1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Data Access Monitor Unit Tests
4 */
5
6 #ifdef CONFIG_DAMON_VADDR_KUNIT_TEST
7
8 #ifndef _DAMON_VADDR_TEST_H
9 #define _DAMON_VADDR_TEST_H
10
11 #include <kunit/test.h>
12
__link_vmas(struct maple_tree * mt,struct vm_area_struct * vmas,ssize_t nr_vmas)13 static int __link_vmas(struct maple_tree *mt, struct vm_area_struct *vmas,
14 ssize_t nr_vmas)
15 {
16 int i, ret = -ENOMEM;
17 MA_STATE(mas, mt, 0, 0);
18
19 if (!nr_vmas)
20 return 0;
21
22 mas_lock(&mas);
23 for (i = 0; i < nr_vmas; i++) {
24 mas_set_range(&mas, vmas[i].vm_start, vmas[i].vm_end - 1);
25 if (mas_store_gfp(&mas, &vmas[i], GFP_KERNEL))
26 goto failed;
27 }
28
29 ret = 0;
30 failed:
31 mas_unlock(&mas);
32 return ret;
33 }
34
35 /*
36 * Test __damon_va_three_regions() function
37 *
38 * In case of virtual memory address spaces monitoring, DAMON converts the
39 * complex and dynamic memory mappings of each target task to three
40 * discontiguous regions which cover every mapped areas. However, the three
41 * regions should not include the two biggest unmapped areas in the original
42 * mapping, because the two biggest areas are normally the areas between 1)
43 * heap and the mmap()-ed regions, and 2) the mmap()-ed regions and stack.
44 * Because these two unmapped areas are very huge but obviously never accessed,
45 * covering the region is just a waste.
46 *
47 * '__damon_va_three_regions() receives an address space of a process. It
48 * first identifies the start of mappings, end of mappings, and the two biggest
49 * unmapped areas. After that, based on the information, it constructs the
50 * three regions and returns. For more detail, refer to the comment of
51 * 'damon_init_regions_of()' function definition in 'mm/damon.c' file.
52 *
53 * For example, suppose virtual address ranges of 10-20, 20-25, 200-210,
54 * 210-220, 300-305, and 307-330 (Other comments represent this mappings in
55 * more short form: 10-20-25, 200-210-220, 300-305, 307-330) of a process are
56 * mapped. To cover every mappings, the three regions should start with 10,
57 * and end with 305. The process also has three unmapped areas, 25-200,
58 * 220-300, and 305-307. Among those, 25-200 and 220-300 are the biggest two
59 * unmapped areas, and thus it should be converted to three regions of 10-25,
60 * 200-220, and 300-330.
61 */
damon_test_three_regions_in_vmas(struct kunit * test)62 static void damon_test_three_regions_in_vmas(struct kunit *test)
63 {
64 static struct mm_struct mm;
65 struct damon_addr_range regions[3] = {0};
66 /* 10-20-25, 200-210-220, 300-305, 307-330 */
67 static struct vm_area_struct vmas[] = {
68 (struct vm_area_struct) {.vm_start = 10, .vm_end = 20},
69 (struct vm_area_struct) {.vm_start = 20, .vm_end = 25},
70 (struct vm_area_struct) {.vm_start = 200, .vm_end = 210},
71 (struct vm_area_struct) {.vm_start = 210, .vm_end = 220},
72 (struct vm_area_struct) {.vm_start = 300, .vm_end = 305},
73 (struct vm_area_struct) {.vm_start = 307, .vm_end = 330},
74 };
75
76 mt_init_flags(&mm.mm_mt, MT_FLAGS_ALLOC_RANGE | MT_FLAGS_USE_RCU);
77 if (__link_vmas(&mm.mm_mt, vmas, ARRAY_SIZE(vmas)))
78 kunit_skip(test, "Failed to create VMA tree");
79
80 __damon_va_three_regions(&mm, regions);
81
82 KUNIT_EXPECT_EQ(test, 10ul, regions[0].start);
83 KUNIT_EXPECT_EQ(test, 25ul, regions[0].end);
84 KUNIT_EXPECT_EQ(test, 200ul, regions[1].start);
85 KUNIT_EXPECT_EQ(test, 220ul, regions[1].end);
86 KUNIT_EXPECT_EQ(test, 300ul, regions[2].start);
87 KUNIT_EXPECT_EQ(test, 330ul, regions[2].end);
88 }
89
__nth_region_of(struct damon_target * t,int idx)90 static struct damon_region *__nth_region_of(struct damon_target *t, int idx)
91 {
92 struct damon_region *r;
93 unsigned int i = 0;
94
95 damon_for_each_region(r, t) {
96 if (i++ == idx)
97 return r;
98 }
99
100 return NULL;
101 }
102
103 /*
104 * Test 'damon_set_regions()'
105 *
106 * test kunit object
107 * regions an array containing start/end addresses of current
108 * monitoring target regions
109 * nr_regions the number of the addresses in 'regions'
110 * three_regions The three regions that need to be applied now
111 * expected start/end addresses of monitoring target regions that
112 * 'three_regions' are applied
113 * nr_expected the number of addresses in 'expected'
114 *
115 * The memory mapping of the target processes changes dynamically. To follow
116 * the change, DAMON periodically reads the mappings, simplifies it to the
117 * three regions, and updates the monitoring target regions to fit in the three
118 * regions. The update of current target regions is the role of
119 * 'damon_set_regions()'.
