1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Data Access Monitor Unit Tests
4 *
5 * Copyright 2019 Amazon.com, Inc. or its affiliates. All rights reserved.
6 *
7 * Author: SeongJae Park <sj@kernel.org>
8 */
9
10 #ifdef CONFIG_DAMON_VADDR_KUNIT_TEST
11
12 #ifndef _DAMON_VADDR_TEST_H
13 #define _DAMON_VADDR_TEST_H
14
15 #include <kunit/test.h>
16
17 static int __link_vmas(struct maple_tree *mt, struct vm_area_struct *vmas,
18 ssize_t nr_vmas)
19 {
20 int i, ret = -ENOMEM;
21 MA_STATE(mas, mt, 0, 0);
22
23 if (!nr_vmas)
24 return 0;
25
26 mas_lock(&mas);
27 for (i = 0; i < nr_vmas; i++) {
28 mas_set_range(&mas, vmas[i].vm_start, vmas[i].vm_end - 1);
29 if (mas_store_gfp(&mas, &vmas[i], GFP_KERNEL))
30 goto failed;
31 }
32
33 ret = 0;
34 failed:
35 mas_unlock(&mas);
36 return ret;
37 }
38
39 /*
40 * Test __damon_va_three_regions() function
41 *
42 * In case of virtual memory address spaces monitoring, DAMON converts the
43 * complex and dynamic memory mappings of each target task to three
44 * discontiguous regions which cover every mapped areas. However, the three
45 * regions should not include the two biggest unmapped areas in the original
46 * mapping, because the two biggest areas are normally the areas between 1)
47 * heap and the mmap()-ed regions, and 2) the mmap()-ed regions and stack.
48 * Because these two unmapped areas are very huge but obviously never accessed,
49 * covering the region is just a waste.
50 *
51 * '__damon_va_three_regions() receives an address space of a process. It
52 * first identifies the start of mappings, end of mappings, and the two biggest
53 * unmapped areas. After that, based on the information, it constructs the
54 * three regions and returns. For more detail, refer to the comment of
55 * 'damon_init_regions_of()' function definition in 'mm/damon.c' file.
56 *
57 * For example, suppose virtual address ranges of 10-20, 20-25, 200-210,
58 * 210-220, 300-305, and 307-330 (Other comments represent this mappings in
59 * more short form: 10-20-25, 200-210-220, 300-305, 307-330) of a process are
60 * mapped. To cover every mappings, the three regions should start with 10,
61 * and end with 305. The process also has three unmapped areas, 25-200,
62 * 220-300, and 305-307. Among those, 25-200 and 220-300 are the biggest two
63 * unmapped areas, and thus it should be converted to three regions of 10-25,
64 * 200-220, and 300-330.
65 */
66 static void damon_test_three_regions_in_vmas(struct kunit *test)
67 {
68 static struct mm_struct mm;
69 struct damon_addr_range regions[3] = {0,};
70 /* 10-20-25, 200-210-220, 300-305, 307-330 */
71 struct vm_area_struct vmas[] = {
72 (struct vm_area_struct) {.vm_start = 10, .vm_end = 20},
73 (struct vm_area_struct) {.vm_start = 20, .vm_end = 25},
74 (struct vm_area_struct) {.vm_start = 200, .vm_end = 210},
75 (struct vm_area_struct) {.vm_start = 210, .vm_end = 220},
76 (struct vm_area_struct) {.vm_start = 300, .vm_end = 305},
77 (struct vm_area_struct) {.vm_start = 307, .vm_end = 330},
78 };
79
80 mt_init_flags(&mm.mm_mt, MM_MT_FLAGS);
81 if (__link_vmas(&mm.mm_mt, vmas, ARRAY_SIZE(vmas)))
82 kunit_skip(test, "Failed to create VMA tree");
83
84 __damon_va_three_regions(&mm, regions);
85
86 KUNIT_EXPECT_EQ(test, 10ul, regions[0].start);
87 KUNIT_EXPECT_EQ(test, 25ul, regions[0].end);
88 KUNIT_EXPECT_EQ(test, 200ul, regions[1].start);
89 KUNIT_EXPECT_EQ(test, 220ul, regions[1].end);
90 KUNIT_EXPECT_EQ(test, 300ul, regions[2].start);
91 KUNIT_EXPECT_EQ(test, 330ul, regions[2].end);
92 }
93
94 static struct damon_region *__nth_region_of(struct damon_target *t, int idx)
