1 files changed, 41 insertions, 101 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 57e6448b171..0864f409793 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -581,26 +581,28 @@ static void guarantee_online_cpus(const struct cpuset *cs, cpumask_t *pmask)
 
 /*
  * Return in *pmask the portion of a cpusets's mems_allowed that
- * are online.  If none are online, walk up the cpuset hierarchy
- * until we find one that does have some online mems.  If we get
- * all the way to the top and still haven't found any online mems,
- * return node_online_map.
+ * are online, with memory.  If none are online with memory, walk
+ * up the cpuset hierarchy until we find one that does have some
+ * online mems.  If we get all the way to the top and still haven't
+ * found any online mems, return node_states[N_HIGH_MEMORY].
  *
  * One way or another, we guarantee to return some non-empty subset
- * of node_online_map.
+ * of node_states[N_HIGH_MEMORY].
  *
  * Call with callback_mutex held.
  */
 
 static void guarantee_online_mems(const struct cpuset *cs, nodemask_t *pmask)
 {
-	while (cs && !nodes_intersects(cs->mems_allowed, node_online_map))
+	while (cs && !nodes_intersects(cs->mems_allowed,
+					node_states[N_HIGH_MEMORY]))
 		cs = cs->parent;
 	if (cs)
-		nodes_and(*pmask, cs->mems_allowed, node_online_map);
+		nodes_and(*pmask, cs->mems_allowed,
+					node_states[N_HIGH_MEMORY]);
 	else
-		*pmask = node_online_map;
-	BUG_ON(!nodes_intersects(*pmask, node_online_map));
+		*pmask = node_states[N_HIGH_MEMORY];
+	BUG_ON(!nodes_intersects(*pmask, node_states[N_HIGH_MEMORY]));
 }
 
 /**
@@ -753,68 +755,13 @@ static int validate_change(const struct cpuset *cur, const struct cpuset *trial)
 }
 
 /*
- * For a given cpuset cur, partition the system as follows
- * a. All cpus in the parent cpuset's cpus_allowed that are not part of any
- *    exclusive child cpusets
- * b. All cpus in the current cpuset's cpus_allowed that are not part of any
- *    exclusive child cpusets
- * Build these two partitions by calling partition_sched_domains
- *
- * Call with manage_mutex held.  May nest a call to the
- * lock_cpu_hotplug()/unlock_cpu_hotplug() pair.
- * Must not be called holding callback_mutex, because we must
- * not call lock_cpu_hotplug() while holding callback_mutex.
- */
-
-static void update_cpu_domains(struct cpuset *cur)
-{
-	struct cpuset *c, *par = cur->parent;
-	cpumask_t pspan, cspan;
-
-	if (par == NULL || cpus_empty(cur->cpus_allowed))
-		return;
-
-	/*
-	 * Get all cpus from parent's cpus_allowed not part of exclusive
-	 * children
-	 */
-	pspan = par->cpus_allowed;
-	list_for_each_entry(c, &par->children, sibling) {
-		if (is_cpu_exclusive(c))
-			cpus_andnot(pspan, pspan, c->cpus_allowed);
-	}
-	if (!is_cpu_exclusive(cur)) {
-		cpus_or(pspan, pspan, cur->cpus_allowed);
-		if (cpus_equal(pspan, cur->cpus_allowed))
-			return;
-		cspan = CPU_MASK_NONE;
-	} else {
-		if (cpus_empty(pspan))
-			return;
-		cspan = cur->cpus_allowed;
-		/*
-		 * Get all cpus from current cpuset's cpus_allowed not part
-		 * of exclusive children
-		 */
-		list_for_each_entry(c, &cur->children, sibling) {
-			if (is_cpu_exclusive(c))
-				cpus_andnot(cspan, cspan, c->cpus_allowed);
-		}
-	}
-
-	lock_cpu_hotplug();
-	partition_sched_domains(&pspan, &cspan);
-	unlock_cpu_hotplug();
-}
-
-/*
  * Call with manage_mutex held.  May take callback_mutex during call.
  */
 
 static int update_cpumask(struct cpuset *cs, char *buf)
 {
 	struct cpuset trialcs;
-	int retval, cpus_unchanged;
+	int retval;
 
 	/* top_cpuset.cpus_allowed tracks cpu_online_map; it's read-only */
 	if (cs == &top_cpuset)
@@ -841,12 +788,9 @@ static int update_cpumask(struct cpuset *cs, char *buf)
 	retval = validate_change(cs, &trialcs);
 	if (retval < 0)
 		return retval;
-	cpus_unchanged = cpus_equal(cs->cpus_allowed, trialcs.cpus_allowed);
 	mutex_lock(&callback_mutex);
 	cs->cpus_allowed = trialcs.cpus_allowed;
 	mutex_unlock(&callback_mutex);
-	if (is_cpu_exclusive(cs) && !cpus_unchanged)
-		update_cpu_domains(cs);
 	return 0;
 }
 
@@ -924,7 +868,10 @@ static int update_nodemask(struct cpuset *cs, char *buf)
 	int fudge;
 	int retval;
 
-	/* top_cpuset.mems_allowed tracks node_online_map; it's read-only */
+	/*
+	 * top_cpuset.mems_allowed tracks node_stats[N_HIGH_MEMORY];
+	 * it's read-only
+	 */
 	if (cs == &top_cpuset)
 		return -EACCES;
 
