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1// SPDX-License-Identifier: GPL-2.0+2/*3 * test_free_pages.c: Check that free_pages() doesn't leak memory4 * Copyright (c) 2020 Oracle5 * Author: Matthew Wilcox <willy@infradead.org>6 */7 8#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt9 10#include <linux/gfp.h>11#include <linux/mm.h>12#include <linux/module.h>13 14static void test_free_pages(gfp_t gfp)15{16 unsigned int i;17 18 for (i = 0; i < 1000 * 1000; i++) {19 unsigned long addr = __get_free_pages(gfp, 3);20 struct page *page = virt_to_page((void *)addr);21 22 /* Simulate page cache getting a speculative reference */23 get_page(page);24 free_pages(addr, 3);25 put_page(page);26 }27}28 29static int m_in(void)30{31 pr_info("Testing with GFP_KERNEL\n");32 test_free_pages(GFP_KERNEL);33 pr_info("Testing with GFP_KERNEL | __GFP_COMP\n");34 test_free_pages(GFP_KERNEL | __GFP_COMP);35 pr_info("Test completed\n");36 37 return 0;38}39 40static void m_ex(void)41{42}43 44module_init(m_in);45module_exit(m_ex);46MODULE_AUTHOR("Matthew Wilcox <willy@infradead.org>");47MODULE_DESCRIPTION("Check that free_pages() doesn't leak memory");48MODULE_LICENSE("GPL");49