Commit 6ca09dfc authored by Mike Travis's avatar Mike Travis Committed by Ingo Molnar
Browse files

sched: put back some stack hog changes that were undone in kernel/sched.c 



Impact: prevents panic from stack overflow on numa-capable machines.

Some of the "removal of stack hogs" changes in kernel/sched.c by using
node_to_cpumask_ptr were undone by the early cpumask API updates, and
causes a panic due to stack overflow.  This patch undoes those changes
by using cpumask_of_node() which returns a 'const struct cpumask *'.

In addition, cpu_coregoup_map is replaced with cpu_coregroup_mask further
reducing stack usage.  (Both of these updates removed 9 FIXME's!)

Also:
   Pick up some remaining changes from the old 'cpumask_t' functions to
   the new 'struct cpumask *' functions.

   Optimize memory traffic by allocating each percpu local_cpu_mask on the
   same node as the referring cpu.

Signed-off-by: default avatarMike Travis <travis@sgi.com>
Acked-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 730cf272

kernel/sched.c

+15 −38
Original line number Diff line number Diff line
@@ -3715,7 +3715,7 @@ redo: 
		 * don't kick the migration_thread, if the curr

		 * task on busiest cpu can't be moved to this_cpu

		 */

		if (!cpu_isset(this_cpu, busiest->curr->cpus_allowed)) {

		if (!cpumask_test_cpu(this_cpu, &busiest->curr->cpus_allowed)) {

			double_unlock_balance(this_rq, busiest);

			all_pinned = 1;

			return ld_moved;
@@ -6220,9 +6220,7 @@ static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu) 
static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p)

{

	int dest_cpu;

	/* FIXME: Use cpumask_of_node here. */

	cpumask_t _nodemask = node_to_cpumask(cpu_to_node(dead_cpu));

	const struct cpumask *nodemask = &_nodemask;

	const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(dead_cpu));



again:

	/* Look for allowed, online CPU in same node. */
@@ -7133,21 +7131,18 @@ static int find_next_best_node(int node, nodemask_t *used_nodes) 
static void sched_domain_node_span(int node, struct cpumask *span)

{

	nodemask_t used_nodes;

	/* FIXME: use cpumask_of_node() */

	node_to_cpumask_ptr(nodemask, node);

	int i;



	cpus_clear(*span);

	cpumask_clear(span);

	nodes_clear(used_nodes);



	cpus_or(*span, *span, *nodemask);

	cpumask_or(span, span, cpumask_of_node(node));

	node_set(node, used_nodes);



	for (i = 1; i < SD_NODES_PER_DOMAIN; i++) {

		int next_node = find_next_best_node(node, &used_nodes);



		node_to_cpumask_ptr_next(nodemask, next_node);

		cpus_or(*span, *span, *nodemask);

		cpumask_or(span, span, cpumask_of_node(next_node));

	}

}

#endif /* CONFIG_NUMA */
@@ -7227,9 +7222,7 @@ cpu_to_phys_group(int cpu, const struct cpumask *cpu_map, 
{

	int group;

#ifdef CONFIG_SCHED_MC

	/* FIXME: Use cpu_coregroup_mask. */

	*mask = cpu_coregroup_map(cpu);

	cpus_and(*mask, *mask, *cpu_map);

	cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map);

	group = cpumask_first(mask);

#elif defined(CONFIG_SCHED_SMT)

	cpumask_and(mask, &per_cpu(cpu_sibling_map, cpu), cpu_map);
@@ -7259,10 +7252,8 @@ static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map, 
				 struct cpumask *nodemask)

{

	int group;

	/* FIXME: use cpumask_of_node */

	node_to_cpumask_ptr(pnodemask, cpu_to_node(cpu));



	cpumask_and(nodemask, pnodemask, cpu_map);

	cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map);

	group = cpumask_first(nodemask);



	if (sg)
@@ -7313,10 +7304,8 @@ static void free_sched_groups(const struct cpumask *cpu_map, 


		for (i = 0; i < nr_node_ids; i++) {

			struct sched_group *oldsg, *sg = sched_group_nodes[i];

