Merge branch 'master'

11 files changed, 186 insertions, 83 deletions

diff --git a/mm/bootmem.c b/mm/bootmem.c
index d3e3bd2..d213fed 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -401,7 +401,7 @@ unsigned long __init free_all_bootmem (void)
 	return(free_all_bootmem_core(NODE_DATA(0)));
 }
 
-void * __init __alloc_bootmem(unsigned long size, unsigned long align, unsigned long goal)
+void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align, unsigned long goal)
 {
 	bootmem_data_t *bdata;
 	void *ptr;
@@ -409,7 +409,14 @@ void * __init __alloc_bootmem(unsigned long size, unsigned long align, unsigned
 	list_for_each_entry(bdata, &bdata_list, list)
 		if ((ptr = __alloc_bootmem_core(bdata, size, align, goal, 0)))
 			return(ptr);
+	return NULL;
+}
 
+void * __init __alloc_bootmem(unsigned long size, unsigned long align, unsigned long goal)
+{
+	void *mem = __alloc_bootmem_nopanic(size,align,goal);
+	if (mem)
+		return mem;
 	/*
 	 * Whoops, we cannot satisfy the allocation request.
 	 */
diff --git a/mm/madvise.c b/mm/madvise.c
index af3d573..4e19615 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -168,6 +168,9 @@ static long madvise_remove(struct vm_area_struct *vma,
 			return -EINVAL;
 	}
 
+	if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE))
+		return -EACCES;
+
 	mapping = vma->vm_file->f_mapping;
 
 	offset = (loff_t)(start - vma->vm_start)
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index dec8249..8778f58 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1761,7 +1761,6 @@ static void gather_stats(struct page *page, void *private, int pte_dirty)
 		md->mapcount_max = count;
 
 	md->node[page_to_nid(page)]++;
-	cond_resched();
 }
 
 #ifdef CONFIG_HUGETLB_PAGE
diff --git a/mm/migrate.c b/mm/migrate.c
index 09f6e4a..d444229 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -16,8 +16,7 @@
 #include <linux/module.h>
 #include <linux/swap.h>
 #include <linux/pagemap.h>
-#include <linux/buffer_head.h>	/* for try_to_release_page(),
-					buffer_heads_over_limit */
+#include <linux/buffer_head.h>
 #include <linux/mm_inline.h>
 #include <linux/pagevec.h>
 #include <linux/rmap.h>
@@ -28,8 +27,6 @@
 
 #include "internal.h"
 
-#include "internal.h"
-
 /* The maximum number of pages to take off the LRU for migration */
 #define MIGRATE_CHUNK_SIZE 256
 
@@ -176,7 +173,6 @@ unlock_retry:
 retry:
 	return -EAGAIN;
 }
-EXPORT_SYMBOL(swap_page);
 
 /*
  * Remove references for a page and establish the new page with the correct
@@ -234,7 +230,7 @@ int migrate_page_remove_references(struct page *newpage,
 	if (!page_mapping(page) || page_count(page) != nr_refs ||
 			*radix_pointer != page) {
 		write_unlock_irq(&mapping->tree_lock);
-		return 1;
+		return -EAGAIN;
 	}
 
 	/*
diff --git a/mm/mmap.c b/mm/mmap.c
index e780d19..e6ee123 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -121,14 +121,26 @@ int __vm_enough_memory(long pages, int cap_sys_admin)
 		 * only call if we're about to fail.
 		 */
 		n = nr_free_pages();
+
+		/*
+		 * Leave reserved pages. The pages are not for anonymous pages.
+		 */
+		if (n <= totalreserve_pages)
+			goto error;
+		else
+			n -= totalreserve_pages;
+
+		/*
+		 * Leave the last 3% for root
+		 */
 		if (!cap_sys_admin)
 			n -= n / 32;
 		free += n;
 
 		if (free > pages)
 			return 0;
-		vm_unacct_memory(pages);
-		return -ENOMEM;
+
+		goto error;
 	}
 
