Commit 56805c1b authored by Chen Ridong's avatar Chen Ridong Committed by Tejun Heo
Browse files

cpuset: add cpuset1_online_css helper for v1-specific operations 



This commit introduces the cpuset1_online_css helper to centralize
v1-specific handling during cpuset online. It performs operations such as
updating the CS_SPREAD_PAGE, CS_SPREAD_SLAB, and CGRP_CPUSET_CLONE_CHILDREN
flags, which are unique to the cpuset v1 control group interface.

The helper is now placed in cpuset-v1.c to maintain clear separation
between v1 and v2 logic.

Signed-off-by: default avatarChen Ridong <chenridong@huawei.com>
Reviewed-by: default avatarWaiman Long <longman@redhat.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 14c11e1b

kernel/cgroup/cpuset-internal.h

+2 −0
Original line number Diff line number Diff line
@@ -293,6 +293,7 @@ void cpuset1_hotplug_update_tasks(struct cpuset *cs, 
			    struct cpumask *new_cpus, nodemask_t *new_mems,

			    bool cpus_updated, bool mems_updated);

int cpuset1_validate_change(struct cpuset *cur, struct cpuset *trial);

void cpuset1_online_css(struct cgroup_subsys_state *css);

#else

static inline void fmeter_init(struct fmeter *fmp) {}

static inline void cpuset1_update_task_spread_flags(struct cpuset *cs,
@@ -303,6 +304,7 @@ static inline void cpuset1_hotplug_update_tasks(struct cpuset *cs, 
			    bool cpus_updated, bool mems_updated) {}

static inline int cpuset1_validate_change(struct cpuset *cur,

				struct cpuset *trial) { return 0; }

static inline void cpuset1_online_css(struct cgroup_subsys_state *css) {}

#endif /* CONFIG_CPUSETS_V1 */



#endif /* __CPUSET_INTERNAL_H */

kernel/cgroup/cpuset-v1.c

+48 −0
Original line number Diff line number Diff line
@@ -499,6 +499,54 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft, 
	return retval;

}



void cpuset1_online_css(struct cgroup_subsys_state *css)

{

	struct cpuset *tmp_cs;

	struct cgroup_subsys_state *pos_css;

	struct cpuset *cs = css_cs(css);

	struct cpuset *parent = parent_cs(cs);



	lockdep_assert_cpus_held();

	lockdep_assert_cpuset_lock_held();



	if (is_spread_page(parent))

		set_bit(CS_SPREAD_PAGE, &cs->flags);

	if (is_spread_slab(parent))

		set_bit(CS_SPREAD_SLAB, &cs->flags);



	if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags))

		return;



	/*

	 * Clone @parent's configuration if CGRP_CPUSET_CLONE_CHILDREN is

	 * set.  This flag handling is implemented in cgroup core for

	 * historical reasons - the flag may be specified during mount.

	 *

	 * Currently, if any sibling cpusets have exclusive cpus or mem, we

	 * refuse to clone the configuration - thereby refusing the task to

	 * be entered, and as a result refusing the sys_unshare() or

	 * clone() which initiated it.  If this becomes a problem for some

	 * users who wish to allow that scenario, then this could be

	 * changed to grant parent->cpus_allowed-sibling_cpus_exclusive

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

	 */

	rcu_read_lock();

	cpuset_for_each_child(tmp_cs, pos_css, parent) {

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

			rcu_read_unlock();

			return;

		}

	}

	rcu_read_unlock();



	cpuset_callback_lock_irq();

	cs->mems_allowed = parent->mems_allowed;

	cs->effective_mems = parent->mems_allowed;

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

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

	cpuset_callback_unlock_irq();

}



/*

 * for the common functions, 'private' gives the type of file

 */

kernel/cgroup/cpuset.c

+1 −38
Original line number Diff line number Diff line
@@ -3616,17 +3616,11 @@ static int cpuset_css_online(struct cgroup_subsys_state *css) 
{

	struct cpuset *cs = css_cs(css);

	struct cpuset *parent = parent_cs(cs);

	struct cpuset *tmp_cs;

	struct cgroup_subsys_state *pos_css;



	if (!parent)

		return 0;



	cpuset_full_lock();

	if (is_spread_page(parent))

		set_bit(CS_SPREAD_PAGE, &cs->flags);

	if (is_spread_slab(parent))

		set_bit(CS_SPREAD_SLAB, &cs->flags);

	/*

	 * For v2, clear CS_SCHED_LOAD_BALANCE if parent is isolated

	 */
@@ -3641,39 +3635,8 @@ static int cpuset_css_online(struct cgroup_subsys_state *css) 
		cs->effective_mems = parent->effective_mems;

	}

	spin_unlock_irq(&callback_lock);

	cpuset1_online_css(css);



	if (!test_bit(CGRP_CPUSET_CLONE_CHILDREN, &css->cgroup->flags))

		goto out_unlock;



	/*

	 * Clone @parent's configuration if CGRP_CPUSET_CLONE_CHILDREN is

	 * set.  This flag handling is implemented in cgroup core for

	 * historical reasons - the flag may be specified during mount.

	 *

	 * Currently, if any sibling cpusets have exclusive cpus or mem, we

	 * refuse to clone the configuration - thereby refusing the task to

	 * be entered, and as a result refusing the sys_unshare() or

	 * clone() which initiated it.  If this becomes a problem for some

	 * users who wish to allow that scenario, then this could be

	 * changed to grant parent->cpus_allowed-sibling_cpus_exclusive

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

	 */

	rcu_read_lock();

	cpuset_for_each_child(tmp_cs, pos_css, parent) {

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

			rcu_read_unlock();

			goto out_unlock;

		}

	}

	rcu_read_unlock();



	spin_lock_irq(&callback_lock);

	cs->mems_allowed = parent->mems_allowed;

	cs->effective_mems = parent->mems_allowed;

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

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

	spin_unlock_irq(&callback_lock);

out_unlock:

	cpuset_full_unlock();

	return 0;

}