Merge branch 'from-linus'

7 files changed, 226 insertions, 68 deletions

diff --git a/mm/memory.c b/mm/memory.c
index 2bee1f2..9abc600 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -82,6 +82,16 @@ EXPORT_SYMBOL(num_physpages);
 EXPORT_SYMBOL(high_memory);
 EXPORT_SYMBOL(vmalloc_earlyreserve);
 
+int randomize_va_space __read_mostly = 1;
+
+static int __init disable_randmaps(char *s)
+{
+	randomize_va_space = 0;
+	return 0;
+}
+__setup("norandmaps", disable_randmaps);
+
+
 /*
  * If a p?d_bad entry is found while walking page tables, report
  * the error, before resetting entry to p?d_none.  Usually (but
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 3bd7fb7..67af4ce 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -132,19 +132,29 @@ static int mpol_check_policy(int mode, nodemask_t *nodes)
 	}
 	return nodes_subset(*nodes, node_online_map) ? 0 : -EINVAL;
 }
+
 /* Generate a custom zonelist for the BIND policy. */
 static struct zonelist *bind_zonelist(nodemask_t *nodes)
 {
 	struct zonelist *zl;
-	int num, max, nd;
+	int num, max, nd, k;
 
 	max = 1 + MAX_NR_ZONES * nodes_weight(*nodes);
-	zl = kmalloc(sizeof(void *) * max, GFP_KERNEL);
+	zl = kmalloc(sizeof(struct zone *) * max, GFP_KERNEL);
 	if (!zl)
 		return NULL;
 	num = 0;
-	for_each_node_mask(nd, *nodes)
-		zl->zones[num++] = &NODE_DATA(nd)->node_zones[policy_zone];
+	/* First put in the highest zones from all nodes, then all the next 
+	   lower zones etc. Avoid empty zones because the memory allocator
+	   doesn't like them. If you implement node hot removal you
+	   have to fix that. */
+	for (k = policy_zone; k >= 0; k--) { 
+		for_each_node_mask(nd, *nodes) { 
+			struct zone *z = &NODE_DATA(nd)->node_zones[k];
+			if (z->present_pages > 0) 
+				zl->zones[num++] = z;
+		}
+	}
 	zl->zones[num] = NULL;
 	return zl;
 }
@@ -542,7 +552,7 @@ static void migrate_page_add(struct page *page, struct list_head *pagelist,
 	 */
 	if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(page) == 1) {
 		if (isolate_lru_page(page))
-			list_add(&page->lru, pagelist);
+			list_add_tail(&page->lru, pagelist);
 	}
 }
 
@@ -559,6 +569,7 @@ static int migrate_pages_to(struct list_head *pagelist,
 	LIST_HEAD(moved);
 	LIST_HEAD(failed);
 	int err = 0;
+	unsigned long offset = 0;
 	int nr_pages;
 	struct page *page;
 	struct list_head *p;
@@ -566,8 +577,21 @@ static int migrate_pages_to(struct list_head *pagelist,
 redo:
 	nr_pages = 0;
 	list_for_each(p, pagelist) {
-		if (vma)
-			page = alloc_page_vma(GFP_HIGHUSER, vma, vma->vm_start);
+		if (vma) {
+			/*
+			 * The address passed to alloc_page_vma is used to
+			 * generate the proper interleave behavior. We fake
+			 * the address here by an increasing offset in order
+			 * to get the proper distribution of pages.
+			 *
+			 * No decision has been made as to which page
+			 * a certain old page is moved to so we cannot
+			 * specify the correct address.
+			 */
+			page = alloc_page_vma(GFP_HIGHUSER, vma,
+					offset + vma->vm_start);
+			offset += PAGE_SIZE;
+		}
 		else
 			page = alloc_pages_node(dest, GFP_HIGHUSER, 0);
 
