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/* 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 <sjpark@amazon.de>
*/
#ifdef CONFIG_DAMON_VADDR_KUNIT_TEST
#ifndef _DAMON_VADDR_TEST_H
#define _DAMON_VADDR_TEST_H
#include <kunit/test.h>
static void __link_vmas(struct vm_area_struct *vmas, ssize_t nr_vmas)
{
int i, j;
unsigned long largest_gap, gap;
if (!nr_vmas)
return;
for (i = 0; i < nr_vmas - 1; i++) {
vmas[i].vm_next = &vmas[i + 1];
vmas[i].vm_rb.rb_left = NULL;
vmas[i].vm_rb.rb_right = &vmas[i + 1].vm_rb;
largest_gap = 0;
for (j = i; j < nr_vmas; j++) {
if (j == 0)
continue;
gap = vmas[j].vm_start - vmas[j - 1].vm_end;
if (gap > largest_gap)
largest_gap = gap;
}
vmas[i].rb_subtree_gap = largest_gap;
}
vmas[i].vm_next = NULL;
vmas[i].vm_rb.rb_right = NULL;
vmas[i].rb_subtree_gap = 0;
}
/*
* 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)
{
struct damon_addr_range regions[3] = {0,};
/* 10-20-25, 200-210-220, 300-305, 307-330 */
struct vm_area_struct vmas[] = {
(struct vm_area_struct) {.vm_start = 10, .vm_end = 20},
(struct vm_area_struct) {.vm_start = 20, .vm_end = 25},
(struct vm_area_struct) {.vm_start = 200, .vm_end = 210},
(struct vm_area_struct) {.vm_start = 210, .vm_end = 220},
(struct vm_area_struct) {.vm_start = 300, .vm_end = 305},
(struct vm_area_struct) {.vm_start = 307, .vm_end = 330},
};
__link_vmas(vmas, 6);
__damon_va_three_regions(&vmas[0], regions);
KUNIT_EXPECT_EQ(test, 10ul, regions[0].start);
KUNIT_EXPECT_EQ(test, 25ul, regions[0].end);
KUNIT_EXPECT_EQ(test, 200ul, regions[1].start);
KUNIT_EXPECT_EQ(test, 220ul, regions[1].end);
KUNIT_EXPECT_EQ(test, 300ul, regions[2].start);
KUNIT_EXPECT_EQ(test, 330ul, regions[2].end);
}
static struct damon_region *__nth_region_of(struct damon_target *t, int idx)
{
struct damon_region *r;
unsigned int i = 0;
damon_for_each_region(r, t) {
if (i++ == idx)
return r;
}
return NULL;
}
/*
* Test 'damon_va_apply_three_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_va_apply_three_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)
{
struct damon_target *t;
struct damon_region *r;
int i;
t = damon_new_target(42);
for (i = 0; i < nr_regions / 2; i++) {
r = damon_new_region(regions[i * 2], regions[i * 2 + 1]);
damon_add_region(r, t);
}
damon_va_apply_three_regions(t, three_regions);
for (i = 0; i < nr_expected / 2; i++) {
r = __nth_region_of(t, i);
KUNIT_EXPECT_EQ(test, r->ar.start, expected[i * 2]);
KUNIT_EXPECT_EQ(test, r->ar.end, expected[i * 2 + 1]);
}
}
/*
* 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)
{
/* 10-20-30, 50-55-57-59, 70-80-90-100 */
unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
70, 80, 80, 90, 90, 100};
/* 5-27, 45-55, 73-104 */
struct damon_addr_range new_three_regions[3] = {
(struct damon_addr_range){.start = 5, .end = 27},
(struct damon_addr_range){.start = 45, .end = 55},
(struct damon_addr_range){.start = 73, .end = 104} };
/* 5-20-27, 45-55, 73-80-90-104 */
unsigned long expected[] = {5, 20, 20, 27, 45, 55,
73, 80, 80, 90, 90, 104};
damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
new_three_regions, expected, ARRAY_SIZE(expected));
}
/*
* 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)
{
/* 10-20-30, 50-55-57-59, 70-80-90-100 */
unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
70, 80, 80, 90, 90, 100};
/* 5-27, 56-57, 65-104 */
struct damon_addr_range new_three_regions[3] = {
(struct damon_addr_range){.start = 5, .end = 27},
(struct damon_addr_range){.start = 56, .end = 57},
(struct damon_addr_range){.start = 65, .end = 104} };
/* 5-20-27, 56-57, 65-80-90-104 */