 	allowed = (totalram_pages - hugetlb_total_pages())
@@ -150,7 +162,7 @@ int __vm_enough_memory(long pages, int cap_sys_admin)
 	 */
 	if (atomic_read(&vm_committed_space) < (long)allowed)
 		return 0;
-
+error:
 	vm_unacct_memory(pages);
 
 	return -ENOMEM;
@@ -220,6 +232,17 @@ asmlinkage unsigned long sys_brk(unsigned long brk)
 
 	if (brk < mm->end_code)
 		goto out;
+
+	/*
+	 * Check against rlimit here. If this check is done later after the test
+	 * of oldbrk with newbrk then it can escape the test and let the data
+	 * segment grow beyond its set limit the in case where the limit is
+	 * not page aligned -Ram Gupta
+	 */
+	rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
+	if (rlim < RLIM_INFINITY && brk - mm->start_data > rlim)
+		goto out;
+
 	newbrk = PAGE_ALIGN(brk);
 	oldbrk = PAGE_ALIGN(mm->brk);
 	if (oldbrk == newbrk)
@@ -232,11 +255,6 @@ asmlinkage unsigned long sys_brk(unsigned long brk)
 		goto out;
 	}
 
-	/* Check against rlimit.. */
-	rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
-	if (rlim < RLIM_INFINITY && brk - mm->start_data > rlim)
-		goto out;
-
 	/* Check against existing mmap mappings. */
 	if (find_vma_intersection(mm, oldbrk, newbrk+PAGE_SIZE))
 		goto out;
diff --git a/mm/nommu.c b/mm/nommu.c
index db45efa..029fada 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1147,14 +1147,26 @@ int __vm_enough_memory(long pages, int cap_sys_admin)
 		 * only call if we're about to fail.
 		 */
 		n = nr_free_pages();
+
+		/*
+		 * Leave reserved pages. The pages are not for anonymous pages.
+		 */
+		if (n <= totalreserve_pages)
+			goto error;
+		else
+			n -= totalreserve_pages;
+
+		/*
+		 * Leave the last 3% for root
+		 */
 		if (!cap_sys_admin)
 			n -= n / 32;
 		free += n;
 
 		if (free > pages)
 			return 0;
-		vm_unacct_memory(pages);
-		return -ENOMEM;
+
+		goto error;
 	}
 
 	allowed = totalram_pages * sysctl_overcommit_ratio / 100;
@@ -1175,7 +1187,7 @@ int __vm_enough_memory(long pages, int cap_sys_admin)
 	 */
 	if (atomic_read(&vm_committed_space) < (long)allowed)
 		return 0;
-
+error:
 	vm_unacct_memory(pages);
 
 	return -ENOMEM;
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 78747af..042e643 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -46,15 +46,25 @@
 unsigned long badness(struct task_struct *p, unsigned long uptime)
 {
 	unsigned long points, cpu_time, run_time, s;
-	struct list_head *tsk;
+	struct mm_struct *mm;
+	struct task_struct *child;
 
-	if (!p->mm)
+	task_lock(p);
+	mm = p->mm;
+	if (!mm) {
+		task_unlock(p);
 		return 0;
+	}
 
 	/*
 	 * The memory size of the process is the basis for the badness.
 	 */
-	points = p->mm->total_vm;
+	points = mm->total_vm;
+
+	/*
+	 * After this unlock we can no longer dereference local variable `mm'
+	 */
+	task_unlock(p);
 
 	/*
 	 * Processes which fork a lot of child processes are likely
@@ -64,11 +74,11 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
 	 * child is eating the vast majority of memory, adding only half
 	 * to the parents will make the child our kill candidate of choice.
 	 */
-	list_for_each(tsk, &p->children) {
-		struct task_struct *chld;
-		chld = list_entry(tsk, struct task_struct, sibling);
-		if (chld->mm != p->mm && chld->mm)
-			points += chld->mm->total_vm/2 + 1;
+	list_for_each_entry(child, &p->children, sibling) {
+		task_lock(child);
+		if (child->mm != mm && child->mm)
+			points += child->mm->total_vm/2 + 1;
+		task_unlock(child);
 	}
 
