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Commit 53feb297 authored by Miao Xie's avatar Miao Xie Committed by Linus Torvalds
Browse files

cpuset: alloc nodemask_t on the heap rather than the stack 



Signed-off-by: default avatarMiao Xie <miaox@cn.fujitsu.com>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5ab116c9

kernel/cpuset.c

+66 −28
Original line number Diff line number Diff line
@@ -970,15 +970,20 @@ static void cpuset_change_nodemask(struct task_struct *p, 
	struct cpuset *cs;

	int migrate;

	const nodemask_t *oldmem = scan->data;

	nodemask_t newmems;

	NODEMASK_ALLOC(nodemask_t, newmems, GFP_KERNEL);



	if (!newmems)

		return;



	cs = cgroup_cs(scan->cg);

	guarantee_online_mems(cs, &newmems);

	guarantee_online_mems(cs, newmems);



	task_lock(p);

	cpuset_change_task_nodemask(p, &newmems);

	cpuset_change_task_nodemask(p, newmems);

	task_unlock(p);



	NODEMASK_FREE(newmems);



	mm = get_task_mm(p);

	if (!mm)

		return;
@@ -1048,16 +1053,21 @@ static void update_tasks_nodemask(struct cpuset *cs, const nodemask_t *oldmem, 
static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs,

			   const char *buf)

{

	nodemask_t oldmem;

	NODEMASK_ALLOC(nodemask_t, oldmem, GFP_KERNEL);

	int retval;

	struct ptr_heap heap;



	if (!oldmem)

		return -ENOMEM;



	/*

	 * top_cpuset.mems_allowed tracks node_stats[N_HIGH_MEMORY];

	 * it's read-only

	 */

	if (cs == &top_cpuset)

		return -EACCES;

	if (cs == &top_cpuset) {

		retval = -EACCES;

		goto done;

	}



	/*

	 * An empty mems_allowed is ok iff there are no tasks in the cpuset.
@@ -1073,11 +1083,13 @@ static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs, 
			goto done;



		if (!nodes_subset(trialcs->mems_allowed,

				node_states[N_HIGH_MEMORY]))

			return -EINVAL;

				node_states[N_HIGH_MEMORY])) {

			retval =  -EINVAL;

			goto done;

		}

	oldmem = cs->mems_allowed;

	if (nodes_equal(oldmem, trialcs->mems_allowed)) {

	}

	*oldmem = cs->mems_allowed;

	if (nodes_equal(*oldmem, trialcs->mems_allowed)) {

		retval = 0;		/* Too easy - nothing to do */

		goto done;

	}
@@ -1093,10 +1105,11 @@ static int update_nodemask(struct cpuset *cs, struct cpuset *trialcs, 
	cs->mems_allowed = trialcs->mems_allowed;

	mutex_unlock(&callback_mutex);



	update_tasks_nodemask(cs, &oldmem, &heap);

	update_tasks_nodemask(cs, oldmem, &heap);



	heap_free(&heap);

done:

	NODEMASK_FREE(oldmem);

	return retval;

}
@@ -1381,39 +1394,47 @@ static void cpuset_attach(struct cgroup_subsys *ss, struct cgroup *cont, 
			  struct cgroup *oldcont, struct task_struct *tsk,

			  bool threadgroup)

{

	nodemask_t from, to;

	struct mm_struct *mm;

	struct cpuset *cs = cgroup_cs(cont);

	struct cpuset *oldcs = cgroup_cs(oldcont);

	NODEMASK_ALLOC(nodemask_t, from, GFP_KERNEL);

	NODEMASK_ALLOC(nodemask_t, to, GFP_KERNEL);



	if (from == NULL || to == NULL)

		goto alloc_fail;



	if (cs == &top_cpuset) {

		cpumask_copy(cpus_attach, cpu_possible_mask);

	} else {

		guarantee_online_cpus(cs, cpus_attach);

	}

	guarantee_online_mems(cs, &to);

	guarantee_online_mems(cs, to);



	/* do per-task migration stuff possibly for each in the threadgroup */

	cpuset_attach_task(tsk, &to, cs);

	cpuset_attach_task(tsk, to, cs);

	if (threadgroup) {

		struct task_struct *c;

		rcu_read_lock();

		list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) {

			cpuset_attach_task(c, &to, cs);

			cpuset_attach_task(c, to, cs);

