X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=kernel%2Fcpuset.c;h=3f9db31c5d043287b7e566fdaace6446ee46e6a1;hb=19e1695794ad1815c6b5f696c484c66354d4cafe;hp=b9279a2844d81656115195235df679ff2b2291e0;hpb=29bd03596e9511fa2f1a199d3a7603da28b32899;p=firefly-linux-kernel-4.4.55.git

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index b9279a2844d8..3f9db31c5d04 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -98,6 +98,7 @@ struct cpuset {
 
 	/* user-configured CPUs and Memory Nodes allow to tasks */
 	cpumask_var_t cpus_allowed;
+	cpumask_var_t cpus_requested;
 	nodemask_t mems_allowed;
 
 	/* effective CPUs and Memory Nodes allow to tasks */
@@ -324,8 +325,7 @@ static struct file_system_type cpuset_fs_type = {
 /*
  * Return in pmask the portion of a cpusets's cpus_allowed that
  * are online.  If none are online, walk up the cpuset hierarchy
- * until we find one that does have some online cpus.  The top
- * cpuset always has some cpus online.
+ * until we find one that does have some online cpus.
  *
  * One way or another, we guarantee to return some non-empty subset
  * of cpu_online_mask.
@@ -334,8 +334,20 @@ static struct file_system_type cpuset_fs_type = {
  */
 static void guarantee_online_cpus(struct cpuset *cs, struct cpumask *pmask)
 {
-	while (!cpumask_intersects(cs->effective_cpus, cpu_online_mask))
+	while (!cpumask_intersects(cs->effective_cpus, cpu_online_mask)) {
 		cs = parent_cs(cs);
+		if (unlikely(!cs)) {
+			/*
+			 * The top cpuset doesn't have any online cpu as a
+			 * consequence of a race between cpuset_hotplug_work
+			 * and cpu hotplug notifier.  But we know the top
+			 * cpuset's effective_cpus is on its way to to be
+			 * identical to cpu_online_mask.
+			 */
+			cpumask_copy(pmask, cpu_online_mask);
+			return;
+		}
+	}
 	cpumask_and(pmask, cs->effective_cpus, cpu_online_mask);
 }
 
@@ -386,7 +398,7 @@ static void cpuset_update_task_spread_flag(struct cpuset *cs,
 
 static int is_cpuset_subset(const struct cpuset *p, const struct cpuset *q)
 {
-	return	cpumask_subset(p->cpus_allowed, q->cpus_allowed) &&
+	return	cpumask_subset(p->cpus_requested, q->cpus_requested) &&
 		nodes_subset(p->mems_allowed, q->mems_allowed) &&
 		is_cpu_exclusive(p) <= is_cpu_exclusive(q) &&
 		is_mem_exclusive(p) <= is_mem_exclusive(q);
@@ -486,7 +498,7 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
 	cpuset_for_each_child(c, css, par) {
 		if ((is_cpu_exclusive(trial) || is_cpu_exclusive(c)) &&
 		    c != cur &&
-		    cpumask_intersects(trial->cpus_allowed, c->cpus_allowed))
+		    cpumask_intersects(trial->cpus_requested, c->cpus_requested))
 			goto out;
 		if ((is_mem_exclusive(trial) || is_mem_exclusive(c)) &&
 		    c != cur &&
@@ -945,17 +957,18 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
 	if (!*buf) {
 		cpumask_clear(trialcs->cpus_allowed);
 	} else {
-		retval = cpulist_parse(buf, trialcs->cpus_allowed);
+		retval = cpulist_parse(buf, trialcs->cpus_requested);
 		if (retval < 0)
 			return retval;
 
-		if (!cpumask_subset(trialcs->cpus_allowed,
-				    top_cpuset.cpus_allowed))
+		if (!cpumask_subset(trialcs->cpus_requested, cpu_present_mask))
 			return -EINVAL;
+
+		cpumask_and(trialcs->cpus_allowed, trialcs->cpus_requested, cpu_active_mask);
 	}
 