unsigned long expected[] = {5, 20, 20, 27, 56, 57,
65, 80, 80, 90, 90, 104};
damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
new_three_regions, expected, ARRAY_SIZE(expected));
}
/*
* 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)
{
/* 10-20-30, 50-55-57-59, 70-80-90-100 */
unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
70, 80, 80, 90, 90, 100};
/* 5-27, 61-63, 65-104 */
struct damon_addr_range new_three_regions[3] = {
(struct damon_addr_range){.start = 5, .end = 27},
(struct damon_addr_range){.start = 61, .end = 63},
(struct damon_addr_range){.start = 65, .end = 104} };
/* 5-20-27, 61-63, 65-80-90-104 */
unsigned long expected[] = {5, 20, 20, 27, 61, 63,
65, 80, 80, 90, 90, 104};
damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
new_three_regions, expected, ARRAY_SIZE(expected));
}
/*
* 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)
{
/* 10-20-30, 50-55-57-59, 70-80-90-100 */
unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
70, 80, 80, 90, 90, 100};
/* 5-7, 30-32, 65-68 */
struct damon_addr_range new_three_regions[3] = {
(struct damon_addr_range){.start = 5, .end = 7},
(struct damon_addr_range){.start = 30, .end = 32},
(struct damon_addr_range){.start = 65, .end = 68} };
/* expect 5-7, 30-32, 65-68 */
unsigned long expected[] = {5, 7, 30, 32, 65, 68};
damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
new_three_regions, expected, ARRAY_SIZE(expected));
}
static void damon_test_split_evenly_fail(struct kunit *test,
unsigned long start, unsigned long end, unsigned int nr_pieces)
{
struct damon_target *t = damon_new_target(42);
struct damon_region *r = damon_new_region(start, end);
damon_add_region(r, t);
KUNIT_EXPECT_EQ(test,
damon_va_evenly_split_region(t, r, nr_pieces), -EINVAL);
KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 1u);
damon_for_each_region(r, t) {
KUNIT_EXPECT_EQ(test, r->ar.start, start);
KUNIT_EXPECT_EQ(test, r->ar.end, end);
}
damon_free_target(t);
}
static void damon_test_split_evenly_succ(struct kunit *test,
unsigned long start, unsigned long end, unsigned int nr_pieces)
{
struct damon_target *t = damon_new_target(42);
struct damon_region *r = damon_new_region(start, end);
unsigned long expected_width = (end - start) / nr_pieces;
unsigned long i = 0;
damon_add_region(r, t);
KUNIT_EXPECT_EQ(test,
damon_va_evenly_split_region(t, r, nr_pieces), 0);
KUNIT_EXPECT_EQ(test, damon_nr_regions(t), nr_pieces);
damon_for_each_region(r, t) {
if (i == nr_pieces - 1)
break;
KUNIT_EXPECT_EQ(test,
r->ar.start, start + i++ * expected_width);
KUNIT_EXPECT_EQ(test, r->ar.end, start + i * expected_width);
}
KUNIT_EXPECT_EQ(test, r->ar.start, start + i * expected_width);
KUNIT_EXPECT_EQ(test, r->ar.end, end);
damon_free_target(t);
}
static void damon_test_split_evenly(struct kunit *test)
{
KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(NULL, NULL, 5),
-EINVAL);
damon_test_split_evenly_fail(test, 0, 100, 0);
damon_test_split_evenly_succ(test, 0, 100, 10);
damon_test_split_evenly_succ(test, 5, 59, 5);
damon_test_split_evenly_fail(test, 5, 6, 2);
}
static struct kunit_case damon_test_cases[] = {
KUNIT_CASE(damon_test_three_regions_in_vmas),
KUNIT_CASE(damon_test_apply_three_regions1),
KUNIT_CASE(damon_test_apply_three_regions2),
KUNIT_CASE(damon_test_apply_three_regions3),
KUNIT_CASE(damon_test_apply_three_regions4),
KUNIT_CASE(damon_test_split_evenly),
{},
};
static struct kunit_suite damon_test_suite = {
.name = "damon-primitives",
.test_cases = damon_test_cases,
};
kunit_test_suite(damon_test_suite);
#endif /* _DAMON_VADDR_TEST_H */
#endif /* CONFIG_DAMON_VADDR_KUNIT_TEST */