mm/dynamic_hugetlb: free pages to dhugetlb_pool

hulk inclusion
category: feature
bugzilla: 46904, https://gitee.com/openeuler/kernel/issues/I4QSHG
CVE: NA

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

Add function to free page to dhugetlb_pool.
Signed-off-by: NLiu Shixin <liushixin2@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

include/linux/dynamic_hugetlb.h

@@ -90,6 +90,8 @@ void __init dynamic_hugetlb_init(void);
 
 struct page *alloc_page_from_dhugetlb_pool(gfp_t gfp, unsigned int order,
 					   unsigned int flags);
+bool free_page_to_dhugetlb_pool(struct page *page);
+void free_page_list_to_dhugetlb_pool(struct list_head *list);
 int task_has_mem_in_hpool(struct task_struct *tsk);
 
 #else
@@ -118,6 +120,13 @@ static inline struct page *alloc_page_from_dhugetlb_pool(gfp_t gfp, unsigned int
 {
 	return NULL;
 }
+static inline bool free_page_to_dhugetlb_pool(struct page *page)
+{
+	return false;
+}
+static inline void free_page_list_to_dhugetlb_pool(struct list_head *list)
+{
+}
 static inline int task_has_mem_in_hpool(struct task_struct *tsk)
 {
 	return 0;

mm/dynamic_hugetlb.c

@@ -378,6 +378,18 @@ static int set_hpool_in_dhugetlb_pagelist(unsigned long idx, struct dhugetlb_poo
 	return 0;
 }
 
+static struct dhugetlb_pool *find_hpool_by_dhugetlb_pagelist(struct page *page)
+{
+	unsigned long idx = hugepage_index(page_to_pfn(page));
+	struct dhugetlb_pool *hpool = NULL;
+
+	read_lock(&dhugetlb_pagelist_rwlock);
+	if (idx < dhugetlb_pagelist_t->count)
+		hpool = dhugetlb_pagelist_t->hpool[idx];
+	read_unlock(&dhugetlb_pagelist_rwlock);
+	return hpool;
+}
+
 static struct dhugetlb_pool *find_hpool_by_task(struct task_struct *tsk)
 {
 	struct mem_cgroup *memcg;
@@ -485,6 +497,62 @@ struct page *alloc_page_from_dhugetlb_pool(gfp_t gfp, unsigned int order,
 	return page;
 }
 
+static void __free_page_to_dhugetlb_pool(struct page *page)
+{
+	struct percpu_pages_pool *percpu_pool;
+	struct dhugetlb_pool *hpool;
+	unsigned long flags;
+
+	hpool = find_hpool_by_dhugetlb_pagelist(page);
+
+	if (!get_hpool_unless_zero(hpool)) {
+		pr_err("dhugetlb: free error: get hpool failed\n");
+		return;
+	}
+
+	percpu_pool = &hpool->percpu_pool[smp_processor_id()];
+	spin_lock_irqsave(&percpu_pool->lock, flags);
+
+	ClearPagePool(page);
+	list_add(&page->lru, &percpu_pool->head_page);
+	percpu_pool->free_pages++;
+	percpu_pool->used_pages--;
+	if (percpu_pool->free_pages > PERCPU_POOL_PAGE_MAX) {
+		spin_lock(&hpool->lock);
+		reclaim_pages_from_percpu_pool(hpool, percpu_pool, PERCPU_POOL_PAGE_BATCH);
+		spin_unlock(&hpool->lock);
+	}
+
+	spin_unlock_irqrestore(&percpu_pool->lock, flags);
+	put_hpool(hpool);
+}
+
+bool free_page_to_dhugetlb_pool(struct page *page)
+{
+	if (!dhugetlb_enabled || !PagePool(page))
+		return false;
+
+	if (free_pages_prepare(page, 0, true))
+		__free_page_to_dhugetlb_pool(page);
+	return true;
+}
+
+void free_page_list_to_dhugetlb_pool(struct list_head *list)
+{
+	struct page *page, *next;
+
+	if (!dhugetlb_enabled)
+		return;
+
+	list_for_each_entry_safe(page, next, list, lru) {
+		if (PagePool(page)) {
+			list_del(&page->lru);
+			if (free_pages_prepare(page, 0, true))
+				__free_page_to_dhugetlb_pool(page);
+		}
+	}
+}
+
 static int alloc_hugepage_from_hugetlb(struct dhugetlb_pool *hpool,
 				       unsigned long nid, unsigned long nr_pages)
 {

mm/page_alloc.c

@@ -3230,6 +3230,10 @@ void free_unref_page(struct page *page)
 	unsigned long flags;
 	unsigned long pfn = page_to_pfn(page);
 
+	/* Free dynamic hugetlb page */
+	if (free_page_to_dhugetlb_pool(page))
+		return;
+
 	if (!free_unref_page_prepare(page, pfn))
 		return;
 
@@ -3247,6 +3251,9 @@ void free_unref_page_list(struct list_head *list)
 	unsigned long flags, pfn;
 	int batch_count = 0;
 
+	/* Free dynamic hugetlb page list */
+	free_page_list_to_dhugetlb_pool(list);
+
 	/* Prepare pages for freeing */
 	list_for_each_entry_safe(page, next, list, lru) {
 		pfn = page_to_pfn(page);