem;		/* including colour offset */
+		unsigned int inuse;	/* num of objs active in slab */
+		kmem_bufctl_t free;
 	};
 };
 
@@ -1509,6 +1487,8 @@ void __init kmem_cache_init(void)
 {
 	int i;
 
+	BUILD_BUG_ON(sizeof(((struct page *)NULL)->lru) <
+					sizeof(struct rcu_head));
 	kmem_cache = &kmem_cache_boot;
 	setup_node_pointer(kmem_cache);
 
@@ -1822,12 +1802,13 @@ static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
 
 static void kmem_rcu_free(struct rcu_head *head)
 {
-	struct slab_rcu *slab_rcu = (struct slab_rcu *)head;
-	struct kmem_cache *cachep = slab_rcu->page->slab_cache;
+	struct kmem_cache *cachep;
+	struct page *page;
 
-	kmem_freepages(cachep, slab_rcu->page);
-	if (OFF_SLAB(cachep))
-		kmem_cache_free(cachep->slabp_cache, slab_rcu);
+	page = container_of(head, struct page, rcu_head);
+	cachep = page->slab_cache;
+
+	kmem_freepages(cachep, page);
 }
 
 #if DEBUG
@@ -2048,16 +2029,27 @@ static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
 
 	slab_destroy_debugcheck(cachep, slabp);
 	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
-		struct slab_rcu *slab_rcu;
+		struct rcu_head *head;
+
+		/*
+		 * RCU free overloads the RCU head over the LRU.
+		 * slab_page has been overloeaded over the LRU,
+		 * however it is not used from now on so that
+		 * we can use it safely.
+		 */
+		head = (void *)&page->rcu_head;
+		call_rcu(head, kmem_rcu_free);
 
-		slab_rcu = (struct slab_rcu *)slabp;
-		slab_rcu->page = page;
-		call_rcu(&slab_rcu->head, kmem_rcu_free);
 	} else {
 		kmem_freepages(cachep, page);
-		if (OFF_SLAB(cachep))
-			kmem_cache_free(cachep->slabp_cache, slabp);
 	}
+
+	/*
+	 * From now on, we don't use slab management
+	 * although actual page can be freed in rcu context
+	 */
+	if (OFF_SLAB(cachep))
+		kmem_cache_free(cachep->slabp_cache, slabp);
 }
 
 /**
-- 
cgit v1.2.3


From 56f295ef0dfa7e1d0be18deebe0c15fb6b2d9d5b Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 24 Oct 2013 10:07:43 +0900
Subject: slab: use well-defined macro, virt_to_slab()

This is trivial change, just use well-defined macro.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index 84c4ed62c10d..f9e676edeb0f 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2865,7 +2865,6 @@ static inline void verify_redzone_free(struct kmem_cache *cache, void *obj)
 static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
 				   unsigned long caller)
 {
-	struct page *page;
 	unsigned int objnr;
 	struct slab *slabp;
 
@@ -2873,9 +2872,7 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
 
 	objp -= obj_offset(cachep);
 	kfree_debugcheck(objp);
-	page = virt_to_head_page(objp);
-
-	slabp = page->slab_page;
+	slabp = virt_to_slab(objp);
 
 	if (cachep->flags & SLAB_RED_ZONE) {
 		verify_redzone_free(cachep, objp);
@@ -3087,7 +3084,7 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
 		struct slab *slabp;
 		unsigned objnr;
 
-		slabp = virt_to_head_page(objp)->slab_page;
+		slabp = virt_to_slab(objp);
 		objnr = (unsigned)(objp - slabp->s_mem) / cachep->size;
 		slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
 	}
-- 
cgit v1.2.3


From a57a49887eb3398d31bfaa8009531f7121d6537d Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 24 Oct 2013 10:07:44 +0900
Subject: slab: use __GFP_COMP flag for allocating slab pages

If we use 'struct page' of first page as 'struct slab', there is no
advantage not to use __GFP_COMP. So use __GFP_COMP flag for all the cases.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 43 +++++++++----------------------------------
 1 file changed, 9 insertions(+), 34 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index f9e676edeb0f..75c60821e382 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1718,15 +1718,6 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
 {
 	struct page *page;
 	int nr_pages;
-	int i;
-
-#ifndef CONFIG_MMU
-	/*
-	 * Nommu uses slab's for process anonymous memory allocations, and thus
-	 * requires __GFP_COMP to properly refcount higher order allocations
-	 */
-	flags |= __GFP_COMP;
-#endif
 
 	flags |= cachep->allocflags;
 	if (cachep->flags & SLAB_RECLAIM_ACCOUNT)
@@ -1750,12 +1741,9 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
 	else
 		add_zone_page_state(page_zone(page),
 			NR_SLAB_UNRECLAIMABLE, nr_pages);
-	for (i = 0; i < nr_pages; i++) {
-		__SetPageSlab(page + i);
-
-		if (page->pfmemalloc)
-			SetPageSlabPfmemalloc(page);
-	}
+	__SetPageSlab(page);
+	if (page->pfmemalloc)
+		SetPageSlabPfmemalloc(page);
 	memcg_bind_pages(cachep, cachep->gfporder);
 
 	if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) {
@@ -1775,8 +1763,7 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags,
  */
 static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
 {
-	unsigned long i = (1 << cachep->gfporder);
-	const unsigned long nr_freed = i;
+	const unsigned long nr_freed = (1 << cachep->gfporder);
 
 	kmemcheck_free_shadow(page, cachep->gfporder);
 
@@ -1787,12 +1774,9 @@ static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
 		sub_zone_page_state(page_zone(page),
 				NR_SLAB_UNRECLAIMABLE, nr_freed);
 
+	BUG_ON(!PageSlab(page));
 	__ClearPageSlabPfmemalloc(page);
-	while (i--) {
-		BUG_ON(!PageSlab(page));
-		__ClearPageSlab(page);
-		page++;
-	}
+	__ClearPageSlab(page);
 
 	memcg_release_pages(cachep, cachep->gfporder);
 	if (current->reclaim_state)
@@ -2362,7 +2346,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
 	cachep->colour = left_over / cachep->colour_off;
 	cachep->slab_size = slab_size;
 	cachep->flags = flags;
-	cachep->allocflags = 0;
+	cachep->allocflags = __GFP_COMP;
 	if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
 		cachep->allocflags |= GFP_DMA;
 	cachep->size = size;
@@ -2729,17 +2713,8 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
 static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
 			   struct page *page)
 {
-	int nr_pages;
-
-	nr_pages = 1;
-	if (likely(!PageCompound(page)))
-		nr_pages <<= cache->gfporder;
-
-	do {
-		page->slab_cache = cache;
-		page->slab_page = slab;
-		page++;
-	} while (--nr_pages);
+	page->slab_cache = cache;
+	page->slab_page = slab;
 }
 
 /*
-- 
cgit v1.2.3


From b1cb0982bdd6f57fed690f796659733350bb2cae Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 24 Oct 2013 10:07:45 +0900
Subject: slab: change the management method of free objects of the slab

Current free objects management method of the slab is weird, because
it touch random position of the array of kmem_bufctl_t when we try to
get free object. See following example.

struct slab's free = 6
kmem_bufctl_t array: 1 END 5 7 0 4 3 2

To get free objects, we access this array with following pattern.
6 -> 3 -> 7 -> 2 -> 5 -> 4 -> 0 -> 1 -> END

If we have many objects, this array would be larger and be not in the same
cache line. It is not good for performance.

We can do same thing through more easy way, like as the stack.
Only thing we have to do is to maintain stack top to free object. I use
free field of struct slab for this purpose. After that, if we need to get
an object, we can get it at stack top and manipulate top pointer.
That's all. This method already used in array_cache management.
Following is an access pattern when we use this method.

struct slab's free = 0
kmem_bufctl_t array: 6 3 7 2 5 4 0 1

To get free objects, we access this array with following pattern.
0 -> 1 -> 2 -> 3 -> 4 -> 5 -> 6 -> 7

This may help cache line footprint if slab has many objects, and,
in addition, this makes code much much simpler.

Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 94 ++++++++++++++++++++-------------------------------------------
 1 file changed, 30 insertions(+), 64 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index 75c60821e382..05fe37eb4a57 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -183,9 +183,6 @@ static bool pfmemalloc_active __read_mostly;
  */
 
 typedef unsigned int kmem_bufctl_t;
-#define BUFCTL_END	(((kmem_bufctl_t)(~0U))-0)
-#define BUFCTL_FREE	(((kmem_bufctl_t)(~0U))-1)
-#define	BUFCTL_ACTIVE	(((kmem_bufctl_t)(~0U))-2)
 #define	SLAB_LIMIT	(((kmem_bufctl_t)(~0U))-3)
 
 /*
@@ -2653,9 +2650,8 @@ static void cache_init_objs(struct kmem_cache *cachep,
 		if (cachep->ctor)
 			cachep->ctor(objp);
 #endif
-		slab_bufctl(slabp)[i] = i + 1;
+		slab_bufctl(slabp)[i] = i;
 	}
-	slab_bufctl(slabp)[i - 1] = BUFCTL_END;
 }
 
 static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
@@ -2671,16 +2667,14 @@ static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
 static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
 				int nodeid)
 {
-	void *objp = index_to_obj(cachep, slabp, slabp->free);
-	kmem_bufctl_t next;
+	void *objp;
 
 	slabp->inuse++;
-	next = slab_bufctl(slabp)[slabp->free];
+	objp = index_to_obj(cachep, slabp, slab_bufctl(slabp)[slabp->free]);
 #if DEBUG
-	slab_bufctl(slabp)[slabp->free] = BUFCTL_FREE;
 	WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
 #endif
-	slabp->free = next;
+	slabp->free++;
 
 	return objp;
 }
@@ -2689,19 +2683,23 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
 				void *objp, int nodeid)
 {
 	unsigned int objnr = obj_to_index(cachep, slabp, objp);
-
 #if DEBUG
+	kmem_bufctl_t i;
+
 	/* Verify that the slab belongs to the intended node */
 	WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
 
-	if (slab_bufctl(slabp)[objnr] + 1 <= SLAB_LIMIT + 1) {
-		printk(KERN_ERR "slab: double free detected in cache "
-				"'%s', objp %p\n", cachep->name, objp);
-		BUG();
+	/* Verify double free bug */
+	for (i = slabp->free; i < cachep->num; i++) {
+		if (slab_bufctl(slabp)[i] == objnr) {
+			printk(KERN_ERR "slab: double free detected in cache "
+					"'%s', objp %p\n", cachep->name, objp);
+			BUG();
+		}
 	}
 #endif
-	slab_bufctl(slabp)[objnr] = slabp->free;
-	slabp->free = objnr;
+	slabp->free--;
+	slab_bufctl(slabp)[slabp->free] = objnr;
 	slabp->inuse--;
 }
 
@@ -2862,9 +2860,6 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
 	BUG_ON(objnr >= cachep->num);
 	BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
 
-#ifdef CONFIG_DEBUG_SLAB_LEAK
-	slab_bufctl(slabp)[objnr] = BUFCTL_FREE;
-#endif
 	if (cachep->flags & SLAB_POISON) {
 #ifdef CONFIG_DEBUG_PAGEALLOC
 		if ((cachep->size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
@@ -2881,33 +2876,9 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
 	return objp;
 }
 
-static void check_slabp(struct kmem_cache *cachep, struct slab *slabp)
-{
-	kmem_bufctl_t i;
-	int entries = 0;
-
-	/* Check slab's freelist to see if this obj is there. */
-	for (i = slabp->free; i != BUFCTL_END; i = slab_bufctl(slabp)[i]) {
-		entries++;
-		if (entries > cachep->num || i >= cachep->num)
-			goto bad;
-	}
-	if (entries != cachep->num - slabp->inuse) {
-bad:
-		printk(KERN_ERR "slab: Internal list corruption detected in "
-			"cache '%s'(%d), slabp %p(%d). Tainted(%s). Hexdump:\n",
-			cachep->name, cachep->num, slabp, slabp->inuse,
-			print_tainted());
-		print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1, slabp,
-			sizeof(*slabp) + cachep->num * sizeof(kmem_bufctl_t),
-			1);
-		BUG();
-	}
-}
 #else
 #define kfree_debugcheck(x) do { } while(0)
 #define cache_free_debugcheck(x,objp,z) (objp)
-#define check_slabp(x,y) do { } while(0)
 #endif
 
 static void *cache_alloc_refill(struct kmem_cache *cachep, gfp_t flags,
@@ -2957,7 +2928,6 @@ retry:
 		}
 
 		slabp = list_entry(entry, struct slab, list);
-		check_slabp(cachep, slabp);
 		check_spinlock_acquired(cachep);
 
 		/*
@@ -2975,11 +2945,10 @@ retry:
 			ac_put_obj(cachep, ac, slab_get_obj(cachep, slabp,
 									node));
 		}
-		check_slabp(cachep, slabp);
 
 		/* move slabp to correct slabp list: */
 		list_del(&slabp->list);
-		if (slabp->free == BUFCTL_END)
+		if (slabp->free == cachep->num)
 			list_add(&slabp->list, &n->slabs_full);
 		else
 			list_add(&slabp->list, &n->slabs_partial);
@@ -3054,16 +3023,6 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
 		*dbg_redzone1(cachep, objp) = RED_ACTIVE;
 		*dbg_redzone2(cachep, objp) = RED_ACTIVE;
 	}
-#ifdef CONFIG_DEBUG_SLAB_LEAK
-	{
-		struct slab *slabp;
-		unsigned objnr;
-
-		slabp = virt_to_slab(objp);
-		objnr = (unsigned)(objp - slabp->s_mem) / cachep->size;
-		slab_bufctl(slabp)[objnr] = BUFCTL_ACTIVE;
-	}
-#endif
 	objp += obj_offset(cachep);
 	if (cachep->ctor && cachep->flags & SLAB_POISON)
 		cachep->ctor(objp);
@@ -3269,7 +3228,6 @@ retry:
 
 	slabp = list_entry(entry, struct slab, list);
 	check_spinlock_acquired_node(cachep, nodeid);
-	check_slabp(cachep, slabp);
 
 	STATS_INC_NODEALLOCS(cachep);
 	STATS_INC_ACTIVE(cachep);
@@ -3278,12 +3236,11 @@ retry:
 	BUG_ON(slabp->inuse == cachep->num);
 
 	obj = slab_get_obj(cachep, slabp, nodeid);
-	check_slabp(cachep, slabp);
 	n->free_objects--;
 	/* move slabp to correct slabp list: */
 	list_del(&slabp->list);
 
-	if (slabp->free == BUFCTL_END)
+	if (slabp->free == cachep->num)
 		list_add(&slabp->list, &n->slabs_full);
 	else
 		list_add(&slabp->list, &n->slabs_partial);
@@ -3445,11 +3402,9 @@ static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
 		n = cachep->node[node];
 		list_del(&slabp->list);
 		check_spinlock_acquired_node(cachep, node);
-		check_slabp(cachep, slabp);
 		slab_put_obj(cachep, slabp, objp, node);
 		STATS_DEC_ACTIVE(cachep);
 		n->free_objects++;
-		check_slabp(cachep, slabp);
 
 		/* fixup slab chains */
 		if (slabp->inuse == 0) {
@@ -4308,12 +4263,23 @@ static inline int add_caller(unsigned long *n, unsigned long v)
 static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s)
 {
 	void *p;
-	int i;
+	int i, j;
+
 	if (n[0] == n[1])
 		return;
 	for (i = 0, p = s->s_mem; i < c->num; i++, p += c->size) {
-		if (slab_bufctl(s)[i] != BUFCTL_ACTIVE)
+		bool active = true;
+
+		for (j = s->free; j < c->num; j++) {
+			/* Skip freed item */
+			if (slab_bufctl(s)[j] == i) {
+				active = false;
+				break;
+			}
+		}
+		if (!active)
 			continue;
+
 		if (!add_caller(n, (unsigned long)*dbg_userword(c, p)))
 			return;
 	}
-- 
cgit v1.2.3


From 16025177e1e16529451108faed257db95c7c9d6a Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 24 Oct 2013 10:07:46 +0900
Subject: slab: remove kmem_bufctl_t

Now, we changed the management method of free objects of the slab and
there is no need to use special value, BUFCTL_END, BUFCTL_FREE and
BUFCTL_ACTIVE. So remove them.

Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 42 +++++++++++-------------------------------
 1 file changed, 11 insertions(+), 31 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index 05fe37eb4a57..6ced1ccf8abb 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -163,27 +163,7 @@
  */
 static bool pfmemalloc_active __read_mostly;
 
-/*
- * kmem_bufctl_t:
- *
- * Bufctl's are used for linking objs within a slab
- * linked offsets.
- *
- * This implementation relies on "struct page" for locating the cache &
- * slab an object belongs to.
- * This allows the bufctl structure to be small (one int), but limits
- * the number of objects a slab (not a cache) can contain when off-slab
- * bufctls are used. The limit is the size of the largest general cache
- * that does not use off-slab slabs.
- * For 32bit archs with 4 kB pages, is this 56.
- * This is not serious, as it is only for large objects, when it is unwise
- * to have too many per slab.
- * Note: This limit can be raised by introducing a general cache whose size
- * is less than 512 (PAGE_SIZE<<3), but greater than 256.
- */
-
-typedef unsigned int kmem_bufctl_t;
-#define	SLAB_LIMIT	(((kmem_bufctl_t)(~0U))-3)
+#define	SLAB_LIMIT	(((unsigned int)(~0U))-1)
 
 /*
  * struct slab
@@ -197,7 +177,7 @@ struct slab {
 		struct list_head list;
 		void *s_mem;		/* including colour offset */
 		unsigned int inuse;	/* num of objs active in slab */
-		kmem_bufctl_t free;
+		unsigned int free;
 	};
 };
 
@@ -613,7 +593,7 @@ static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
 
 static size_t slab_mgmt_size(size_t nr_objs, size_t align)
 {
-	return ALIGN(sizeof(struct slab)+nr_objs*sizeof(kmem_bufctl_t), align);
+	return ALIGN(sizeof(struct slab)+nr_objs*sizeof(unsigned int), align);
 }
 
 /*
@@ -633,7 +613,7 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size,
 	 * slab is used for:
 	 *
 	 * - The struct slab
-	 * - One kmem_bufctl_t for each object
+	 * - One unsigned int for each object
 	 * - Padding to respect alignment of @align
 	 * - @buffer_size bytes for each object
 	 *
@@ -658,7 +638,7 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size,
 		 * into account.
 		 */
 		nr_objs = (slab_size - sizeof(struct slab)) /
-			  (buffer_size + sizeof(kmem_bufctl_t));
+			  (buffer_size + sizeof(unsigned int));
 
 		/*
 		 * This calculated number will be either the right
@@ -2068,7 +2048,7 @@ static size_t calculate_slab_order(struct kmem_cache *cachep,
 			 * looping condition in cache_grow().
 			 */
 			offslab_limit = size - sizeof(struct slab);
-			offslab_limit /= sizeof(kmem_bufctl_t);
+			offslab_limit /= sizeof(unsigned int);
 
  			if (num > offslab_limit)
 				break;
@@ -2309,7 +2289,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
 	if (!cachep->num)
 		return -E2BIG;
 
-	slab_size = ALIGN(cachep->num * sizeof(kmem_bufctl_t)
+	slab_size = ALIGN(cachep->num * sizeof(unsigned int)
 			  + sizeof(struct slab), cachep->align);
 
 	/*
@@ -2324,7 +2304,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
 	if (flags & CFLGS_OFF_SLAB) {
 		/* really off slab. No need for manual alignment */
 		slab_size =
-		    cachep->num * sizeof(kmem_bufctl_t) + sizeof(struct slab);
+		    cachep->num * sizeof(unsigned int) + sizeof(struct slab);
 
 #ifdef CONFIG_PAGE_POISONING
 		/* If we're going to use the generic kernel_map_pages()
@@ -2603,9 +2583,9 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep,
 	return slabp;
 }
 
-static inline kmem_bufctl_t *slab_bufctl(struct slab *slabp)
+static inline unsigned int *slab_bufctl(struct slab *slabp)
 {
-	return (kmem_bufctl_t *) (slabp + 1);
+	return (unsigned int *) (slabp + 1);
 }
 
 static void cache_init_objs(struct kmem_cache *cachep,
@@ -2684,7 +2664,7 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
 {
 	unsigned int objnr = obj_to_index(cachep, slabp, objp);
 #if DEBUG
-	kmem_bufctl_t i;
+	unsigned int i;
 
 	/* Verify that the slab belongs to the intended node */
 	WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
-- 
cgit v1.2.3


From 45eed508de6cec3174040f800aaf90d60c7b5b5b Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 24 Oct 2013 10:07:47 +0900
Subject: slab: remove SLAB_LIMIT

It's useless now, so remove it.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 7 -------
 1 file changed, 7 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index 6ced1ccf8abb..c271d5b71093 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -163,8 +163,6 @@
  */
 static bool pfmemalloc_active __read_mostly;
 
-#define	SLAB_LIMIT	(((unsigned int)(~0U))-1)
-
 /*
  * struct slab
  *
@@ -626,8 +624,6 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size,
 		mgmt_size = 0;
 		nr_objs = slab_size / buffer_size;
 
-		if (nr_objs > SLAB_LIMIT)
-			nr_objs = SLAB_LIMIT;
 	} else {
 		/*
 		 * Ignore padding for the initial guess. The padding
@@ -648,9 +644,6 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size,
 		       > slab_size)
 			nr_objs--;
 
-		if (nr_objs > SLAB_LIMIT)
-			nr_objs = SLAB_LIMIT;
-
 		mgmt_size = slab_mgmt_size(nr_objs, align);
 	}
 	*num = nr_objs;
-- 
cgit v1.2.3


From 106a74e13b329cf609c145dc198087c04f5f8ca5 Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 24 Oct 2013 10:07:48 +0900
Subject: slab: replace free and inuse in struct slab with newly introduced
 active

Now, free in struct slab is same meaning as inuse.
So, remove both and replace them with active.

Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 54 +++++++++++++++++++++++++-----------------------------
 1 file changed, 25 insertions(+), 29 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index c271d5b71093..2ec2336a1ffc 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -174,8 +174,7 @@ struct slab {
 	struct {
 		struct list_head list;
 		void *s_mem;		/* including colour offset */
-		unsigned int inuse;	/* num of objs active in slab */
-		unsigned int free;
+		unsigned int active;	/* num of objs active in slab */
 	};
 };
 
@@ -1658,7 +1657,7 @@ slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid)
 			active_slabs++;
 		}
 		list_for_each_entry(slabp, &n->slabs_partial, list) {
-			active_objs += slabp->inuse;
+			active_objs += slabp->active;
 			active_slabs++;
 		}
 		list_for_each_entry(slabp, &n->slabs_free, list)
@@ -2451,7 +2450,7 @@ static int drain_freelist(struct kmem_cache *cache,
 
 		slabp = list_entry(p, struct slab, list);
 #if DEBUG
-		BUG_ON(slabp->inuse);
+		BUG_ON(slabp->active);
 #endif
 		list_del(&slabp->list);
 		/*
@@ -2570,9 +2569,8 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep,
 		slabp = addr + colour_off;
 		colour_off += cachep->slab_size;
 	}
-	slabp->inuse = 0;
+	slabp->active = 0;
 	slabp->s_mem = addr + colour_off;
-	slabp->free = 0;
 	return slabp;
 }
 
@@ -2642,12 +2640,11 @@ static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
 {
 	void *objp;
 
-	slabp->inuse++;
-	objp = index_to_obj(cachep, slabp, slab_bufctl(slabp)[slabp->free]);
+	objp = index_to_obj(cachep, slabp, slab_bufctl(slabp)[slabp->active]);
+	slabp->active++;
 #if DEBUG
 	WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
 #endif
-	slabp->free++;
 
 	return objp;
 }
@@ -2663,7 +2660,7 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
 	WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
 
 	/* Verify double free bug */
-	for (i = slabp->free; i < cachep->num; i++) {
+	for (i = slabp->active; i < cachep->num; i++) {
 		if (slab_bufctl(slabp)[i] == objnr) {
 			printk(KERN_ERR "slab: double free detected in cache "
 					"'%s', objp %p\n", cachep->name, objp);
@@ -2671,9 +2668,8 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
 		}
 	}
 #endif
-	slabp->free--;
-	slab_bufctl(slabp)[slabp->free] = objnr;
-	slabp->inuse--;
+	slabp->active--;
+	slab_bufctl(slabp)[slabp->active] = objnr;
 }
 
 /*
@@ -2908,9 +2904,9 @@ retry:
 		 * there must be at least one object available for
 		 * allocation.
 		 */
-		BUG_ON(slabp->inuse >= cachep->num);
+		BUG_ON(slabp->active >= cachep->num);
 
-		while (slabp->inuse < cachep->num && batchcount--) {
+		while (slabp->active < cachep->num && batchcount--) {
 			STATS_INC_ALLOCED(cachep);
 			STATS_INC_ACTIVE(cachep);
 			STATS_SET_HIGH(cachep);
@@ -2921,7 +2917,7 @@ retry:
 
 		/* move slabp to correct slabp list: */
 		list_del(&slabp->list);
-		if (slabp->free == cachep->num)
+		if (slabp->active == cachep->num)
 			list_add(&slabp->list, &n->slabs_full);
 		else
 			list_add(&slabp->list, &n->slabs_partial);
@@ -3206,14 +3202,14 @@ retry:
 	STATS_INC_ACTIVE(cachep);
 	STATS_SET_HIGH(cachep);
 
