Commit 7a4d01c1 authored by Gaosheng Cui's avatar Gaosheng Cui
Browse files

Revert "cgroup: Stop task iteration when rebinding subsystem" 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7AZ85



--------------------------------

This reverts commit e52586f4.

Signed-off-by: default avatarGaosheng Cui <cuigaosheng1@huawei.com>
parent 0a7be323

include/linux/cgroup.h

+0 −1
Original line number Diff line number Diff line
@@ -47,7 +47,6 @@ struct kernel_clone_args; 


/* internal flags */

#define CSS_TASK_ITER_SKIPPED		(1U << 16)

#define CSS_TASK_ITER_STOPPED		(1U << 17)



/* a css_task_iter should be treated as an opaque object */

struct css_task_iter {

kernel/cgroup/cgroup.c

+1 −33
Original line number Diff line number Diff line
@@ -215,8 +215,6 @@ static int cgroup_apply_control(struct cgroup *cgrp); 
static void cgroup_finalize_control(struct cgroup *cgrp, int ret);

static void css_task_iter_skip(struct css_task_iter *it,

			       struct task_struct *task);

static void css_task_iter_stop(struct css_task_iter *it,

			       struct cgroup_subsys *ss);

static int cgroup_destroy_locked(struct cgroup *cgrp);

static struct cgroup_subsys_state *css_create(struct cgroup *cgrp,

					      struct cgroup_subsys *ss);
@@ -857,19 +855,6 @@ static void css_set_skip_task_iters(struct css_set *cset, 
		css_task_iter_skip(it, task);

}



/*

 * @cset is moving to other list, it's not safe to continue the iteration,

 * because the cset_head of css_task_iter which is from the old list can

 * not be used as the stop condition of iteration.

 */

static void css_set_stop_iters(struct css_set *cset, struct cgroup_subsys *ss)

{

	struct css_task_iter *it, *pos;



	list_for_each_entry_safe(it, pos, &cset->task_iters, iters_node)

		css_task_iter_stop(it, ss);

}



/**

 * css_set_move_task - move a task from one css_set to another

 * @task: task being moved
@@ -1790,11 +1775,9 @@ int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask) 
		css->cgroup = dcgrp;



		spin_lock_irq(&css_set_lock);

		hash_for_each(css_set_table, i, cset, hlist) {

			css_set_stop_iters(cset, ss);

		hash_for_each(css_set_table, i, cset, hlist)

			list_move_tail(&cset->e_cset_node[ss->id],

				       &dcgrp->e_csets[ss->id]);

		}

		spin_unlock_irq(&css_set_lock);



		if (ss->css_rstat_flush) {
@@ -4723,16 +4706,6 @@ static void css_task_iter_skip(struct css_task_iter *it, 
	}

}



static void css_task_iter_stop(struct css_task_iter *it,

			       struct cgroup_subsys *ss)

{

	lockdep_assert_held(&css_set_lock);



	if (it->ss == ss) {

		it->flags |= CSS_TASK_ITER_STOPPED;

	}

}



static void css_task_iter_advance(struct css_task_iter *it)

{

	struct task_struct *task;
@@ -4836,11 +4809,6 @@ struct task_struct *css_task_iter_next(struct css_task_iter *it) 


	spin_lock_irq(&css_set_lock);



	if (it->flags & CSS_TASK_ITER_STOPPED) {

		spin_unlock_irq(&css_set_lock);

		return NULL;

	}



	/* @it may be half-advanced by skips, finish advancing */

	if (it->flags & CSS_TASK_ITER_SKIPPED)

		css_task_iter_advance(it);