Commit c8f699bb authored by Tejun Heo's avatar Tejun Heo
Browse files

cpuset: introduce ->css_on/offline() 



Add cpuset_css_on/offline() and rearrange css init/exit such that,

* Allocation and clearing to the default values happen in css_alloc().
  Allocation now uses kzalloc().

* Config inheritance and registration happen in css_online().

* css_offline() undoes what css_online() did.

* css_free() frees.

This doesn't introduce any visible behavior changes.  This will help
cleaning up locking.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarLi Zefan <lizefan@huawei.com>
parent 0772324a

kernel/cpuset.c

+44 −22
Original line number Diff line number Diff line
@@ -1790,15 +1790,12 @@ static struct cftype files[] = { 


static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cont)

{

	struct cgroup *parent_cg = cont->parent;

	struct cgroup *tmp_cg;

	struct cpuset *parent, *cs;

	struct cpuset *cs;



	if (!parent_cg)

	if (!cont->parent)

		return &top_cpuset.css;

	parent = cgroup_cs(parent_cg);



	cs = kmalloc(sizeof(*cs), GFP_KERNEL);

	cs = kzalloc(sizeof(*cs), GFP_KERNEL);

	if (!cs)

		return ERR_PTR(-ENOMEM);

	if (!alloc_cpumask_var(&cs->cpus_allowed, GFP_KERNEL)) {
@@ -1806,22 +1803,34 @@ static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cont) 
		return ERR_PTR(-ENOMEM);

	}



	cs->flags = 0;

	if (is_spread_page(parent))

		set_bit(CS_SPREAD_PAGE, &cs->flags);

	if (is_spread_slab(parent))

		set_bit(CS_SPREAD_SLAB, &cs->flags);

	set_bit(CS_SCHED_LOAD_BALANCE, &cs->flags);

	cpumask_clear(cs->cpus_allowed);

	nodes_clear(cs->mems_allowed);

	fmeter_init(&cs->fmeter);

	cs->relax_domain_level = -1;

	cs->parent = cgroup_cs(cont->parent);



	return &cs->css;

}



static int cpuset_css_online(struct cgroup *cgrp)

{

	struct cpuset *cs = cgroup_cs(cgrp);

	struct cpuset *parent = cs->parent;

	struct cgroup *tmp_cg;



	if (!parent)

		return 0;



	if (is_spread_page(parent))

		set_bit(CS_SPREAD_PAGE, &cs->flags);

	if (is_spread_slab(parent))

		set_bit(CS_SPREAD_SLAB, &cs->flags);



	cs->parent = parent;

	number_of_cpusets++;



	if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &cont->flags))

		goto skip_clone;

	if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags))

		return 0;



	/*

	 * Clone @parent's configuration if CGRP_CPUSET_CLONE_CHILDREN is
@@ -1836,19 +1845,34 @@ static struct cgroup_subsys_state *cpuset_css_alloc(struct cgroup *cont) 
	 * changed to grant parent->cpus_allowed-sibling_cpus_exclusive

	 * (and likewise for mems) to the new cgroup.

	 */

	list_for_each_entry(tmp_cg, &parent_cg->children, sibling) {

	list_for_each_entry(tmp_cg, &cgrp->parent->children, sibling) {

		struct cpuset *tmp_cs = cgroup_cs(tmp_cg);



		if (is_mem_exclusive(tmp_cs) || is_cpu_exclusive(tmp_cs))

			goto skip_clone;

			return 0;

	}



	mutex_lock(&callback_mutex);

	cs->mems_allowed = parent->mems_allowed;

	cpumask_copy(cs->cpus_allowed, parent->cpus_allowed);

	mutex_unlock(&callback_mutex);

skip_clone:

	return &cs->css;



	return 0;

}



static void cpuset_css_offline(struct cgroup *cgrp)

{

	struct cpuset *cs = cgroup_cs(cgrp);



	/* css_offline is called w/o cgroup_mutex, grab it */

	cgroup_lock();



	if (is_sched_load_balance(cs))

		update_flag(CS_SCHED_LOAD_BALANCE, cs, 0);



	number_of_cpusets--;



	cgroup_unlock();

}



/*
@@ -1861,10 +1885,6 @@ static void cpuset_css_free(struct cgroup *cont) 
{

	struct cpuset *cs = cgroup_cs(cont);



	if (is_sched_load_balance(cs))

		update_flag(CS_SCHED_LOAD_BALANCE, cs, 0);



	number_of_cpusets--;

	free_cpumask_var(cs->cpus_allowed);

	kfree(cs);

}
@@ -1872,6 +1892,8 @@ static void cpuset_css_free(struct cgroup *cont) 
struct cgroup_subsys cpuset_subsys = {

	.name = "cpuset",

	.css_alloc = cpuset_css_alloc,

	.css_online = cpuset_css_online,

	.css_offline = cpuset_css_offline,

	.css_free = cpuset_css_free,

	.can_attach = cpuset_can_attach,

	.attach = cpuset_attach,

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