 	/*
@@ -244,17 +254,24 @@ static void __oom_kill_task(task_t *p, const char *message)
 	force_sig(SIGKILL, p);
 }
 
-static struct mm_struct *oom_kill_task(task_t *p, const char *message)
+static int oom_kill_task(task_t *p, const char *message)
 {
-	struct mm_struct *mm = get_task_mm(p);
+	struct mm_struct *mm;
 	task_t * g, * q;
 
-	if (!mm)
-		return NULL;
-	if (mm == &init_mm) {
-		mmput(mm);
-		return NULL;
-	}
+	mm = p->mm;
+
+	/* WARNING: mm may not be dereferenced since we did not obtain its
+	 * value from get_task_mm(p).  This is OK since all we need to do is
+	 * compare mm to q->mm below.
+	 *
+	 * Furthermore, even if mm contains a non-NULL value, p->mm may
+	 * change to NULL at any time since we do not hold task_lock(p).
+	 * However, this is of no concern to us.
+	 */
+
+	if (mm == NULL || mm == &init_mm)
+		return 1;
 
 	__oom_kill_task(p, message);
 	/*
@@ -266,13 +283,12 @@ static struct mm_struct *oom_kill_task(task_t *p, const char *message)
 			__oom_kill_task(q, message);
 	while_each_thread(g, q);
 
-	return mm;
+	return 0;
 }
 
-static struct mm_struct *oom_kill_process(struct task_struct *p,
-				unsigned long points, const char *message)
+static int oom_kill_process(struct task_struct *p, unsigned long points,
+		const char *message)
 {
- 	struct mm_struct *mm;
 	struct task_struct *c;
 	struct list_head *tsk;
 
@@ -283,9 +299,8 @@ static struct mm_struct *oom_kill_process(struct task_struct *p,
 		c = list_entry(tsk, struct task_struct, sibling);
 		if (c->mm == p->mm)
 			continue;
-		mm = oom_kill_task(c, message);
-		if (mm)
-			return mm;
+		if (!oom_kill_task(c, message))
+			return 0;
 	}
 	return oom_kill_task(p, message);
 }
@@ -300,7 +315,6 @@ static struct mm_struct *oom_kill_process(struct task_struct *p,
  */
 void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
 {
-	struct mm_struct *mm = NULL;
 	task_t *p;
 	unsigned long points = 0;
 
@@ -320,12 +334,12 @@ void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
 	 */
 	switch (constrained_alloc(zonelist, gfp_mask)) {
 	case CONSTRAINT_MEMORY_POLICY:
-		mm = oom_kill_process(current, points,
+		oom_kill_process(current, points,
 				"No available memory (MPOL_BIND)");
 		break;
 
 	case CONSTRAINT_CPUSET:
-		mm = oom_kill_process(current, points,
+		oom_kill_process(current, points,
 				"No available memory in cpuset");
 		break;
 
@@ -347,8 +361,7 @@ retry:
 			panic("Out of memory and no killable processes...\n");
 		}
 
-		mm = oom_kill_process(p, points, "Out of memory");
-		if (!mm)
+		if (oom_kill_process(p, points, "Out of memory"))
 			goto retry;
 
 		break;
@@ -357,8 +370,6 @@ retry:
 out:
 	read_unlock(&tasklist_lock);
 	cpuset_unlock();
-	if (mm)
-		mmput(mm);
 
 	/*
 	 * Give "p" a good chance of killing itself before we
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 6dcce3a..75d7f48 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -72,13 +72,12 @@ int dirty_background_ratio = 10;
 int vm_dirty_ratio = 40;
 
 /*
- * The interval between `kupdate'-style writebacks, in centiseconds
- * (hundredths of a second)
+ * The interval between `kupdate'-style writebacks, in jiffies
  */
 int dirty_writeback_interval = 5 * HZ;
 
 /*
- * The longest number of centiseconds for which data is allowed to remain dirty
+ * The longest number of jiffies for which data is allowed to remain dirty
  */
 int dirty_expire_interval = 30 * HZ;
 