-	BUG_ON(slabp->inuse == cachep->num);
+	BUG_ON(slabp->active == cachep->num);
 
 	obj = slab_get_obj(cachep, slabp, nodeid);
 	n->free_objects--;
 	/* move slabp to correct slabp list: */
 	list_del(&slabp->list);
 
-	if (slabp->free == cachep->num)
+	if (slabp->active == cachep->num)
 		list_add(&slabp->list, &n->slabs_full);
 	else
 		list_add(&slabp->list, &n->slabs_partial);
@@ -3380,7 +3376,7 @@ static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
 		n->free_objects++;
 
 		/* fixup slab chains */
-		if (slabp->inuse == 0) {
+		if (slabp->active == 0) {
 			if (n->free_objects > n->free_limit) {
 				n->free_objects -= cachep->num;
 				/* No need to drop any previously held
@@ -3441,7 +3437,7 @@ free_done:
 			struct slab *slabp;
 
 			slabp = list_entry(p, struct slab, list);
-			BUG_ON(slabp->inuse);
+			BUG_ON(slabp->active);
 
 			i++;
 			p = p->next;
@@ -4066,22 +4062,22 @@ void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo)
 		spin_lock_irq(&n->list_lock);
 
 		list_for_each_entry(slabp, &n->slabs_full, list) {
-			if (slabp->inuse != cachep->num && !error)
+			if (slabp->active != cachep->num && !error)
 				error = "slabs_full accounting error";
 			active_objs += cachep->num;
 			active_slabs++;
 		}
 		list_for_each_entry(slabp, &n->slabs_partial, list) {
-			if (slabp->inuse == cachep->num && !error)
-				error = "slabs_partial inuse accounting error";
-			if (!slabp->inuse && !error)
-				error = "slabs_partial/inuse accounting error";
-			active_objs += slabp->inuse;
+			if (slabp->active == cachep->num && !error)
+				error = "slabs_partial accounting error";
+			if (!slabp->active && !error)
+				error = "slabs_partial accounting error";
+			active_objs += slabp->active;
 			active_slabs++;
 		}
 		list_for_each_entry(slabp, &n->slabs_free, list) {
-			if (slabp->inuse && !error)
-				error = "slabs_free/inuse accounting error";
+			if (slabp->active && !error)
+				error = "slabs_free accounting error";
 			num_slabs++;
 		}
 		free_objects += n->free_objects;
@@ -4243,7 +4239,7 @@ static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s)
 	for (i = 0, p = s->s_mem; i < c->num; i++, p += c->size) {
 		bool active = true;
 
-		for (j = s->free; j < c->num; j++) {
+		for (j = s->active; j < c->num; j++) {
 			/* Skip freed item */
 			if (slab_bufctl(s)[j] == i) {
 				active = false;
-- 
cgit v1.2.3


From 8456a648cf44f14365f1f44de90a3da2526a4776 Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 24 Oct 2013 10:07:49 +0900
Subject: slab: use struct page for slab management

Now, there are a few field in struct slab, so we can overload these
over struct page. This will save some memory and reduce cache footprint.

After this change, slabp_cache and slab_size no longer related to
a struct slab, so rename them as freelist_cache and freelist_size.

These changes are just mechanical ones and there is no functional change.

Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 306 +++++++++++++++++++++++++++++---------------------------------
 1 file changed, 143 insertions(+), 163 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index 2ec2336a1ffc..0e7f2e73e08e 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -163,21 +163,6 @@
  */
 static bool pfmemalloc_active __read_mostly;
 
-/*
- * struct slab
- *
- * Manages the objs in a slab. Placed either at the beginning of mem allocated
- * for a slab, or allocated from an general cache.
- * Slabs are chained into three list: fully used, partial, fully free slabs.
- */
-struct slab {
-	struct {
-		struct list_head list;
-		void *s_mem;		/* including colour offset */
-		unsigned int active;	/* num of objs active in slab */
-	};
-};
-
 /*
  * struct array_cache
  *
@@ -405,18 +390,10 @@ static inline struct kmem_cache *virt_to_cache(const void *obj)
 	return page->slab_cache;
 }
 
-static inline struct slab *virt_to_slab(const void *obj)
-{
-	struct page *page = virt_to_head_page(obj);
-
-	VM_BUG_ON(!PageSlab(page));
-	return page->slab_page;
-}
-
-static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab,
+static inline void *index_to_obj(struct kmem_cache *cache, struct page *page,
 				 unsigned int idx)
 {
-	return slab->s_mem + cache->size * idx;
+	return page->s_mem + cache->size * idx;
 }
 
 /*
@@ -426,9 +403,9 @@ static inline void *index_to_obj(struct kmem_cache *cache, struct slab *slab,
  *   reciprocal_divide(offset, cache->reciprocal_buffer_size)
  */
 static inline unsigned int obj_to_index(const struct kmem_cache *cache,
-					const struct slab *slab, void *obj)
+					const struct page *page, void *obj)
 {
-	u32 offset = (obj - slab->s_mem);
+	u32 offset = (obj - page->s_mem);
 	return reciprocal_divide(offset, cache->reciprocal_buffer_size);
 }
 
@@ -590,7 +567,7 @@ static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
 
 static size_t slab_mgmt_size(size_t nr_objs, size_t align)
 {
-	return ALIGN(sizeof(struct slab)+nr_objs*sizeof(unsigned int), align);
+	return ALIGN(nr_objs * sizeof(unsigned int), align);
 }
 
 /*
@@ -609,7 +586,6 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size,
 	 * on it. For the latter case, the memory allocated for a
 	 * slab is used for:
 	 *
-	 * - The struct slab
 	 * - One unsigned int for each object
 	 * - Padding to respect alignment of @align
 	 * - @buffer_size bytes for each object
@@ -632,8 +608,7 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size,
 		 * into the memory allocation when taking the padding
 		 * into account.
 		 */
-		nr_objs = (slab_size - sizeof(struct slab)) /
-			  (buffer_size + sizeof(unsigned int));
+		nr_objs = (slab_size) / (buffer_size + sizeof(unsigned int));
 
 		/*
 		 * This calculated number will be either the right
@@ -773,11 +748,11 @@ static struct array_cache *alloc_arraycache(int node, int entries,
 	return nc;
 }
 
-static inline bool is_slab_pfmemalloc(struct slab *slabp)
+static inline bool is_slab_pfmemalloc(struct page *page)
 {
-	struct page *page = virt_to_page(slabp->s_mem);
+	struct page *mem_page = virt_to_page(page->s_mem);
 
-	return PageSlabPfmemalloc(page);
+	return PageSlabPfmemalloc(mem_page);
 }
 
 /* Clears pfmemalloc_active if no slabs have pfmalloc set */
@@ -785,23 +760,23 @@ static void recheck_pfmemalloc_active(struct kmem_cache *cachep,
 						struct array_cache *ac)
 {
 	struct kmem_cache_node *n = cachep->node[numa_mem_id()];
-	struct slab *slabp;
+	struct page *page;
 	unsigned long flags;
 
 	if (!pfmemalloc_active)
 		return;
 
 	spin_lock_irqsave(&n->list_lock, flags);
-	list_for_each_entry(slabp, &n->slabs_full, list)
-		if (is_slab_pfmemalloc(slabp))
+	list_for_each_entry(page, &n->slabs_full, lru)
+		if (is_slab_pfmemalloc(page))
 			goto out;
 
-	list_for_each_entry(slabp, &n->slabs_partial, list)
-		if (is_slab_pfmemalloc(slabp))
+	list_for_each_entry(page, &n->slabs_partial, lru)
+		if (is_slab_pfmemalloc(page))
 			goto out;
 
-	list_for_each_entry(slabp, &n->slabs_free, list)
-		if (is_slab_pfmemalloc(slabp))
+	list_for_each_entry(page, &n->slabs_free, lru)
+		if (is_slab_pfmemalloc(page))
 			goto out;
 
 	pfmemalloc_active = false;
@@ -841,8 +816,8 @@ static void *__ac_get_obj(struct kmem_cache *cachep, struct array_cache *ac,
 		 */
 		n = cachep->node[numa_mem_id()];
 		if (!list_empty(&n->slabs_free) && force_refill) {
-			struct slab *slabp = virt_to_slab(objp);
-			ClearPageSlabPfmemalloc(virt_to_head_page(slabp->s_mem));
+			struct page *page = virt_to_head_page(objp);
+			ClearPageSlabPfmemalloc(virt_to_head_page(page->s_mem));
 			clear_obj_pfmemalloc(&objp);
 			recheck_pfmemalloc_active(cachep, ac);
 			return objp;
@@ -874,9 +849,9 @@ static void *__ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac,
 {
 	if (unlikely(pfmemalloc_active)) {
 		/* Some pfmemalloc slabs exist, check if this is one */
-		struct slab *slabp = virt_to_slab(objp);
-		struct page *page = virt_to_head_page(slabp->s_mem);
-		if (PageSlabPfmemalloc(page))
+		struct page *page = virt_to_head_page(objp);
+		struct page *mem_page = virt_to_head_page(page->s_mem);
+		if (PageSlabPfmemalloc(mem_page))
 			set_obj_pfmemalloc(&objp);
 	}
 