@@ -575,9 +599,9 @@ redo:
 			err = -ENOMEM;
 			goto out;
 		}
-		list_add(&page->lru, &newlist);
+		list_add_tail(&page->lru, &newlist);
 		nr_pages++;
-		if (nr_pages > MIGRATE_CHUNK_SIZE);
+		if (nr_pages > MIGRATE_CHUNK_SIZE)
 			break;
 	}
 	err = migrate_pages(pagelist, &newlist, &moved, &failed);
@@ -798,6 +822,8 @@ static int get_nodes(nodemask_t *nodes, const unsigned long __user *nmask,
 	nodes_clear(*nodes);
 	if (maxnode == 0 || !nmask)
 		return 0;
+	if (maxnode > PAGE_SIZE*BITS_PER_BYTE)
+		return -EINVAL;
 
 	nlongs = BITS_TO_LONGS(maxnode);
 	if ((maxnode % BITS_PER_LONG) == 0)
diff --git a/mm/nommu.c b/mm/nommu.c
index c10262d..99d2102 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -57,6 +57,8 @@ EXPORT_SYMBOL(vmalloc);
 EXPORT_SYMBOL(vfree);
 EXPORT_SYMBOL(vmalloc_to_page);
 EXPORT_SYMBOL(vmalloc_32);
+EXPORT_SYMBOL(vmap);
+EXPORT_SYMBOL(vunmap);
 
 /*
  * Handle all mappings that got truncated by a "truncate()"
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index b05ab8f..8123fad 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -58,15 +58,17 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
 
 	/*
 	 * Processes which fork a lot of child processes are likely
-	 * a good choice. We add the vmsize of the children if they
+	 * a good choice. We add half the vmsize of the children if they
 	 * have an own mm. This prevents forking servers to flood the
-	 * machine with an endless amount of children
+	 * machine with an endless amount of children. In case a single
+	 * 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;
+			points += chld->mm->total_vm/2 + 1;
 	}
 
 	/*
@@ -131,17 +133,47 @@ unsigned long badness(struct task_struct *p, unsigned long uptime)
 }
 
 /*
+ * Types of limitations to the nodes from which allocations may occur
+ */
+#define CONSTRAINT_NONE 1
+#define CONSTRAINT_MEMORY_POLICY 2
+#define CONSTRAINT_CPUSET 3
+
+/*
+ * Determine the type of allocation constraint.
+ */
+static inline int constrained_alloc(struct zonelist *zonelist, gfp_t gfp_mask)
+{
+#ifdef CONFIG_NUMA
+	struct zone **z;
+	nodemask_t nodes = node_online_map;
+
+	for (z = zonelist->zones; *z; z++)
+		if (cpuset_zone_allowed(*z, gfp_mask))
+			node_clear((*z)->zone_pgdat->node_id,
+					nodes);
+		else
+			return CONSTRAINT_CPUSET;
+
+	if (!nodes_empty(nodes))
+		return CONSTRAINT_MEMORY_POLICY;
+#endif
+
+	return CONSTRAINT_NONE;
+}
+
+/*
  * Simple selection loop. We chose the process with the highest
  * number of 'points'. We expect the caller will lock the tasklist.
  *
  * (not docbooked, we don't want this one cluttering up the manual)
  */
-static struct task_struct * select_bad_process(void)
+static struct task_struct *select_bad_process(unsigned long *ppoints)
 {
-	unsigned long maxpoints = 0;
 	struct task_struct *g, *p;
 	struct task_struct *chosen = NULL;
 	struct timespec uptime;
+	*ppoints = 0;
 
 	do_posix_clock_monotonic_gettime(&uptime);
 	do_each_thread(g, p) {
@@ -169,9 +201,9 @@ static struct task_struct * select_bad_process(void)
 			return p;
 