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index dc523a1..123c605 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -51,6 +51,7 @@ nodemask_t node_possible_map __read_mostly = NODE_MASK_ALL;
 EXPORT_SYMBOL(node_possible_map);
 unsigned long totalram_pages __read_mostly;
 unsigned long totalhigh_pages __read_mostly;
+unsigned long totalreserve_pages __read_mostly;
 long nr_swap_pages;
 int percpu_pagelist_fraction;
 
@@ -151,7 +152,8 @@ static void bad_page(struct page *page)
 			1 << PG_reclaim |
 			1 << PG_slab    |
 			1 << PG_swapcache |
-			1 << PG_writeback );
+			1 << PG_writeback |
+			1 << PG_buddy );
 	set_page_count(page, 0);
 	reset_page_mapcount(page);
 	page->mapping = NULL;
@@ -230,18 +232,20 @@ static inline void prep_zero_page(struct page *page, int order, gfp_t gfp_flags)
  * zone->lock is already acquired when we use these.
  * So, we don't need atomic page->flags operations here.
  */
-static inline unsigned long page_order(struct page *page) {
+static inline unsigned long page_order(struct page *page)
+{
 	return page_private(page);
 }
 
-static inline void set_page_order(struct page *page, int order) {
+static inline void set_page_order(struct page *page, int order)
+{
 	set_page_private(page, order);
-	__SetPagePrivate(page);
+	__SetPageBuddy(page);
 }
 
 static inline void rmv_page_order(struct page *page)
 {
-	__ClearPagePrivate(page);
+	__ClearPageBuddy(page);
 	set_page_private(page, 0);
 }
 
@@ -280,11 +284,13 @@ __find_combined_index(unsigned long page_idx, unsigned int order)
  * This function checks whether a page is free && is the buddy
  * we can do coalesce a page and its buddy if
  * (a) the buddy is not in a hole &&
- * (b) the buddy is free &&
- * (c) the buddy is on the buddy system &&
- * (d) a page and its buddy have the same order.
- * for recording page's order, we use page_private(page) and PG_private.
+ * (b) the buddy is in the buddy system &&
+ * (c) a page and its buddy have the same order.
  *
+ * For recording whether a page is in the buddy system, we use PG_buddy.
+ * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
+ *
+ * For recording page's order, we use page_private(page).
  */
 static inline int page_is_buddy(struct page *page, int order)
 {
@@ -293,11 +299,11 @@ static inline int page_is_buddy(struct page *page, int order)
 		return 0;
 #endif
 
-       if (PagePrivate(page)           &&
-           (page_order(page) == order) &&
-            page_count(page) == 0)
-               return 1;
-       return 0;
+	if (PageBuddy(page) && page_order(page) == order) {
+		BUG_ON(page_count(page) != 0);
+		return 1;
+	}
+	return 0;
 }
 
 /*
@@ -313,7 +319,7 @@ static inline int page_is_buddy(struct page *page, int order)
  * as necessary, plus some accounting needed to play nicely with other
  * parts of the VM system.
  * At each level, we keep a list of pages, which are heads of continuous
- * free pages of length of (1 << order) and marked with PG_Private.Page's
+ * free pages of length of (1 << order) and marked with PG_buddy. Page's
  * order is recorded in page_private(page) field.
  * So when we are allocating or freeing one, we can derive the state of the
  * other.  That is, if we allocate a small block, and both were   
@@ -376,7 +382,8 @@ static inline int free_pages_check(struct page *page)
 			1 << PG_slab	|
 			1 << PG_swapcache |
 			1 << PG_writeback |
-			1 << PG_reserved ))))
+			1 << PG_reserved |
+			1 << PG_buddy ))))
 		bad_page(page);
 	if (PageDirty(page))
 		__ClearPageDirty(page);
@@ -524,7 +531,8 @@ static int prep_new_page(struct page *page, int order, gfp_t gfp_flags)
 			1 << PG_slab    |
 			1 << PG_swapcache |
 			1 << PG_writeback |
-			1 << PG_reserved ))))
+			1 << PG_reserved |
+			1 << PG_buddy ))))
 		bad_page(page);
 