@@ -941,8 +888,21 @@ static int update_nodemask(struct cpuset *cs, char *buf)
 		retval = nodelist_parse(buf, trialcs.mems_allowed);
 		if (retval < 0)
 			goto done;
+		if (!nodes_intersects(trialcs.mems_allowed,
+						node_states[N_HIGH_MEMORY])) {
+			/*
+			 * error if only memoryless nodes specified.
+			 */
+			retval = -ENOSPC;
+			goto done;
+		}
 	}
-	nodes_and(trialcs.mems_allowed, trialcs.mems_allowed, node_online_map);
+	/*
+	 * Exclude memoryless nodes.  We know that trialcs.mems_allowed
+	 * contains at least one node with memory.
+	 */
+	nodes_and(trialcs.mems_allowed, trialcs.mems_allowed,
+						node_states[N_HIGH_MEMORY]);
 	oldmem = cs->mems_allowed;
 	if (nodes_equal(oldmem, trialcs.mems_allowed)) {
 		retval = 0;		/* Too easy - nothing to do */
@@ -1067,7 +1027,7 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, char *buf)
 {
 	int turning_on;
 	struct cpuset trialcs;
-	int err, cpu_exclusive_changed;
+	int err;
 
 	turning_on = (simple_strtoul(buf, NULL, 10) != 0);
 
@@ -1080,14 +1040,10 @@ static int update_flag(cpuset_flagbits_t bit, struct cpuset *cs, char *buf)
 	err = validate_change(cs, &trialcs);
 	if (err < 0)
 		return err;
-	cpu_exclusive_changed =
-		(is_cpu_exclusive(cs) != is_cpu_exclusive(&trialcs));
 	mutex_lock(&callback_mutex);
 	cs->flags = trialcs.flags;
 	mutex_unlock(&callback_mutex);
 
-	if (cpu_exclusive_changed)
-                update_cpu_domains(cs);
 	return 0;
 }
 
@@ -1445,7 +1401,7 @@ static ssize_t cpuset_common_file_read(struct file *file, char __user *buf,
 	ssize_t retval = 0;
 	char *s;
 
-	if (!(page = (char *)__get_free_page(GFP_KERNEL)))
+	if (!(page = (char *)__get_free_page(GFP_TEMPORARY)))
 		return -ENOMEM;
 
 	s = page;
@@ -1947,17 +1903,6 @@ static int cpuset_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 	return cpuset_create(c_parent, dentry->d_name.name, mode | S_IFDIR);
 }
 
-/*
- * Locking note on the strange update_flag() call below:
- *
- * If the cpuset being removed is marked cpu_exclusive, then simulate
- * turning cpu_exclusive off, which will call update_cpu_domains().
- * The lock_cpu_hotplug() call in update_cpu_domains() must not be
- * made while holding callback_mutex.  Elsewhere the kernel nests
- * callback_mutex inside lock_cpu_hotplug() calls.  So the reverse
- * nesting would risk an ABBA deadlock.
- */
-
 static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry)
 {
 	struct cpuset *cs = dentry->d_fsdata;
@@ -1977,13 +1922,6 @@ static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry)
 		mutex_unlock(&manage_mutex);
 		return -EBUSY;
 	}
-	if (is_cpu_exclusive(cs)) {
-		int retval = update_flag(CS_CPU_EXCLUSIVE, cs, "0");
-		if (retval < 0) {
-			mutex_unlock(&manage_mutex);
-			return retval;
-		}
-	}
 	parent = cs->parent;
 	mutex_lock(&callback_mutex);
 	set_bit(CS_REMOVED, &cs->flags);
@@ -2098,8 +2036,9 @@ static void guarantee_online_cpus_mems_in_subtree(const struct cpuset *cur)
 
 /*
  * The cpus_allowed and mems_allowed nodemasks in the top_cpuset track
- * cpu_online_map and node_online_map.  Force the top cpuset to track
- * whats online after any CPU or memory node hotplug or unplug event.
+ * cpu_online_map and node_states[N_HIGH_MEMORY].  Force the top cpuset to
+ * track what's online after any CPU or memory node hotplug or unplug
+ * event.
  *
  * To ensure that we don't remove a CPU or node from the top cpuset
  * that is currently in use by a child cpuset (which would violate
@@ -2119,7 +2058,7 @@ static void common_cpu_mem_hotplug_unplug(void)
 
 	guarantee_online_cpus_mems_in_subtree(&top_cpuset);
 	top_cpuset.cpus_allowed = cpu_online_map;
-	top_cpuset.mems_allowed = node_online_map;
+	top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
 
 	mutex_unlock(&callback_mutex);
 	mutex_unlock(&manage_mutex);
@@ -2147,8 +2086,9 @@ static int cpuset_handle_cpuhp(struct notifier_block *nb,
 
 #ifdef CONFIG_MEMORY_HOTPLUG
 /*
- * Keep top_cpuset.mems_allowed tracking node_online_map.
- * Call this routine anytime after you change node_online_map.
+ * Keep top_cpuset.mems_allowed tracking node_states[N_HIGH_MEMORY].
+ * Call this routine anytime after you change
+ * node_states[N_HIGH_MEMORY].
  * See also the previous routine cpuset_handle_cpuhp().
  */
 
@@ -2167,7 +2107,7 @@ void cpuset_track_online_nodes(void)
 void __init cpuset_init_smp(void)
 {
 	top_cpuset.cpus_allowed = cpu_online_map;
-	top_cpuset.mems_allowed = node_online_map;
+	top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];
 
 	hotcpu_notifier(cpuset_handle_cpuhp, 0);
 }
@@ -2309,7 +2249,7 @@ void cpuset_init_current_mems_allowed(void)
  *
  * Description: Returns the nodemask_t mems_allowed of the cpuset
  * attached to the specified @tsk.  Guaranteed to return some non-empty
- * subset of node_online_map, even if this means going outside the
+ * subset of node_states[N_HIGH_MEMORY], even if this means going outside the
  * tasks cpuset.
  **/