@@ -1633,7 +1608,7 @@ static noinline void
 slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid)
 {
 	struct kmem_cache_node *n;
-	struct slab *slabp;
+	struct page *page;
 	unsigned long flags;
 	int node;
 
@@ -1652,15 +1627,15 @@ slab_out_of_memory(struct kmem_cache *cachep, gfp_t gfpflags, int nodeid)
 			continue;
 
 		spin_lock_irqsave(&n->list_lock, flags);
-		list_for_each_entry(slabp, &n->slabs_full, list) {
+		list_for_each_entry(page, &n->slabs_full, lru) {
 			active_objs += cachep->num;
 			active_slabs++;
 		}
-		list_for_each_entry(slabp, &n->slabs_partial, list) {
-			active_objs += slabp->active;
+		list_for_each_entry(page, &n->slabs_partial, lru) {
+			active_objs += page->active;
 			active_slabs++;
 		}
-		list_for_each_entry(slabp, &n->slabs_free, list)
+		list_for_each_entry(page, &n->slabs_free, lru)
 			num_slabs++;
 
 		free_objects += n->free_objects;
@@ -1746,6 +1721,8 @@ static void kmem_freepages(struct kmem_cache *cachep, struct page *page)
 	BUG_ON(!PageSlab(page));
 	__ClearPageSlabPfmemalloc(page);
 	__ClearPageSlab(page);
+	page_mapcount_reset(page);
+	page->mapping = NULL;
 
 	memcg_release_pages(cachep, cachep->gfporder);
 	if (current->reclaim_state)
@@ -1910,19 +1887,19 @@ static void check_poison_obj(struct kmem_cache *cachep, void *objp)
 		/* Print some data about the neighboring objects, if they
 		 * exist:
 		 */
-		struct slab *slabp = virt_to_slab(objp);
+		struct page *page = virt_to_head_page(objp);
 		unsigned int objnr;
 
-		objnr = obj_to_index(cachep, slabp, objp);
+		objnr = obj_to_index(cachep, page, objp);
 		if (objnr) {
-			objp = index_to_obj(cachep, slabp, objnr - 1);
+			objp = index_to_obj(cachep, page, objnr - 1);
 			realobj = (char *)objp + obj_offset(cachep);
 			printk(KERN_ERR "Prev obj: start=%p, len=%d\n",
 			       realobj, size);
 			print_objinfo(cachep, objp, 2);
 		}
 		if (objnr + 1 < cachep->num) {
-			objp = index_to_obj(cachep, slabp, objnr + 1);
+			objp = index_to_obj(cachep, page, objnr + 1);
 			realobj = (char *)objp + obj_offset(cachep);
 			printk(KERN_ERR "Next obj: start=%p, len=%d\n",
 			       realobj, size);
@@ -1933,11 +1910,12 @@ static void check_poison_obj(struct kmem_cache *cachep, void *objp)
 #endif
 
 #if DEBUG
-static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp)
+static void slab_destroy_debugcheck(struct kmem_cache *cachep,
+						struct page *page)
 {
 	int i;
 	for (i = 0; i < cachep->num; i++) {
-		void *objp = index_to_obj(cachep, slabp, i);
+		void *objp = index_to_obj(cachep, page, i);
 
 		if (cachep->flags & SLAB_POISON) {
 #ifdef CONFIG_DEBUG_PAGEALLOC
@@ -1962,7 +1940,8 @@ static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slab
 	}
 }
 #else
-static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slabp)
+static void slab_destroy_debugcheck(struct kmem_cache *cachep,
+						struct page *page)
 {
 }
 #endif
@@ -1976,11 +1955,12 @@ static void slab_destroy_debugcheck(struct kmem_cache *cachep, struct slab *slab
  * Before calling the slab must have been unlinked from the cache.  The
  * cache-lock is not held/needed.
  */
-static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
+static void slab_destroy(struct kmem_cache *cachep, struct page *page)
 {
-	struct page *page = virt_to_head_page(slabp->s_mem);
+	struct freelist *freelist;
 
-	slab_destroy_debugcheck(cachep, slabp);
+	freelist = page->freelist;
+	slab_destroy_debugcheck(cachep, page);
 	if (unlikely(cachep->flags & SLAB_DESTROY_BY_RCU)) {
 		struct rcu_head *head;
 
@@ -1998,11 +1978,11 @@ static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
 	}
 
 	/*
-	 * From now on, we don't use slab management
+	 * From now on, we don't use freelist
 	 * although actual page can be freed in rcu context
 	 */
 	if (OFF_SLAB(cachep))
-		kmem_cache_free(cachep->slabp_cache, slabp);
+		kmem_cache_free(cachep->freelist_cache, freelist);
 }
 
 /**
@@ -2039,7 +2019,7 @@ static size_t calculate_slab_order(struct kmem_cache *cachep,
 			 * use off-slab slabs. Needed to avoid a possible
 			 * looping condition in cache_grow().
 			 */
-			offslab_limit = size - sizeof(struct slab);
+			offslab_limit = size;
 			offslab_limit /= sizeof(unsigned int);
 
  			if (num > offslab_limit)
@@ -2162,7 +2142,7 @@ static int __init_refok setup_cpu_cache(struct kmem_cache *cachep, gfp_t gfp)
 int
 __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
 {
-	size_t left_over, slab_size, ralign;
+	size_t left_over, freelist_size, ralign;
 	gfp_t gfp;
 	int err;
 	size_t size = cachep->size;
@@ -2281,22 +2261,21 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
 	if (!cachep->num)
 		return -E2BIG;
 
-	slab_size = ALIGN(cachep->num * sizeof(unsigned int)
-			  + sizeof(struct slab), cachep->align);
+	freelist_size =
+		ALIGN(cachep->num * sizeof(unsigned int), cachep->align);
 
 	/*
 	 * If the slab has been placed off-slab, and we have enough space then
 	 * move it on-slab. This is at the expense of any extra colouring.
 	 */
-	if (flags & CFLGS_OFF_SLAB && left_over >= slab_size) {
+	if (flags & CFLGS_OFF_SLAB && left_over >= freelist_size) {
 		flags &= ~CFLGS_OFF_SLAB;
-		left_over -= slab_size;
+		left_over -= freelist_size;
 	}
 
 	if (flags & CFLGS_OFF_SLAB) {
 		/* really off slab. No need for manual alignment */
-		slab_size =
-		    cachep->num * sizeof(unsigned int) + sizeof(struct slab);
+		freelist_size = cachep->num * sizeof(unsigned int);
 
 #ifdef CONFIG_PAGE_POISONING
 		/* If we're going to use the generic kernel_map_pages()
@@ -2313,7 +2292,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
 	if (cachep->colour_off < cachep->align)
 		cachep->colour_off = cachep->align;
 	cachep->colour = left_over / cachep->colour_off;
-	cachep->slab_size = slab_size;
+	cachep->freelist_size = freelist_size;
 	cachep->flags = flags;
 	cachep->allocflags = __GFP_COMP;
 	if (CONFIG_ZONE_DMA_FLAG && (flags & SLAB_CACHE_DMA))
@@ -2322,7 +2301,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
 	cachep->reciprocal_buffer_size = reciprocal_value(size);
 
 	if (flags & CFLGS_OFF_SLAB) {
-		cachep->slabp_cache = kmalloc_slab(slab_size, 0u);
+		cachep->freelist_cache = kmalloc_slab(freelist_size, 0u);
 		/*
 		 * This is a possibility for one of the malloc_sizes caches.
 		 * But since we go off slab only for object size greater than
@@ -2330,7 +2309,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
 		 * this should not happen at all.
 		 * But leave a BUG_ON for some lucky dude.
 		 */
-		BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache));
+		BUG_ON(ZERO_OR_NULL_PTR(cachep->freelist_cache));
 	}
 
 	err = setup_cpu_cache(cachep, gfp);
@@ -2436,7 +2415,7 @@ static int drain_freelist(struct kmem_cache *cache,
 {
 	struct list_head *p;
 	int nr_freed;
-	struct slab *slabp;
+	struct page *page;
 
 	nr_freed = 0;
 	while (nr_freed < tofree && !list_empty(&n->slabs_free)) {
@@ -2448,18 +2427,18 @@ static int drain_freelist(struct kmem_cache *cache,
 			goto out;
 		}
 