			/* FIXME: Use cpumask_of_node */

			node_to_cpumask_ptr(pnodemask, i);



			cpus_and(*nodemask, *pnodemask, *cpu_map);

			cpumask_and(nodemask, cpumask_of_node(i), cpu_map);

			if (cpumask_empty(nodemask))

				continue;
@@ -7525,9 +7514,7 @@ static int __build_sched_domains(const struct cpumask *cpu_map, 
	for_each_cpu(i, cpu_map) {

		struct sched_domain *sd = NULL, *p;



		/* FIXME: use cpumask_of_node */

		*nodemask = node_to_cpumask(cpu_to_node(i));

		cpus_and(*nodemask, *nodemask, *cpu_map);

		cpumask_and(nodemask, cpumask_of_node(cpu_to_node(i)), cpu_map);



#ifdef CONFIG_NUMA

		if (cpumask_weight(cpu_map) >
@@ -7568,9 +7555,8 @@ static int __build_sched_domains(const struct cpumask *cpu_map, 
		sd = &per_cpu(core_domains, i).sd;

		SD_INIT(sd, MC);

		set_domain_attribute(sd, attr);

		*sched_domain_span(sd) = cpu_coregroup_map(i);

		cpumask_and(sched_domain_span(sd),

			    sched_domain_span(sd), cpu_map);

		cpumask_and(sched_domain_span(sd), cpu_map,

						   cpu_coregroup_mask(i));

		sd->parent = p;

		p->child = sd;

		cpu_to_core_group(i, cpu_map, &sd->groups, tmpmask);
@@ -7606,9 +7592,7 @@ static int __build_sched_domains(const struct cpumask *cpu_map, 
#ifdef CONFIG_SCHED_MC

	/* Set up multi-core groups */

	for_each_cpu(i, cpu_map) {

		/* FIXME: Use cpu_coregroup_mask */

		*this_core_map = cpu_coregroup_map(i);

		cpus_and(*this_core_map, *this_core_map, *cpu_map);

		cpumask_and(this_core_map, cpu_coregroup_mask(i), cpu_map);

		if (i != cpumask_first(this_core_map))

			continue;
@@ -7620,9 +7604,7 @@ static int __build_sched_domains(const struct cpumask *cpu_map, 


	/* Set up physical groups */

	for (i = 0; i < nr_node_ids; i++) {

		/* FIXME: Use cpumask_of_node */

		*nodemask = node_to_cpumask(i);

		cpus_and(*nodemask, *nodemask, *cpu_map);

		cpumask_and(nodemask, cpumask_of_node(i), cpu_map);

		if (cpumask_empty(nodemask))

			continue;
@@ -7644,11 +7626,8 @@ static int __build_sched_domains(const struct cpumask *cpu_map, 
		struct sched_group *sg, *prev;

		int j;



		/* FIXME: Use cpumask_of_node */

		*nodemask = node_to_cpumask(i);

		cpumask_clear(covered);



		cpus_and(*nodemask, *nodemask, *cpu_map);

		cpumask_and(nodemask, cpumask_of_node(i), cpu_map);

		if (cpumask_empty(nodemask)) {

			sched_group_nodes[i] = NULL;

			continue;
@@ -7679,8 +7658,6 @@ static int __build_sched_domains(const struct cpumask *cpu_map, 


		for (j = 0; j < nr_node_ids; j++) {

			int n = (i + j) % nr_node_ids;

			/* FIXME: Use cpumask_of_node */

			node_to_cpumask_ptr(pnodemask, n);



			cpumask_complement(notcovered, covered);

			cpumask_and(tmpmask, notcovered, cpu_map);
@@ -7688,7 +7665,7 @@ static int __build_sched_domains(const struct cpumask *cpu_map, 
			if (cpumask_empty(tmpmask))

				break;



			cpumask_and(tmpmask, tmpmask, pnodemask);

			cpumask_and(tmpmask, tmpmask, cpumask_of_node(n));

			if (cpumask_empty(tmpmask))

				continue;

kernel/sched_rt.c

+2 −1
Original line number Diff line number Diff line
@@ -1383,7 +1383,8 @@ static inline void init_sched_rt_class(void) 
	unsigned int i;



	for_each_possible_cpu(i)

		alloc_cpumask_var(&per_cpu(local_cpu_mask, i), GFP_KERNEL);

		alloc_cpumask_var_node(&per_cpu(local_cpu_mask, i),

					GFP_KERNEL, cpu_to_node(i));

}

#endif /* CONFIG_SMP */

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