 	/*
@@ -2472,6 +2480,38 @@ void __init page_alloc_init(void)
 }
 
 /*
+ * calculate_totalreserve_pages - called when sysctl_lower_zone_reserve_ratio
+ *	or min_free_kbytes changes.
+ */
+static void calculate_totalreserve_pages(void)
+{
+	struct pglist_data *pgdat;
+	unsigned long reserve_pages = 0;
+	int i, j;
+
+	for_each_online_pgdat(pgdat) {
+		for (i = 0; i < MAX_NR_ZONES; i++) {
+			struct zone *zone = pgdat->node_zones + i;
+			unsigned long max = 0;
+
+			/* Find valid and maximum lowmem_reserve in the zone */
+			for (j = i; j < MAX_NR_ZONES; j++) {
+				if (zone->lowmem_reserve[j] > max)
+					max = zone->lowmem_reserve[j];
+			}
+
+			/* we treat pages_high as reserved pages. */
+			max += zone->pages_high;
+
+			if (max > zone->present_pages)
+				max = zone->present_pages;
+			reserve_pages += max;
+		}
+	}
+	totalreserve_pages = reserve_pages;
+}
+
+/*
  * setup_per_zone_lowmem_reserve - called whenever
  *	sysctl_lower_zone_reserve_ratio changes.  Ensures that each zone
  *	has a correct pages reserved value, so an adequate number of
@@ -2502,6 +2542,9 @@ static void setup_per_zone_lowmem_reserve(void)
 			}
 		}
 	}
+
+	/* update totalreserve_pages */
+	calculate_totalreserve_pages();
 }
 
 /*
@@ -2556,6 +2599,9 @@ void setup_per_zone_pages_min(void)
 		zone->pages_high  = zone->pages_min + tmp / 2;
 		spin_unlock_irqrestore(&zone->lru_lock, flags);
 	}
+
+	/* update totalreserve_pages */
+	calculate_totalreserve_pages();
 }
 
 /*
diff --git a/mm/slab.c b/mm/slab.c
index f055c14..e6ef9bd5 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -420,6 +420,7 @@ struct kmem_cache {
 	unsigned long max_freeable;
 	unsigned long node_allocs;
 	unsigned long node_frees;
+	unsigned long node_overflow;
 	atomic_t allochit;
 	atomic_t allocmiss;
 	atomic_t freehit;
@@ -465,6 +466,7 @@ struct kmem_cache {
 #define	STATS_INC_ERR(x)	((x)->errors++)
 #define	STATS_INC_NODEALLOCS(x)	((x)->node_allocs++)
 #define	STATS_INC_NODEFREES(x)	((x)->node_frees++)
+#define STATS_INC_ACOVERFLOW(x)   ((x)->node_overflow++)
 #define	STATS_SET_FREEABLE(x, i)					\
 	do {								\
 		if ((x)->max_freeable < i)				\
@@ -484,6 +486,7 @@ struct kmem_cache {
 #define	STATS_INC_ERR(x)	do { } while (0)
 #define	STATS_INC_NODEALLOCS(x)	do { } while (0)
 #define	STATS_INC_NODEFREES(x)	do { } while (0)
+#define STATS_INC_ACOVERFLOW(x)   do { } while (0)
 #define	STATS_SET_FREEABLE(x, i) do { } while (0)
 #define STATS_INC_ALLOCHIT(x)	do { } while (0)
 #define STATS_INC_ALLOCMISS(x)	do { } while (0)
@@ -1453,7 +1456,14 @@ static void *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, int nodeid)
 	int i;
 
 	flags |= cachep->gfpflags;
+#ifndef CONFIG_MMU
+	/* nommu uses slab's for process anonymous memory allocations, so
+	 * requires __GFP_COMP to properly refcount higher order allocations"
+	 */
+	page = alloc_pages_node(nodeid, (flags | __GFP_COMP), cachep->gfporder);
+#else
 	page = alloc_pages_node(nodeid, flags, cachep->gfporder);
+#endif
 	if (!page)
 		return NULL;
 	addr = page_address(page);
@@ -2318,13 +2328,15 @@ EXPORT_SYMBOL(kmem_cache_destroy);
 
