Revert "ANDROID: cpuset: Make cpusets restore on hotplug"

This reverts commit c8dc4422c6.  It causes
merge conflicts with 6.1-rc1.  If this is still needed in 6.1, it can
come back after 6.1-rc1 is merged.

Bug: 174125747
Bug: 120444281
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Amit Pundir <amit.pundir@linaro.org>
Cc: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I8b040cf6ba360aad710eb462aabf76d87e803b23

kernel/cgroup/cpuset.c

@@ -114,7 +114,6 @@ 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 */
@@ -485,7 +484,7 @@ 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_requested, q->cpus_requested) &&
+	return	cpumask_subset(p->cpus_allowed, q->cpus_allowed) &&
 		nodes_subset(p->mems_allowed, q->mems_allowed) &&
 		is_cpu_exclusive(p) <= is_cpu_exclusive(q) &&
 		is_mem_exclusive(p) <= is_mem_exclusive(q);
@@ -522,13 +521,8 @@ static inline int alloc_cpumasks(struct cpuset *cs, struct tmpmasks *tmp)
 	if (!zalloc_cpumask_var(pmask3, GFP_KERNEL))
 		goto free_two;
 
-	if (cs && !zalloc_cpumask_var(&cs->cpus_requested, GFP_KERNEL))
-		goto free_three;
-
 	return 0;
 
-free_three:
-	free_cpumask_var(*pmask3);
 free_two:
 	free_cpumask_var(*pmask2);
 free_one:
@@ -545,7 +539,6 @@ static inline void free_cpumasks(struct cpuset *cs, struct tmpmasks *tmp)
 {
 	if (cs) {
 		free_cpumask_var(cs->cpus_allowed);
-		free_cpumask_var(cs->cpus_requested);
 		free_cpumask_var(cs->effective_cpus);
 		free_cpumask_var(cs->subparts_cpus);
 	}
@@ -574,7 +567,6 @@ static struct cpuset *alloc_trial_cpuset(struct cpuset *cs)
 	}
 
 	cpumask_copy(trial->cpus_allowed, cs->cpus_allowed);
-	cpumask_copy(trial->cpus_requested, cs->cpus_requested);
 	cpumask_copy(trial->effective_cpus, cs->effective_cpus);
 	return trial;
 }
@@ -665,7 +657,7 @@ 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_requested, c->cpus_requested))
+		    cpumask_intersects(trial->cpus_allowed, c->cpus_allowed))
 			goto out;
 		if ((is_mem_exclusive(trial) || is_mem_exclusive(c)) &&
 		    c != cur &&
@@ -1162,10 +1154,10 @@ static void compute_effective_cpumask(struct cpumask *new_cpus,
 	if (parent->nr_subparts_cpus) {
 		cpumask_or(new_cpus, parent->effective_cpus,
 			   parent->subparts_cpus);
-		cpumask_and(new_cpus, new_cpus, cs->cpus_requested);
+		cpumask_and(new_cpus, new_cpus, cs->cpus_allowed);
 		cpumask_and(new_cpus, new_cpus, cpu_active_mask);
 	} else {
-		cpumask_and(new_cpus, cs->cpus_requested, parent_cs(cs)->effective_cpus);
+		cpumask_and(new_cpus, cs->cpus_allowed, parent->effective_cpus);
 	}
 }
 
@@ -1605,26 +1597,25 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
 		return -EACCES;
 
 	/*
-	 * An empty cpus_requested is ok only if the cpuset has no tasks.
+	 * An empty cpus_allowed is ok only if the cpuset has no tasks.
 	 * Since cpulist_parse() fails on an empty mask, we special case
 	 * that parsing.  The validate_change() call ensures that cpusets
 	 * with tasks have cpus.
 	 */
 	if (!*buf) {
-		cpumask_clear(trialcs->cpus_requested);
+		cpumask_clear(trialcs->cpus_allowed);
 	} else {
-		retval = cpulist_parse(buf, trialcs->cpus_requested);
+		retval = cpulist_parse(buf, trialcs->cpus_allowed);
 		if (retval < 0)
 			return retval;
+
+		if (!cpumask_subset(trialcs->cpus_allowed,
+				    top_cpuset.cpus_allowed))
+			return -EINVAL;
 	}
 
-	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_requested, trialcs->cpus_requested))
+	if (cpumask_equal(cs->cpus_allowed, trialcs->cpus_allowed))
 		return 0;
 
 	retval = validate_change(cs, trialcs);
@@ -1652,7 +1643,6 @@ 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);
 
 	/*
 	 * Make sure that subparts_cpus is a subset of cpus_allowed.
@@ -2540,7 +2530,7 @@ 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_requested));
+		seq_printf(sf, "%*pbl\n", cpumask_pr_args(cs->cpus_allowed));
 		break;
 	case FILE_MEMLIST:
 		seq_printf(sf, "%*pbl\n", nodemask_pr_args(&cs->mems_allowed));
@@ -2914,7 +2904,6 @@ 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:
@@ -3031,10 +3020,8 @@ int __init cpuset_init(void)
 	BUG_ON(!alloc_cpumask_var(&top_cpuset.cpus_allowed, GFP_KERNEL));
 	BUG_ON(!alloc_cpumask_var(&top_cpuset.effective_cpus, GFP_KERNEL));
 	BUG_ON(!zalloc_cpumask_var(&top_cpuset.subparts_cpus, GFP_KERNEL));
-	BUG_ON(!alloc_cpumask_var(&top_cpuset.cpus_requested, GFP_KERNEL));
 
 	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);