120 *
121 * This test passes the given target regions and the new three regions that
122 * need to be applied to the function and check whether it updates the regions
123 * as expected.
124 */
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)125 static void damon_do_test_apply_three_regions(struct kunit *test,
126 unsigned long *regions, int nr_regions,
127 struct damon_addr_range *three_regions,
128 unsigned long *expected, int nr_expected)
129 {
130 struct damon_target *t;
131 struct damon_addr_range *ranges;
132 struct damon_region *r;
133 int i;
134
135 t = damon_new_target();
136 if (!t)
137 kunit_skip(test, "target alloc fail");
138
139 ranges = kmalloc_objs(*ranges, nr_regions / 2);
140 if (!ranges) {
141 damon_destroy_target(t, NULL);
142 kunit_skip(test, "ranges alloc fail");
143 }
144 for (i = 0; i < nr_regions / 2; i++) {
145 ranges[i].start = regions[i * 2];
146 ranges[i].end = regions[i * 2 + 1];
147 }
148 if (damon_set_regions(t, ranges, nr_regions / 2,
149 DAMON_MIN_REGION_SZ)) {
150 kfree(ranges);
151 damon_destroy_target(t, NULL);
152 kunit_skip(test, "damon_set_regions() fail");
153 }
154 kfree(ranges);
155
156 if (damon_set_regions(t, three_regions, 3, DAMON_MIN_REGION_SZ)) {
157 damon_destroy_target(t, NULL);
158 kunit_skip(test, "second damon_set_regions() fail");
159 }
160
161 KUNIT_EXPECT_EQ(test, damon_nr_regions(t), nr_expected / 2);
162 if (damon_nr_regions(t) != nr_expected / 2)
163 goto out;
164
165 for (i = 0; i < nr_expected / 2; i++) {
166 r = __nth_region_of(t, i);
167 KUNIT_EXPECT_EQ(test, r->ar.start, expected[i * 2]);
168 KUNIT_EXPECT_EQ(test, r->ar.end, expected[i * 2 + 1]);
169 }
170
171 out:
172 damon_destroy_target(t, NULL);
173 }
174
175 /*
176 * This function test most common case where the three big regions are only
177 * slightly changed. Target regions should adjust their boundary (10-20-30,
178 * 50-55, 70-80, 90-100) to fit with the new big regions or remove target
179 * regions (57-79) that now out of the three regions.
180 */
damon_test_apply_three_regions1(struct kunit * test)181 static void damon_test_apply_three_regions1(struct kunit *test)
182 {
183 /* 10-20-30, 50-55-57-59, 70-80-90-100 */
184 unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
185 70, 80, 80, 90, 90, 100};
186 /* 5-27, 45-55, 73-104 */
187 struct damon_addr_range new_three_regions[3] = {
188 (struct damon_addr_range){.start = 5, .end = 27},
189 (struct damon_addr_range){.start = 45, .end = 55},
190 (struct damon_addr_range){.start = 73, .end = 104} };
191 /* 5-20-27, 45-55, 73-80-90-104 */
192 unsigned long expected[] = {5, 20, 20, 27, 45, 55,
193 73, 80, 80, 90, 90, 104};
194
195 damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
196 new_three_regions, expected, ARRAY_SIZE(expected));
197 }
198
199 /*
200 * Test slightly bigger change. Similar to above, but the second big region
201 * now require two target regions (50-55, 57-59) to be removed.