-		slabp = list_entry(p, struct slab, list);
+		page = list_entry(p, struct page, lru);
 #if DEBUG
-		BUG_ON(slabp->active);
+		BUG_ON(page->active);
 #endif
-		list_del(&slabp->list);
+		list_del(&page->lru);
 		/*
 		 * Safe to drop the lock. The slab is no longer linked
 		 * to the cache.
 		 */
 		n->free_objects -= cache->num;
 		spin_unlock_irq(&n->list_lock);
-		slab_destroy(cache, slabp);
+		slab_destroy(cache, page);
 		nr_freed++;
 	}
 out:
@@ -2542,18 +2521,18 @@ int __kmem_cache_shutdown(struct kmem_cache *cachep)
  * descriptors in kmem_cache_create, we search through the malloc_sizes array.
  * If we are creating a malloc_sizes cache here it would not be visible to
  * kmem_find_general_cachep till the initialization is complete.
- * Hence we cannot have slabp_cache same as the original cache.
+ * Hence we cannot have freelist_cache same as the original cache.
  */
-static struct slab *alloc_slabmgmt(struct kmem_cache *cachep,
+static struct freelist *alloc_slabmgmt(struct kmem_cache *cachep,
 				   struct page *page, int colour_off,
 				   gfp_t local_flags, int nodeid)
 {
-	struct slab *slabp;
+	struct freelist *freelist;
 	void *addr = page_address(page);
 
 	if (OFF_SLAB(cachep)) {
 		/* Slab management obj is off-slab. */
-		slabp = kmem_cache_alloc_node(cachep->slabp_cache,
+		freelist = kmem_cache_alloc_node(cachep->freelist_cache,
 					      local_flags, nodeid);
 		/*
 		 * If the first object in the slab is leaked (it's allocated
@@ -2561,31 +2540,31 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep,
 		 * kmemleak does not treat the ->s_mem pointer as a reference
 		 * to the object. Otherwise we will not report the leak.
 		 */
-		kmemleak_scan_area(&slabp->list, sizeof(struct list_head),
+		kmemleak_scan_area(&page->lru, sizeof(struct list_head),
 				   local_flags);
-		if (!slabp)
+		if (!freelist)
 			return NULL;
 	} else {
-		slabp = addr + colour_off;
-		colour_off += cachep->slab_size;
+		freelist = addr + colour_off;
+		colour_off += cachep->freelist_size;
 	}
-	slabp->active = 0;
-	slabp->s_mem = addr + colour_off;
-	return slabp;
+	page->active = 0;
+	page->s_mem = addr + colour_off;
+	return freelist;
 }
 
-static inline unsigned int *slab_bufctl(struct slab *slabp)
+static inline unsigned int *slab_bufctl(struct page *page)
 {
-	return (unsigned int *) (slabp + 1);
+	return (unsigned int *)(page->freelist);
 }
 
 static void cache_init_objs(struct kmem_cache *cachep,
-			    struct slab *slabp)
+			    struct page *page)
 {
 	int i;
 
 	for (i = 0; i < cachep->num; i++) {
-		void *objp = index_to_obj(cachep, slabp, i);
+		void *objp = index_to_obj(cachep, page, i);
 #if DEBUG
 		/* need to poison the objs? */
 		if (cachep->flags & SLAB_POISON)
@@ -2621,7 +2600,7 @@ static void cache_init_objs(struct kmem_cache *cachep,
 		if (cachep->ctor)
 			cachep->ctor(objp);
 #endif
-		slab_bufctl(slabp)[i] = i;
+		slab_bufctl(page)[i] = i;
 	}
 }
 
@@ -2635,13 +2614,13 @@ static void kmem_flagcheck(struct kmem_cache *cachep, gfp_t flags)
 	}
 }
 
-static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
+static void *slab_get_obj(struct kmem_cache *cachep, struct page *page,
 				int nodeid)
 {
 	void *objp;
 
-	objp = index_to_obj(cachep, slabp, slab_bufctl(slabp)[slabp->active]);
-	slabp->active++;
+	objp = index_to_obj(cachep, page, slab_bufctl(page)[page->active]);
+	page->active++;
 #if DEBUG
 	WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
 #endif
@@ -2649,10 +2628,10 @@ static void *slab_get_obj(struct kmem_cache *cachep, struct slab *slabp,
 	return objp;
 }
 
-static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
+static void slab_put_obj(struct kmem_cache *cachep, struct page *page,
 				void *objp, int nodeid)
 {
-	unsigned int objnr = obj_to_index(cachep, slabp, objp);
+	unsigned int objnr = obj_to_index(cachep, page, objp);
 #if DEBUG
 	unsigned int i;
 
@@ -2660,16 +2639,16 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
 	WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
 
 	/* Verify double free bug */
-	for (i = slabp->active; i < cachep->num; i++) {
-		if (slab_bufctl(slabp)[i] == objnr) {
+	for (i = page->active; i < cachep->num; i++) {
+		if (slab_bufctl(page)[i] == objnr) {
 			printk(KERN_ERR "slab: double free detected in cache "
 					"'%s', objp %p\n", cachep->name, objp);
 			BUG();
 		}
 	}
 #endif
-	slabp->active--;
-	slab_bufctl(slabp)[slabp->active] = objnr;
+	page->active--;
+	slab_bufctl(page)[page->active] = objnr;
 }
 
 /*
@@ -2677,11 +2656,11 @@ static void slab_put_obj(struct kmem_cache *cachep, struct slab *slabp,
  * for the slab allocator to be able to lookup the cache and slab of a
  * virtual address for kfree, ksize, and slab debugging.
  */
-static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
-			   struct page *page)
+static void slab_map_pages(struct kmem_cache *cache, struct page *page,
+			   struct freelist *freelist)
 {
 	page->slab_cache = cache;
-	page->slab_page = slab;
+	page->freelist = freelist;
 }
 
 /*
@@ -2691,7 +2670,7 @@ static void slab_map_pages(struct kmem_cache *cache, struct slab *slab,
 static int cache_grow(struct kmem_cache *cachep,
 		gfp_t flags, int nodeid, struct page *page)
 {
-	struct slab *slabp;
+	struct freelist *freelist;
 	size_t offset;
 	gfp_t local_flags;
 	struct kmem_cache_node *n;
@@ -2738,14 +2717,14 @@ static int cache_grow(struct kmem_cache *cachep,
 		goto failed;
 
 	/* Get slab management. */
-	slabp = alloc_slabmgmt(cachep, page, offset,
+	freelist = alloc_slabmgmt(cachep, page, offset,
 			local_flags & ~GFP_CONSTRAINT_MASK, nodeid);
-	if (!slabp)
+	if (!freelist)
 		goto opps1;
 
-	slab_map_pages(cachep, slabp, page);
+	slab_map_pages(cachep, page, freelist);
 
-	cache_init_objs(cachep, slabp);
+	cache_init_objs(cachep, page);
 
 	if (local_flags & __GFP_WAIT)
 		local_irq_disable();
@@ -2753,7 +2732,7 @@ static int cache_grow(struct kmem_cache *cachep,
 	spin_lock(&n->list_lock);
 
 	/* Make slab active. */
-	list_add_tail(&slabp->list, &(n->slabs_free));
+	list_add_tail(&page->lru, &(n->slabs_free));
 	STATS_INC_GROWN(cachep);
 	n->free_objects += cachep->num;
 	spin_unlock(&n->list_lock);
@@ -2808,13 +2787,13 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
 				   unsigned long caller)
 {
 	unsigned int objnr;
-	struct slab *slabp;
+	struct page *page;
 
 	BUG_ON(virt_to_cache(objp) != cachep);
 
 	objp -= obj_offset(cachep);
 	kfree_debugcheck(objp);
-	slabp = virt_to_slab(objp);
+	page = virt_to_head_page(objp);
 
 	if (cachep->flags & SLAB_RED_ZONE) {
 		verify_redzone_free(cachep, objp);
@@ -2824,10 +2803,10 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
 	if (cachep->flags & SLAB_STORE_USER)
 		*dbg_userword(cachep, objp) = (void *)caller;
 
-	objnr = obj_to_index(cachep, slabp, objp);
+	objnr = obj_to_index(cachep, page, objp);
 