 /* Get the memory for a slab management obj. */
 static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
-				   int colour_off, gfp_t local_flags)
+				   int colour_off, gfp_t local_flags,
+				   int nodeid)
 {
 	struct slab *slabp;
 
 	if (OFF_SLAB(cachep)) {
 		/* Slab management obj is off-slab. */
-		slabp = kmem_cache_alloc(cachep->slabp_cache, local_flags);
+		slabp = kmem_cache_alloc_node(cachep->slabp_cache,
+					      local_flags, nodeid);
 		if (!slabp)
 			return NULL;
 	} else {
@@ -2334,6 +2346,7 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp,
 	slabp->inuse = 0;
 	slabp->colouroff = colour_off;
 	slabp->s_mem = objp + colour_off;
+	slabp->nodeid = nodeid;
 	return slabp;
 }
 
@@ -2519,7 +2532,7 @@ static int cache_grow(struct kmem_cache *cachep, gfp_t flags, int nodeid)
 		goto failed;
 
 	/* Get slab management. */
-	slabp = alloc_slabmgmt(cachep, objp, offset, local_flags);
+	slabp = alloc_slabmgmt(cachep, objp, offset, local_flags, nodeid);
 	if (!slabp)
 		goto opps1;
 
@@ -3080,9 +3093,11 @@ static inline void __cache_free(struct kmem_cache *cachep, void *objp)
 			if (l3->alien && l3->alien[nodeid]) {
 				alien = l3->alien[nodeid];
 				spin_lock(&alien->lock);
-				if (unlikely(alien->avail == alien->limit))
+				if (unlikely(alien->avail == alien->limit)) {
+					STATS_INC_ACOVERFLOW(cachep);
 					__drain_alien_cache(cachep,
 							    alien, nodeid);
+				}
 				alien->entry[alien->avail++] = objp;
 				spin_unlock(&alien->lock);
 			} else {
@@ -3760,7 +3775,7 @@ static void print_slabinfo_header(struct seq_file *m)
 	seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>");
 #if STATS
 	seq_puts(m, " : globalstat <listallocs> <maxobjs> <grown> <reaped> "
-		 "<error> <maxfreeable> <nodeallocs> <remotefrees>");
+		 "<error> <maxfreeable> <nodeallocs> <remotefrees> <alienoverflow>");
 	seq_puts(m, " : cpustat <allochit> <allocmiss> <freehit> <freemiss>");
 #endif
 	seq_putc(m, '\n');
@@ -3874,11 +3889,12 @@ static int s_show(struct seq_file *m, void *p)
 		unsigned long max_freeable = cachep->max_freeable;
 		unsigned long node_allocs = cachep->node_allocs;
 		unsigned long node_frees = cachep->node_frees;
+		unsigned long overflows = cachep->node_overflow;
 
 		seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu \
-				%4lu %4lu %4lu %4lu", allocs, high, grown,
+				%4lu %4lu %4lu %4lu %4lu", allocs, high, grown,
 				reaped, errors, max_freeable, node_allocs,
-				node_frees);
+				node_frees, overflows);
 	}
 	/* cpu stats */
 	{
diff --git a/mm/slob.c b/mm/slob.c
index 9bcc7e2..a68255b 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -354,9 +354,7 @@ void *__alloc_percpu(size_t size)
 	if (!pdata)
 		return NULL;
 
-	for (i = 0; i < NR_CPUS; i++) {
-		if (!cpu_possible(i))
-			continue;
+	for_each_possible_cpu(i) {
 		pdata->ptrs[i] = kmalloc(size, GFP_KERNEL);
 		if (!pdata->ptrs[i])
 			goto unwind_oom;
@@ -383,11 +381,9 @@ free_percpu(const void *objp)
 	int i;
 	struct percpu_data *p = (struct percpu_data *) (~(unsigned long) objp);
 
-	for (i = 0; i < NR_CPUS; i++) {
-		if (!cpu_possible(i))
-			continue;
+	for_each_possible_cpu(i)
 		kfree(p->ptrs[i]);
-	}
+
 	kfree(p);
 }
 EXPORT_SYMBOL(free_percpu);