202 */
damon_test_apply_three_regions2(struct kunit * test)203 static void damon_test_apply_three_regions2(struct kunit *test)
204 {
205 /* 10-20-30, 50-55-57-59, 70-80-90-100 */
206 unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
207 70, 80, 80, 90, 90, 100};
208 /* 5-27, 56-57, 65-104 */
209 struct damon_addr_range new_three_regions[3] = {
210 (struct damon_addr_range){.start = 5, .end = 27},
211 (struct damon_addr_range){.start = 56, .end = 57},
212 (struct damon_addr_range){.start = 65, .end = 104} };
213 /* 5-20-27, 56-57, 65-80-90-104 */
214 unsigned long expected[] = {5, 20, 20, 27, 56, 57,
215 65, 80, 80, 90, 90, 104};
216
217 damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
218 new_three_regions, expected, ARRAY_SIZE(expected));
219 }
220
221 /*
222 * Test a big change. The second big region has totally freed and mapped to
223 * different area (50-59 -> 61-63). The target regions which were in the old
224 * second big region (50-55-57-59) should be removed and new target region
225 * covering the second big region (61-63) should be created.
226 */
damon_test_apply_three_regions3(struct kunit * test)227 static void damon_test_apply_three_regions3(struct kunit *test)
228 {
229 /* 10-20-30, 50-55-57-59, 70-80-90-100 */
230 unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
231 70, 80, 80, 90, 90, 100};
232 /* 5-27, 61-63, 65-104 */
233 struct damon_addr_range new_three_regions[3] = {
234 (struct damon_addr_range){.start = 5, .end = 27},
235 (struct damon_addr_range){.start = 61, .end = 63},
236 (struct damon_addr_range){.start = 65, .end = 104} };
237 /* 5-20-27, 61-63, 65-80-90-104 */
238 unsigned long expected[] = {5, 20, 20, 27, 61, 63,
239 65, 80, 80, 90, 90, 104};
240
241 damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
242 new_three_regions, expected, ARRAY_SIZE(expected));
243 }
244
245 /*
246 * Test another big change. Both of the second and third big regions (50-59
247 * and 70-100) has totally freed and mapped to different area (30-32 and
248 * 65-68). The target regions which were in the old second and third big
249 * regions should now be removed and new target regions covering the new second
250 * and third big regions should be created.
251 */
damon_test_apply_three_regions4(struct kunit * test)252 static void damon_test_apply_three_regions4(struct kunit *test)
253 {
254 /* 10-20-30, 50-55-57-59, 70-80-90-100 */
255 unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
256 70, 80, 80, 90, 90, 100};
257 /* 5-7, 30-32, 65-68 */
258 struct damon_addr_range new_three_regions[3] = {
259 (struct damon_addr_range){.start = 5, .end = 7},
260 (struct damon_addr_range){.start = 30, .end = 32},
261 (struct damon_addr_range){.start = 65, .end = 68} };
262 /* expect 5-7, 30-32, 65-68 */
263 unsigned long expected[] = {5, 7, 30, 32, 65, 68};
264
265 damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
266 new_three_regions, expected, ARRAY_SIZE(expected));
267 }
268
269 static struct kunit_case damon_test_cases[] = {
270 KUNIT_CASE(damon_test_three_regions_in_vmas),
271 KUNIT_CASE(damon_test_apply_three_regions1),
272 KUNIT_CASE(damon_test_apply_three_regions2),
273 KUNIT_CASE(damon_test_apply_three_regions3),
274 KUNIT_CASE(damon_test_apply_three_regions4),
275 {},
276 };
277
278 static struct kunit_suite damon_test_suite = {
279 .name = "damon-operations",
280 .test_cases = damon_test_cases,
281 };
282 kunit_test_suite(damon_test_suite);
283
284 #endif /* _DAMON_VADDR_TEST_H */
285
286 #endif /* CONFIG_DAMON_VADDR_KUNIT_TEST */
287