 		points = badness(p, uptime.tv_sec);
-		if (points > maxpoints || !chosen) {
+		if (points > *ppoints || !chosen) {
 			chosen = p;
-			maxpoints = points;
+			*ppoints = points;
 		}
 	} while_each_thread(g, p);
 	return chosen;
@@ -182,7 +214,7 @@ static struct task_struct * select_bad_process(void)
  * CAP_SYS_RAW_IO set, send SIGTERM instead (but it's unlikely that
  * we select a process with CAP_SYS_RAW_IO set).
  */
-static void __oom_kill_task(task_t *p)
+static void __oom_kill_task(task_t *p, const char *message)
 {
 	if (p->pid == 1) {
 		WARN_ON(1);
@@ -198,8 +230,8 @@ static void __oom_kill_task(task_t *p)
 		return;
 	}
 	task_unlock(p);
-	printk(KERN_ERR "Out of Memory: Killed process %d (%s).\n",
-							p->pid, p->comm);
+	printk(KERN_ERR "%s: Killed process %d (%s).\n",
+				message, p->pid, p->comm);
 
 	/*
 	 * We give our sacrificial lamb high priority and access to
@@ -212,7 +244,7 @@ static void __oom_kill_task(task_t *p)
 	force_sig(SIGKILL, p);
 }
 
-static struct mm_struct *oom_kill_task(task_t *p)
+static struct mm_struct *oom_kill_task(task_t *p, const char *message)
 {
 	struct mm_struct *mm = get_task_mm(p);
 	task_t * g, * q;
@@ -224,35 +256,38 @@ static struct mm_struct *oom_kill_task(task_t *p)
 		return NULL;
 	}
 
-	__oom_kill_task(p);
+	__oom_kill_task(p, message);
 	/*
 	 * kill all processes that share the ->mm (i.e. all threads),
 	 * but are in a different thread group
 	 */
 	do_each_thread(g, q)
 		if (q->mm == mm && q->tgid != p->tgid)
-			__oom_kill_task(q);
+			__oom_kill_task(q, message);
 	while_each_thread(g, q);
 
 	return mm;
 }
 
-static struct mm_struct *oom_kill_process(struct task_struct *p)
+static struct mm_struct *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;
 
+	printk(KERN_ERR "Out of Memory: Kill process %d (%s) score %li and "
+		"children.\n", p->pid, p->comm, points);
 	/* Try to kill a child first */
 	list_for_each(tsk, &p->children) {
 		c = list_entry(tsk, struct task_struct, sibling);
 		if (c->mm == p->mm)
 			continue;
-		mm = oom_kill_task(c);
+		mm = oom_kill_task(c, message);
 		if (mm)
 			return mm;
 	}
-	return oom_kill_task(p);
+	return oom_kill_task(p, message);
 }
 
 /**
@@ -263,10 +298,11 @@ static struct mm_struct *oom_kill_process(struct task_struct *p)
  * OR try to be smart about which process to kill. Note that we
  * don't have to be perfect here, we just have to be good.
  */
-void out_of_memory(gfp_t gfp_mask, int order)
+void out_of_memory(struct zonelist *zonelist, gfp_t gfp_mask, int order)
 {
 	struct mm_struct *mm = NULL;
-	task_t * p;
+	task_t *p;
+	unsigned long points;
 
 	if (printk_ratelimit()) {
 		printk("oom-killer: gfp_mask=0x%x, order=%d\n",
@@ -277,25 +313,48 @@ void out_of_memory(gfp_t gfp_mask, int order)
 
 	cpuset_lock();
 	read_lock(&tasklist_lock);
+
+	/*
+	 * Check if there were limitations on the allocation (only relevant for
+	 * NUMA) that may require different handling.
+	 */
+	switch (constrained_alloc(zonelist, gfp_mask)) {
+	case CONSTRAINT_MEMORY_POLICY:
+		mm = oom_kill_process(current, points,
+				"No available memory (MPOL_BIND)");
+		break;
+
+	case CONSTRAINT_CPUSET:
+		mm = oom_kill_process(current, points,
+				"No available memory in cpuset");
+		break;
+
+	case CONSTRAINT_NONE:
 retry:
-	p = select_bad_process();
+		/*
+		 * Rambo mode: Shoot down a process and hope it solves whatever
+		 * issues we may have.
+		 */
+		p = select_bad_process(&points);
 
