Commit 4e5c0aff authored by Liu Shixin's avatar Liu Shixin
Browse files

mm/dynamic_pool: add restore_pool ops to reclaim memory and restore hugepages 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8S9BY


CVE: NA

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

Before destroy a dynamic pool, make sure all memory are freed and all
split hugepages are restored.

Signed-off-by: default avatarLiu Shixin <liushixin2@huawei.com>
parent 6f1e0f63

include/linux/dynamic_pool.h

+9 −0
Original line number Diff line number Diff line
@@ -18,6 +18,11 @@ enum pages_pool_type { 
	PAGES_POOL_MAX,

};



struct split_page {

	struct list_head entry;

	unsigned long start_pfn;

};



struct pages_pool {

	unsigned long free_pages;

	unsigned long used_pages;
@@ -28,6 +33,10 @@ struct pages_pool { 
	unsigned long free_huge_pages;

	unsigned long resv_huge_pages;

	unsigned long used_huge_pages;



	/* Used for split page */

	unsigned long split_pages;

	struct list_head splitlist;

};



struct dynamic_pool_ops;

mm/dynamic_pool.c

+54 −1
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ static DEFINE_MUTEX(dpool_mutex); 
struct dynamic_pool_ops {

	int (*fill_pool)(struct dynamic_pool *dpool, void *arg);

	int (*drain_pool)(struct dynamic_pool *dpool);

	int (*restore_pool)(struct dynamic_pool *dpool);

};



/* Used to record the mapping of page and dpool */
@@ -108,8 +109,10 @@ static struct dynamic_pool *dpool_create(struct mem_cgroup *memcg, 
	dpool->memcg = memcg;

	dpool->ops = ops;



	for (i = 0; i < PAGES_POOL_MAX; i++)

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

		INIT_LIST_HEAD(&dpool->pool[i].freelist);

		INIT_LIST_HEAD(&dpool->pool[i].splitlist);

	}



	css_get(&memcg->css);

	memcg->dpool = dpool;
@@ -158,6 +161,13 @@ int dynamic_pool_destroy(struct cgroup *cgrp, bool *clear_css_online) 
	/* A offline dpool is not allowed for allocation */

	dpool->online = false;



	BUG_ON(!dpool->ops->restore_pool);

	ret = dpool->ops->restore_pool(dpool);

	if (ret) {

		pr_err("restore pool failed\n");

		goto put;

	}



	BUG_ON(!dpool->ops->drain_pool);

	ret = dpool->ops->drain_pool(dpool);

	if (ret) {
@@ -345,9 +355,52 @@ static int dpool_drain_to_hugetlb(struct dynamic_pool *dpool) 
	return dpool->total_pages ? -ENOMEM : 0;

}



static int dpool_merge_all(struct dynamic_pool *dpool)

{

	struct pages_pool *pool;

	int ret = -ENOMEM;



	pool = &dpool->pool[PAGES_POOL_2M];

	spin_lock(&dpool->lock);

	if (pool->split_pages || pool->used_huge_pages || pool->resv_huge_pages) {

		ret = -ENOMEM;

		pr_err("some 2M pages are still in use or mmap, delete failed: ");

		pr_cont_cgroup_name(dpool->memcg->css.cgroup);

		pr_cont("\n");

		spin_unlock(&dpool->lock);

		goto out;

	}



	pool->free_pages += pool->nr_huge_pages;

	pool->nr_huge_pages = 0;

	pool->free_huge_pages = 0;

	spin_unlock(&dpool->lock);



	pool = &dpool->pool[PAGES_POOL_1G];

	spin_lock(&dpool->lock);

	if (pool->split_pages || pool->used_huge_pages || pool->resv_huge_pages) {

		ret = -ENOMEM;

		pr_err("some 1G pages are still in use or mmap, delete failed: ");

		pr_cont_cgroup_name(dpool->memcg->css.cgroup);

		pr_cont("\n");

		spin_unlock(&dpool->lock);

		goto out;

	}



	pool->free_pages += pool->nr_huge_pages;

	pool->nr_huge_pages = 0;

	pool->free_huge_pages = 0;

	spin_unlock(&dpool->lock);

	ret = 0;



out:

	return ret;

}



static struct dynamic_pool_ops hugetlb_dpool_ops = {

	.fill_pool = dpool_fill_from_hugetlb,

	.drain_pool = dpool_drain_to_hugetlb,

	.restore_pool = dpool_merge_all,

};



/* If dynamic pool is disabled, hide the interface */