vaddr-test.h | Explore in Territory

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Data Access Monitor Unit Tests
 *
 * Copyright 2019 Amazon.com, Inc. or its affiliates.  All rights reserved.
 *
 * Author: SeongJae Park <[email protected]>
 */

#ifdef CONFIG_DAMON_VADDR_KUNIT_TEST

#ifndef _DAMON_VADDR_TEST_H
#define _DAMON_VADDR_TEST_H

#include <kunit/test.h>

static int __link_vmas(struct maple_tree *mt, struct vm_area_struct *vmas,
			ssize_t nr_vmas)
{ … }

/*
 * Test __damon_va_three_regions() function
 *
 * In case of virtual memory address spaces monitoring, DAMON converts the
 * complex and dynamic memory mappings of each target task to three
 * discontiguous regions which cover every mapped areas.  However, the three
 * regions should not include the two biggest unmapped areas in the original
 * mapping, because the two biggest areas are normally the areas between 1)
 * heap and the mmap()-ed regions, and 2) the mmap()-ed regions and stack.
 * Because these two unmapped areas are very huge but obviously never accessed,
 * covering the region is just a waste.
 *
 * '__damon_va_three_regions() receives an address space of a process.  It
 * first identifies the start of mappings, end of mappings, and the two biggest
 * unmapped areas.  After that, based on the information, it constructs the
 * three regions and returns.  For more detail, refer to the comment of
 * 'damon_init_regions_of()' function definition in 'mm/damon.c' file.
 *
 * For example, suppose virtual address ranges of 10-20, 20-25, 200-210,
 * 210-220, 300-305, and 307-330 (Other comments represent this mappings in
 * more short form: 10-20-25, 200-210-220, 300-305, 307-330) of a process are
 * mapped.  To cover every mappings, the three regions should start with 10,
 * and end with 305.  The process also has three unmapped areas, 25-200,
 * 220-300, and 305-307.  Among those, 25-200 and 220-300 are the biggest two
 * unmapped areas, and thus it should be converted to three regions of 10-25,
 * 200-220, and 300-330.
 */
static void damon_test_three_regions_in_vmas(struct kunit *test)
{ … }

static struct damon_region *__nth_region_of(struct damon_target *t, int idx)
{ … }

/*
 * Test 'damon_set_regions()'
 *
 * test			kunit object
 * regions		an array containing start/end addresses of current
 *			monitoring target regions
 * nr_regions		the number of the addresses in 'regions'
 * three_regions	The three regions that need to be applied now
 * expected		start/end addresses of monitoring target regions that
 *			'three_regions' are applied
 * nr_expected		the number of addresses in 'expected'
 *
 * The memory mapping of the target processes changes dynamically.  To follow
 * the change, DAMON periodically reads the mappings, simplifies it to the
 * three regions, and updates the monitoring target regions to fit in the three
 * regions.  The update of current target regions is the role of
 * 'damon_set_regions()'.
 *
 * This test passes the given target regions and the new three regions that
 * need to be applied to the function and check whether it updates the regions
 * as expected.
 */
static void damon_do_test_apply_three_regions(struct kunit *test,
				unsigned long *regions, int nr_regions,
				struct damon_addr_range *three_regions,
				unsigned long *expected, int nr_expected)
{ … }

/*
 * This function test most common case where the three big regions are only
 * slightly changed.  Target regions should adjust their boundary (10-20-30,
 * 50-55, 70-80, 90-100) to fit with the new big regions or remove target
 * regions (57-79) that now out of the three regions.
 */
static void damon_test_apply_three_regions1(struct kunit *test)
{ … }

/*
 * Test slightly bigger change.  Similar to above, but the second big region
 * now require two target regions (50-55, 57-59) to be removed.
 */
static void damon_test_apply_three_regions2(struct kunit *test)
{ … }

/*
 * Test a big change.  The second big region has totally freed and mapped to
 * different area (50-59 -> 61-63).  The target regions which were in the old
 * second big region (50-55-57-59) should be removed and new target region
 * covering the second big region (61-63) should be created.
 */
static void damon_test_apply_three_regions3(struct kunit *test)
{ … }

/*
 * Test another big change.  Both of the second and third big regions (50-59
 * and 70-100) has totally freed and mapped to different area (30-32 and
 * 65-68).  The target regions which were in the old second and third big
 * regions should now be removed and new target regions covering the new second
 * and third big regions should be created.
 */
static void damon_test_apply_three_regions4(struct kunit *test)
{ … }

static void damon_test_split_evenly_fail(struct kunit *test,
		unsigned long start, unsigned long end, unsigned int nr_pieces)
{ … }

static void damon_test_split_evenly_succ(struct kunit *test,
	unsigned long start, unsigned long end, unsigned int nr_pieces)
{ … }

static void damon_test_split_evenly(struct kunit *test)
{ … }

static struct kunit_case damon_test_cases[] = …;

static struct kunit_suite damon_test_suite = …;
kunit_test_suite(…) …;

#endif /* _DAMON_VADDR_TEST_H */

#endif	/* CONFIG_DAMON_VADDR_KUNIT_TEST */
linux/mm/damon/vaddr-test.h