-	if (PTR_ERR(p) == -1UL)
-		goto out;
+		if (PTR_ERR(p) == -1UL)
+			goto out;
 
-	/* Found nothing?!?! Either we hang forever, or we panic. */
-	if (!p) {
-		read_unlock(&tasklist_lock);
-		cpuset_unlock();
-		panic("Out of memory and no killable processes...\n");
-	}
+		/* Found nothing?!?! Either we hang forever, or we panic. */
+		if (!p) {
+			read_unlock(&tasklist_lock);
+			cpuset_unlock();
+			panic("Out of memory and no killable processes...\n");
+		}
 
-	mm = oom_kill_process(p);
-	if (!mm)
-		goto retry;
+		mm = oom_kill_process(p, points, "Out of memory");
+		if (!mm)
+			goto retry;
+
+		break;
+	}
 
- out:
-	read_unlock(&tasklist_lock);
+out:
 	cpuset_unlock();
 	if (mm)
 		mmput(mm);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 62c1225..791690d 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1015,7 +1015,7 @@ rebalance:
 		if (page)
 			goto got_pg;
 
-		out_of_memory(gfp_mask, order);
+		out_of_memory(zonelist, gfp_mask, order);
 		goto restart;
 	}
 
@@ -1541,29 +1541,29 @@ static int __initdata node_load[MAX_NUMNODES];
  */
 static int __init find_next_best_node(int node, nodemask_t *used_node_mask)
 {
-	int i, n, val;
+	int n, val;
 	int min_val = INT_MAX;
 	int best_node = -1;
 
-	for_each_online_node(i) {
-		cpumask_t tmp;
+	/* Use the local node if we haven't already */
+	if (!node_isset(node, *used_node_mask)) {
+		node_set(node, *used_node_mask);
+		return node;
+	}
 
-		/* Start from local node */
-		n = (node+i) % num_online_nodes();
+	for_each_online_node(n) {
+		cpumask_t tmp;
 
 		/* Don't want a node to appear more than once */
 		if (node_isset(n, *used_node_mask))
 			continue;
 
-		/* Use the local node if we haven't already */
-		if (!node_isset(node, *used_node_mask)) {
-			best_node = node;
-			break;
-		}
-
 		/* Use the distance array to find the distance */
 		val = node_distance(node, n);
 
+		/* Penalize nodes under us ("prefer the next node") */
+		val += (n < node);
+
 		/* Give preference to headless and unused nodes */
 		tmp = node_to_cpumask(n);
 		if (!cpus_empty(tmp))
diff --git a/mm/shmem.c b/mm/shmem.c
index f7ac7b8..7c455fb 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -45,6 +45,7 @@
 #include <linux/swapops.h>
 #include <linux/mempolicy.h>
 #include <linux/namei.h>
+#include <linux/ctype.h>
 #include <asm/uaccess.h>
 #include <asm/div64.h>
 #include <asm/pgtable.h>
@@ -874,6 +875,51 @@ redirty:
 }
 