		}

		rcu_read_unlock();

	}



	/* change mm; only needs to be done once even if threadgroup */

	from = oldcs->mems_allowed;

	to = cs->mems_allowed;

	*from = oldcs->mems_allowed;

	*to = cs->mems_allowed;

	mm = get_task_mm(tsk);

	if (mm) {

		mpol_rebind_mm(mm, &to);

		mpol_rebind_mm(mm, to);

		if (is_memory_migrate(cs))

			cpuset_migrate_mm(mm, &from, &to);

			cpuset_migrate_mm(mm, from, to);

		mmput(mm);

	}



alloc_fail:

	NODEMASK_FREE(from);

	NODEMASK_FREE(to);

}



/* The various types of files and directories in a cpuset file system */
@@ -1558,13 +1579,21 @@ static int cpuset_sprintf_cpulist(char *page, struct cpuset *cs) 


static int cpuset_sprintf_memlist(char *page, struct cpuset *cs)

{

	nodemask_t mask;

	NODEMASK_ALLOC(nodemask_t, mask, GFP_KERNEL);

	int retval;



	if (mask == NULL)

		return -ENOMEM;



	mutex_lock(&callback_mutex);

	mask = cs->mems_allowed;

	*mask = cs->mems_allowed;

	mutex_unlock(&callback_mutex);



	return nodelist_scnprintf(page, PAGE_SIZE, mask);

	retval = nodelist_scnprintf(page, PAGE_SIZE, *mask);



	NODEMASK_FREE(mask);



	return retval;

}



static ssize_t cpuset_common_file_read(struct cgroup *cont,
@@ -1993,7 +2022,10 @@ static void scan_for_empty_cpusets(struct cpuset *root) 
	struct cpuset *cp;	/* scans cpusets being updated */

	struct cpuset *child;	/* scans child cpusets of cp */

	struct cgroup *cont;

	nodemask_t oldmems;

	NODEMASK_ALLOC(nodemask_t, oldmems, GFP_KERNEL);



	if (oldmems == NULL)

		return;



	list_add_tail((struct list_head *)&root->stack_list, &queue);
@@ -2010,7 +2042,7 @@ static void scan_for_empty_cpusets(struct cpuset *root) 
		    nodes_subset(cp->mems_allowed, node_states[N_HIGH_MEMORY]))

			continue;



		oldmems = cp->mems_allowed;

		*oldmems = cp->mems_allowed;



		/* Remove offline cpus and mems from this cpuset. */

		mutex_lock(&callback_mutex);
@@ -2026,9 +2058,10 @@ static void scan_for_empty_cpusets(struct cpuset *root) 
			remove_tasks_in_empty_cpuset(cp);

		else {

			update_tasks_cpumask(cp, NULL);

			update_tasks_nodemask(cp, &oldmems, NULL);

			update_tasks_nodemask(cp, oldmems, NULL);

		}

	}

	NODEMASK_FREE(oldmems);

}



/*
@@ -2086,16 +2119,19 @@ static int cpuset_track_online_cpus(struct notifier_block *unused_nb, 
static int cpuset_track_online_nodes(struct notifier_block *self,

				unsigned long action, void *arg)

{

	nodemask_t oldmems;

	NODEMASK_ALLOC(nodemask_t, oldmems, GFP_KERNEL);



	if (oldmems == NULL)

		return NOTIFY_DONE;



	cgroup_lock();

	switch (action) {

	case MEM_ONLINE:

		oldmems = top_cpuset.mems_allowed;

		*oldmems = top_cpuset.mems_allowed;

		mutex_lock(&callback_mutex);

		top_cpuset.mems_allowed = node_states[N_HIGH_MEMORY];

		mutex_unlock(&callback_mutex);

		update_tasks_nodemask(&top_cpuset, &oldmems, NULL);

		update_tasks_nodemask(&top_cpuset, oldmems, NULL);

		break;

	case MEM_OFFLINE:

		/*
@@ -2108,6 +2144,8 @@ static int cpuset_track_online_nodes(struct notifier_block *self, 
		break;

	}

	cgroup_unlock();



	NODEMASK_FREE(oldmems);

	return NOTIFY_OK;

}

#endif