 	BUG_ON(objnr >= cachep->num);
-	BUG_ON(objp != index_to_obj(cachep, slabp, objnr));
+	BUG_ON(objp != index_to_obj(cachep, page, objnr));
 
 	if (cachep->flags & SLAB_POISON) {
 #ifdef CONFIG_DEBUG_PAGEALLOC
@@ -2886,7 +2865,7 @@ retry:
 
 	while (batchcount > 0) {
 		struct list_head *entry;
-		struct slab *slabp;
+		struct page *page;
 		/* Get slab alloc is to come from. */
 		entry = n->slabs_partial.next;
 		if (entry == &n->slabs_partial) {
@@ -2896,7 +2875,7 @@ retry:
 				goto must_grow;
 		}
 
-		slabp = list_entry(entry, struct slab, list);
+		page = list_entry(entry, struct page, lru);
 		check_spinlock_acquired(cachep);
 
 		/*
@@ -2904,23 +2883,23 @@ retry:
 		 * there must be at least one object available for
 		 * allocation.
 		 */
-		BUG_ON(slabp->active >= cachep->num);
+		BUG_ON(page->active >= cachep->num);
 
-		while (slabp->active < cachep->num && batchcount--) {
+		while (page->active < cachep->num && batchcount--) {
 			STATS_INC_ALLOCED(cachep);
 			STATS_INC_ACTIVE(cachep);
 			STATS_SET_HIGH(cachep);
 
-			ac_put_obj(cachep, ac, slab_get_obj(cachep, slabp,
+			ac_put_obj(cachep, ac, slab_get_obj(cachep, page,
 									node));
 		}
 
 		/* move slabp to correct slabp list: */
-		list_del(&slabp->list);
-		if (slabp->active == cachep->num)
-			list_add(&slabp->list, &n->slabs_full);
+		list_del(&page->lru);
+		if (page->active == cachep->num)
+			list_add(&page->list, &n->slabs_full);
 		else
-			list_add(&slabp->list, &n->slabs_partial);
+			list_add(&page->list, &n->slabs_partial);
 	}
 
 must_grow:
@@ -3175,7 +3154,7 @@ static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
 				int nodeid)
 {
 	struct list_head *entry;
-	struct slab *slabp;
+	struct page *page;
 	struct kmem_cache_node *n;
 	void *obj;
 	int x;
@@ -3195,24 +3174,24 @@ retry:
 			goto must_grow;
 	}
 
-	slabp = list_entry(entry, struct slab, list);
+	page = list_entry(entry, struct page, lru);
 	check_spinlock_acquired_node(cachep, nodeid);
 
 	STATS_INC_NODEALLOCS(cachep);
 	STATS_INC_ACTIVE(cachep);
 	STATS_SET_HIGH(cachep);
 
-	BUG_ON(slabp->active == cachep->num);
+	BUG_ON(page->active == cachep->num);
 
-	obj = slab_get_obj(cachep, slabp, nodeid);
+	obj = slab_get_obj(cachep, page, nodeid);
 	n->free_objects--;
 	/* move slabp to correct slabp list: */
-	list_del(&slabp->list);
+	list_del(&page->lru);
 
-	if (slabp->active == cachep->num)
-		list_add(&slabp->list, &n->slabs_full);
+	if (page->active == cachep->num)
+		list_add(&page->lru, &n->slabs_full);
 	else
-		list_add(&slabp->list, &n->slabs_partial);
+		list_add(&page->lru, &n->slabs_partial);
 
 	spin_unlock(&n->list_lock);
 	goto done;
@@ -3362,21 +3341,21 @@ static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
 
 	for (i = 0; i < nr_objects; i++) {
 		void *objp;
-		struct slab *slabp;
+		struct page *page;
 
 		clear_obj_pfmemalloc(&objpp[i]);
 		objp = objpp[i];
 
-		slabp = virt_to_slab(objp);
+		page = virt_to_head_page(objp);
 		n = cachep->node[node];
-		list_del(&slabp->list);
+		list_del(&page->lru);
 		check_spinlock_acquired_node(cachep, node);
-		slab_put_obj(cachep, slabp, objp, node);
+		slab_put_obj(cachep, page, objp, node);
 		STATS_DEC_ACTIVE(cachep);
 		n->free_objects++;
 
 		/* fixup slab chains */
-		if (slabp->active == 0) {
+		if (page->active == 0) {
 			if (n->free_objects > n->free_limit) {
 				n->free_objects -= cachep->num;
 				/* No need to drop any previously held
@@ -3385,16 +3364,16 @@ static void free_block(struct kmem_cache *cachep, void **objpp, int nr_objects,
 				 * a different cache, refer to comments before
 				 * alloc_slabmgmt.
 				 */
-				slab_destroy(cachep, slabp);
+				slab_destroy(cachep, page);
 			} else {
-				list_add(&slabp->list, &n->slabs_free);
+				list_add(&page->lru, &n->slabs_free);
 			}
 		} else {
 			/* Unconditionally move a slab to the end of the
 			 * partial list on free - maximum time for the
 			 * other objects to be freed, too.
 			 */
-			list_add_tail(&slabp->list, &n->slabs_partial);
+			list_add_tail(&page->lru, &n->slabs_partial);
 		}
 	}
 }
@@ -3434,10 +3413,10 @@ free_done:
 
 		p = n->slabs_free.next;
 		while (p != &(n->slabs_free)) {
-			struct slab *slabp;
+			struct page *page;
 
-			slabp = list_entry(p, struct slab, list);
-			BUG_ON(slabp->active);
+			page = list_entry(p, struct page, lru);
+			BUG_ON(page->active);
 
 			i++;
 			p = p->next;
@@ -4041,7 +4020,7 @@ out:
 #ifdef CONFIG_SLABINFO
 void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo)
 {
-	struct slab *slabp;
+	struct page *page;
 	unsigned long active_objs;
 	unsigned long num_objs;
 	unsigned long active_slabs = 0;
@@ -4061,22 +4040,22 @@ void get_slabinfo(struct kmem_cache *cachep, struct slabinfo *sinfo)
 		check_irq_on();
 		spin_lock_irq(&n->list_lock);
 
-		list_for_each_entry(slabp, &n->slabs_full, list) {
-			if (slabp->active != cachep->num && !error)
+		list_for_each_entry(page, &n->slabs_full, lru) {
+			if (page->active != cachep->num && !error)
 				error = "slabs_full accounting error";
 			active_objs += cachep->num;
 			active_slabs++;
 		}
-		list_for_each_entry(slabp, &n->slabs_partial, list) {
-			if (slabp->active == cachep->num && !error)
+		list_for_each_entry(page, &n->slabs_partial, lru) {
+			if (page->active == cachep->num && !error)
 				error = "slabs_partial accounting error";
-			if (!slabp->active && !error)
+			if (!page->active && !error)
 				error = "slabs_partial accounting error";
-			active_objs += slabp->active;
+			active_objs += page->active;
 			active_slabs++;
 		}
-		list_for_each_entry(slabp, &n->slabs_free, list) {
-			if (slabp->active && !error)
+		list_for_each_entry(page, &n->slabs_free, lru) {
+			if (page->active && !error)
 				error = "slabs_free accounting error";
 			num_slabs++;
 		}
@@ -4229,19 +4208,20 @@ static inline int add_caller(unsigned long *n, unsigned long v)
 	return 1;
 }
 
-static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s)
+static void handle_slab(unsigned long *n, struct kmem_cache *c,
+						struct page *page)
 {
 	void *p;
 	int i, j;
 
 	if (n[0] == n[1])
 		return;
-	for (i = 0, p = s->s_mem; i < c->num; i++, p += c->size) {
+	for (i = 0, p = page->s_mem; i < c->num; i++, p += c->size) {
 		bool active = true;
 
-		for (j = s->active; j < c->num; j++) {
+		for (j = page->active; j < c->num; j++) {
 			/* Skip freed item */
-			if (slab_bufctl(s)[j] == i) {
+			if (slab_bufctl(page)[j] == i) {
 				active = false;
 				break;
 			}
@@ -4273,7 +4253,7 @@ static void show_symbol(struct seq_file *m, unsigned long address)
 static int leaks_show(struct seq_file *m, void *p)
 {
 	struct kmem_cache *cachep = list_entry(p, struct kmem_cache, list);
-	struct slab *slabp;
+	struct page *page;
 	struct kmem_cache_node *n;
 	const char *name;
 	unsigned long *x = m->private;
@@ -4297,10 +4277,10 @@ static int leaks_show(struct seq_file *m, void *p)
 		check_irq_on();
 		spin_lock_irq(&n->list_lock);
 
-		list_for_each_entry(slabp, &n->slabs_full, list)
-			handle_slab(x, cachep, slabp);
-		list_for_each_entry(slabp, &n->slabs_partial, list)
-			handle_slab(x, cachep, slabp);
+		list_for_each_entry(page, &n->slabs_full, lru)
+			handle_slab(x, cachep, page);
+		list_for_each_entry(page, &n->slabs_partial, lru)
+			handle_slab(x, cachep, page);
 		spin_unlock_irq(&n->list_lock);
 	}
 	name = cachep->name;
-- 
cgit v1.2.3


From 7ecccf9d1e416fe61bb1caa0a94605b522feeaf3 Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 24 Oct 2013 10:07:50 +0900
Subject: slab: remove useless statement for checking pfmemalloc

Now, virt_to_page(page->s_mem) is same as the page,
because slab use this structure for management.
So remove useless statement.

Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index 0e7f2e73e08e..fbb594f2259a 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -750,9 +750,7 @@ static struct array_cache *alloc_arraycache(int node, int entries,
 
 static inline bool is_slab_pfmemalloc(struct page *page)
 {
-	struct page *mem_page = virt_to_page(page->s_mem);
-
-	return PageSlabPfmemalloc(mem_page);
+	return PageSlabPfmemalloc(page);
 }
 
 /* Clears pfmemalloc_active if no slabs have pfmalloc set */
@@ -817,7 +815,7 @@ static void *__ac_get_obj(struct kmem_cache *cachep, struct array_cache *ac,
 		n = cachep->node[numa_mem_id()];
 		if (!list_empty(&n->slabs_free) && force_refill) {
 			struct page *page = virt_to_head_page(objp);
-			ClearPageSlabPfmemalloc(virt_to_head_page(page->s_mem));
+			ClearPageSlabPfmemalloc(page);
 			clear_obj_pfmemalloc(&objp);
 			recheck_pfmemalloc_active(cachep, ac);
 			return objp;
@@ -850,8 +848,7 @@ static void *__ac_put_obj(struct kmem_cache *cachep, struct array_cache *ac,
 	if (unlikely(pfmemalloc_active)) {
 		/* Some pfmemalloc slabs exist, check if this is one */
 		struct page *page = virt_to_head_page(objp);
-		struct page *mem_page = virt_to_head_page(page->s_mem);
-		if (PageSlabPfmemalloc(mem_page))
+		if (PageSlabPfmemalloc(page))
 			set_obj_pfmemalloc(&objp);
 	}
 
-- 
cgit v1.2.3


From e7444d9b7d49898a667074122bed2dcedf349305 Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Thu, 24 Oct 2013 10:07:51 +0900
Subject: slab: rename slab_bufctl to slab_freelist

Now, bufctl is not proper name to this array.
So change it.

Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index fbb594f2259a..af2db76e1f5a 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2550,7 +2550,7 @@ static struct freelist *alloc_slabmgmt(struct kmem_cache *cachep,
 	return freelist;
 }
 
-static inline unsigned int *slab_bufctl(struct page *page)
+static inline unsigned int *slab_freelist(struct page *page)
 {
 	return (unsigned int *)(page->freelist);
 }
@@ -2597,7 +2597,7 @@ static void cache_init_objs(struct kmem_cache *cachep,
 		if (cachep->ctor)
 			cachep->ctor(objp);
 #endif
-		slab_bufctl(page)[i] = i;
+		slab_freelist(page)[i] = i;
 	}
 }
 
@@ -2616,7 +2616,7 @@ static void *slab_get_obj(struct kmem_cache *cachep, struct page *page,
 {
 	void *objp;
 
-	objp = index_to_obj(cachep, page, slab_bufctl(page)[page->active]);
+	objp = index_to_obj(cachep, page, slab_freelist(page)[page->active]);
 	page->active++;
 #if DEBUG
 	WARN_ON(page_to_nid(virt_to_page(objp)) != nodeid);
@@ -2637,7 +2637,7 @@ static void slab_put_obj(struct kmem_cache *cachep, struct page *page,
 
 	/* Verify double free bug */
 	for (i = page->active; i < cachep->num; i++) {
-		if (slab_bufctl(page)[i] == objnr) {
+		if (slab_freelist(page)[i] == objnr) {
 			printk(KERN_ERR "slab: double free detected in cache "
 					"'%s', objp %p\n", cachep->name, objp);
 			BUG();
@@ -2645,7 +2645,7 @@ static void slab_put_obj(struct kmem_cache *cachep, struct page *page,
 	}
 #endif
 	page->active--;
-	slab_bufctl(page)[page->active] = objnr;
+	slab_freelist(page)[page->active] = objnr;
 }
 
 /*
@@ -4218,7 +4218,7 @@ static void handle_slab(unsigned long *n, struct kmem_cache *c,
 
 		for (j = page->active; j < c->num; j++) {
 			/* Skip freed item */
-			if (slab_bufctl(page)[j] == i) {
+			if (slab_freelist(page)[j] == i) {
 				active = false;
 				break;
 			}
-- 
cgit v1.2.3


From 0172f779e4314639a8ed440082cfe9e3450954e8 Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Wed, 30 Oct 2013 19:04:00 +0900
Subject: slab: fix to calm down kmemleak warning

After using struct page as slab management, we should not call
kmemleak_scan_area(), since struct page isn't the tracking object of
kmemleak. Without this patch and if CONFIG_DEBUG_KMEMLEAK is enabled,
so many kmemleak warnings are printed.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 8 --------
 1 file changed, 8 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index af2db76e1f5a..a8a93497d7d6 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -2531,14 +2531,6 @@ static struct freelist *alloc_slabmgmt(struct kmem_cache *cachep,
 		/* Slab management obj is off-slab. */
 		freelist = kmem_cache_alloc_node(cachep->freelist_cache,
 					      local_flags, nodeid);
-		/*
-		 * If the first object in the slab is leaked (it's allocated
-		 * but no one has a reference to it), we want to make sure
-		 * kmemleak does not treat the ->s_mem pointer as a reference
-		 * to the object. Otherwise we will not report the leak.
-		 */
-		kmemleak_scan_area(&page->lru, sizeof(struct list_head),
-				   local_flags);
 		if (!freelist)
 			return NULL;
 	} else {
-- 
cgit v1.2.3


From 7e00735520ffb00bda3e08c441d0a4dba42913a7 Mon Sep 17 00:00:00 2001
From: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Date: Wed, 30 Oct 2013 19:04:01 +0900
Subject: slab: replace non-existing 'struct freelist *' with 'void *'

There is no 'strcut freelist', but codes use pointer to 'struct freelist'.
Although compiler doesn't complain anything about this wrong usage and
codes work fine, but fixing it is better.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Pekka Enberg <penberg@iki.fi>
---
 mm/slab.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

(limited to 'mm/slab.c')

diff --git a/mm/slab.c b/mm/slab.c
index a8a93497d7d6..a983e3084332 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1954,7 +1954,7 @@ static void slab_destroy_debugcheck(struct kmem_cache *cachep,
  */
 static void slab_destroy(struct kmem_cache *cachep, struct page *page)
 {
-	struct freelist *freelist;
+	void *freelist;
 
 	freelist = page->freelist;
 	slab_destroy_debugcheck(cachep, page);
@@ -2520,11 +2520,11 @@ int __kmem_cache_shutdown(struct kmem_cache *cachep)
  * kmem_find_general_cachep till the initialization is complete.
  * Hence we cannot have freelist_cache same as the original cache.
  */
-static struct freelist *alloc_slabmgmt(struct kmem_cache *cachep,
+static void *alloc_slabmgmt(struct kmem_cache *cachep,
 				   struct page *page, int colour_off,
 				   gfp_t local_flags, int nodeid)
 {
-	struct freelist *freelist;
+	void *freelist;
 	void *addr = page_address(page);
 
 	if (OFF_SLAB(cachep)) {
@@ -2646,7 +2646,7 @@ static void slab_put_obj(struct kmem_cache *cachep, struct page *page,
  * virtual address for kfree, ksize, and slab debugging.
  */
 static void slab_map_pages(struct kmem_cache *cache, struct page *page,
-			   struct freelist *freelist)
+			   void *freelist)
 {
 	page->slab_cache = cache;
 	page->freelist = freelist;
@@ -2659,7 +2659,7 @@ static void slab_map_pages(struct kmem_cache *cache, struct page *page,
 static int cache_grow(struct kmem_cache *cachep,
 		gfp_t flags, int nodeid, struct page *page)
 {
-	struct freelist *freelist;
+	void *freelist;
 	size_t offset;
 	gfp_t local_flags;
 	struct kmem_cache_node *n;
-- 
cgit v1.2.3