 #ifdef CONFIG_NUMA
+static int shmem_parse_mpol(char *value, int *policy, nodemask_t *policy_nodes)
+{
+	char *nodelist = strchr(value, ':');
+	int err = 1;
+
+	if (nodelist) {
+		/* NUL-terminate policy string */
+		*nodelist++ = '\0';
+		if (nodelist_parse(nodelist, *policy_nodes))
+			goto out;
+	}
+	if (!strcmp(value, "default")) {
+		*policy = MPOL_DEFAULT;
+		/* Don't allow a nodelist */
+		if (!nodelist)
+			err = 0;
+	} else if (!strcmp(value, "prefer")) {
+		*policy = MPOL_PREFERRED;
+		/* Insist on a nodelist of one node only */
+		if (nodelist) {
+			char *rest = nodelist;
+			while (isdigit(*rest))
+				rest++;
+			if (!*rest)
+				err = 0;
+		}
+	} else if (!strcmp(value, "bind")) {
+		*policy = MPOL_BIND;
+		/* Insist on a nodelist */
+		if (nodelist)
+			err = 0;
+	} else if (!strcmp(value, "interleave")) {
+		*policy = MPOL_INTERLEAVE;
+		/* Default to nodes online if no nodelist */
+		if (!nodelist)
+			*policy_nodes = node_online_map;
+		err = 0;
+	}
+out:
+	/* Restore string for error message */
+	if (nodelist)
+		*--nodelist = ':';
+	return err;
+}
+
 static struct page *shmem_swapin_async(struct shared_policy *p,
 				       swp_entry_t entry, unsigned long idx)
 {
@@ -926,6 +972,11 @@ shmem_alloc_page(gfp_t gfp, struct shmem_inode_info *info,
 	return page;
 }
 #else
+static inline int shmem_parse_mpol(char *value, int *policy, nodemask_t *policy_nodes)
+{
+	return 1;
+}
+
 static inline struct page *
 shmem_swapin(struct shmem_inode_info *info,swp_entry_t entry,unsigned long idx)
 {
@@ -1859,7 +1910,23 @@ static int shmem_parse_options(char *options, int *mode, uid_t *uid,
 {
 	char *this_char, *value, *rest;
 
-	while ((this_char = strsep(&options, ",")) != NULL) {
+	while (options != NULL) {
+		this_char = options;
+		for (;;) {
+			/*
+			 * NUL-terminate this option: unfortunately,
+			 * mount options form a comma-separated list,
+			 * but mpol's nodelist may also contain commas.
+			 */
+			options = strchr(options, ',');
+			if (options == NULL)
+				break;
+			options++;
+			if (!isdigit(*options)) {
+				options[-1] = '\0';
+				break;
+			}
+		}
 		if (!*this_char)
 			continue;
 		if ((value = strchr(this_char,'=')) != NULL) {
@@ -1910,18 +1977,8 @@ static int shmem_parse_options(char *options, int *mode, uid_t *uid,
 			if (*rest)
 				goto bad_val;
 		} else if (!strcmp(this_char,"mpol")) {
-			if (!strcmp(value,"default"))
-				*policy = MPOL_DEFAULT;
-			else if (!strcmp(value,"preferred"))
-				*policy = MPOL_PREFERRED;
-			else if (!strcmp(value,"bind"))
-				*policy = MPOL_BIND;
-			else if (!strcmp(value,"interleave"))
-				*policy = MPOL_INTERLEAVE;
-			else
+			if (shmem_parse_mpol(value,policy,policy_nodes))
 				goto bad_val;
-		} else if (!strcmp(this_char,"mpol_nodelist")) {
-			nodelist_parse(value, *policy_nodes);
 		} else {
 			printk(KERN_ERR "tmpfs: Bad mount option %s\n",
 			       this_char);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 1838c15..b0af759 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1908,7 +1908,12 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
 		sc.swap_cluster_max = SWAP_CLUSTER_MAX;
 
 	cond_resched();
-	p->flags |= PF_MEMALLOC;
+	/*
+	 * We need to be able to allocate from the reserves for RECLAIM_SWAP
+	 * and we also need to be able to write out pages for RECLAIM_WRITE
+	 * and RECLAIM_SWAP.
+	 */
+	p->flags |= PF_MEMALLOC | PF_SWAPWRITE;
 	reclaim_state.reclaimed_slab = 0;
 	p->reclaim_state = &reclaim_state;
 
@@ -1932,11 +1937,10 @@ int zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
 		 * a long time.
 		 */
 		shrink_slab(sc.nr_scanned, gfp_mask, order);
-		sc.nr_reclaimed = 1;    /* Avoid getting the off node timeout */
 	}
 
 	p->reclaim_state = NULL;
-	current->flags &= ~PF_MEMALLOC;
+	current->flags &= ~(PF_MEMALLOC | PF_SWAPWRITE);
 
 	if (sc.nr_reclaimed == 0)
 		zone->last_unsuccessful_zone_reclaim = jiffies;