 	/* Nothing to do if the cpus didn't change */
-	if (cpumask_equal(cs->cpus_allowed, trialcs->cpus_allowed))
+	if (cpumask_equal(cs->cpus_requested, trialcs->cpus_requested))
 		return 0;
 
 	retval = validate_change(cs, trialcs);
@@ -964,6 +977,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
 
 	spin_lock_irq(&callback_lock);
 	cpumask_copy(cs->cpus_allowed, trialcs->cpus_allowed);
+	cpumask_copy(cs->cpus_requested, trialcs->cpus_requested);
 	spin_unlock_irq(&callback_lock);
 
 	/* use trialcs->cpus_allowed as a temp variable */
@@ -1754,7 +1768,7 @@ static int cpuset_common_seq_show(struct seq_file *sf, void *v)
 
 	switch (type) {
 	case FILE_CPULIST:
-		seq_printf(sf, "%*pbl\n", cpumask_pr_args(cs->cpus_allowed));
+		seq_printf(sf, "%*pbl\n", cpumask_pr_args(cs->cpus_requested));
 		break;
 	case FILE_MEMLIST:
 		seq_printf(sf, "%*pbl\n", nodemask_pr_args(&cs->mems_allowed));
@@ -1943,11 +1957,14 @@ cpuset_css_alloc(struct cgroup_subsys_state *parent_css)
 		return ERR_PTR(-ENOMEM);
 	if (!alloc_cpumask_var(&cs->cpus_allowed, GFP_KERNEL))
 		goto free_cs;
+	if (!alloc_cpumask_var(&cs->cpus_requested, GFP_KERNEL))
+		goto free_allowed;
 	if (!alloc_cpumask_var(&cs->effective_cpus, GFP_KERNEL))
-		goto free_cpus;
+		goto free_requested;
 
 	set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);
 	cpumask_clear(cs->cpus_allowed);
+	cpumask_clear(cs->cpus_requested);
 	nodes_clear(cs->mems_allowed);
 	cpumask_clear(cs->effective_cpus);
 	nodes_clear(cs->effective_mems);
@@ -1956,7 +1973,9 @@ cpuset_css_alloc(struct cgroup_subsys_state *parent_css)
 
 	return &cs->css;
 
-free_cpus:
+free_requested:
+	free_cpumask_var(cs->cpus_requested);
+free_allowed:
 	free_cpumask_var(cs->cpus_allowed);
 free_cs:
 	kfree(cs);
@@ -2019,6 +2038,7 @@ static int cpuset_css_online(struct cgroup_subsys_state *css)
 	cs->mems_allowed = parent->mems_allowed;
 	cs->effective_mems = parent->mems_allowed;
 	cpumask_copy(cs->cpus_allowed, parent->cpus_allowed);
+	cpumask_copy(cs->cpus_requested, parent->cpus_requested);
 	cpumask_copy(cs->effective_cpus, parent->cpus_allowed);
 	spin_unlock_irq(&callback_lock);
 out_unlock:
@@ -2053,6 +2073,7 @@ static void cpuset_css_free(struct cgroup_subsys_state *css)
 
 	free_cpumask_var(cs->effective_cpus);
 	free_cpumask_var(cs->cpus_allowed);
+	free_cpumask_var(cs->cpus_requested);
 	kfree(cs);
 }
 
@@ -2117,8 +2138,11 @@ int __init cpuset_init(void)
 		BUG();
 	if (!alloc_cpumask_var(&top_cpuset.effective_cpus, GFP_KERNEL))
 		BUG();
+	if (!alloc_cpumask_var(&top_cpuset.cpus_requested, GFP_KERNEL))
+		BUG();
 
 	cpumask_setall(top_cpuset.cpus_allowed);
+	cpumask_setall(top_cpuset.cpus_requested);
 	nodes_setall(top_cpuset.mems_allowed);
 	cpumask_setall(top_cpuset.effective_cpus);
 	nodes_setall(top_cpuset.effective_mems);
@@ -2252,7 +2276,7 @@ retry:
 		goto retry;
 	}
 
-	cpumask_and(&new_cpus, cs->cpus_allowed, parent_cs(cs)->effective_cpus);
+	cpumask_and(&new_cpus, cs->cpus_requested, parent_cs(cs)->effective_cpus);
 	nodes_and(new_mems, cs->mems_allowed, parent_cs(cs)->effective_mems);
 
 	cpus_updated = !cpumask_equal(&new_cpus, cs->effective_cpus);