95 {
96 struct damon_region *r;
97 unsigned int i = 0;
98
99 damon_for_each_region(r, t) {
100 if (i++ == idx)
101 return r;
102 }
103
104 return NULL;
105 }
106
107 /*
108 * Test 'damon_set_regions()'
109 *
110 * test kunit object
111 * regions an array containing start/end addresses of current
112 * monitoring target regions
113 * nr_regions the number of the addresses in 'regions'
114 * three_regions The three regions that need to be applied now
115 * expected start/end addresses of monitoring target regions that
116 * 'three_regions' are applied
117 * nr_expected the number of addresses in 'expected'
118 *
119 * The memory mapping of the target processes changes dynamically. To follow
120 * the change, DAMON periodically reads the mappings, simplifies it to the
121 * three regions, and updates the monitoring target regions to fit in the three
122 * regions. The update of current target regions is the role of
123 * 'damon_set_regions()'.
124 *
125 * This test passes the given target regions and the new three regions that
126 * need to be applied to the function and check whether it updates the regions
127 * as expected.
128 */
129 static void damon_do_test_apply_three_regions(struct kunit *test,
130 unsigned long *regions, int nr_regions,
131 struct damon_addr_range *three_regions,
132 unsigned long *expected, int nr_expected)
133 {
134 struct damon_target *t;
135 struct damon_region *r;
136 int i;
137
138 t = damon_new_target();
139 for (i = 0; i < nr_regions / 2; i++) {
140 r = damon_new_region(regions[i * 2], regions[i * 2 + 1]);
141 damon_add_region(r, t);
142 }
143
144 damon_set_regions(t, three_regions, 3);
145
146 for (i = 0; i < nr_expected / 2; i++) {
147 r = __nth_region_of(t, i);
148 KUNIT_EXPECT_EQ(test, r->ar.start, expected[i * 2]);
149 KUNIT_EXPECT_EQ(test, r->ar.end, expected[i * 2 + 1]);
150 }
151
152 damon_destroy_target(t);
153 }
154
155 /*
156 * This function test most common case where the three big regions are only
157 * slightly changed. Target regions should adjust their boundary (10-20-30,
158 * 50-55, 70-80, 90-100) to fit with the new big regions or remove target
159 * regions (57-79) that now out of the three regions.
160 */
161 static void damon_test_apply_three_regions1(struct kunit *test)
162 {
163 /* 10-20-30, 50-55-57-59, 70-80-90-100 */
164 unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
165 70, 80, 80, 90, 90, 100};
166 /* 5-27, 45-55, 73-104 */
167 struct damon_addr_range new_three_regions[3] = {
168 (struct damon_addr_range){.start = 5, .end = 27},
169 (struct damon_addr_range){.start = 45, .end = 55},
170 (struct damon_addr_range){.start = 73, .end = 104} };
171 /* 5-20-27, 45-55, 73-80-90-104 */
172 unsigned long expected[] = {5, 20, 20, 27, 45, 55,
173 73, 80, 80, 90, 90, 104};
174
175 damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
176 new_three_regions, expected, ARRAY_SIZE(expected));
177 }
178
179 /*
180 * Test slightly bigger change. Similar to above, but the second big region
181 * now require two target regions (50-55, 57-59) to be removed.
182 */
183 static void damon_test_apply_three_regions2(struct kunit *test)
184 {
185 /* 10-20-30, 50-55-57-59, 70-80-90-100 */
186 unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
187 70, 80, 80, 90, 90, 100};
188 /* 5-27, 56-57, 65-104 */
189 struct damon_addr_range new_three_regions[3] = {
190 (struct damon_addr_range){.start = 5, .end = 27},
191 (struct damon_addr_range){.start = 56, .end = 57},
192 (struct damon_addr_range){.start = 65, .end = 104} };
193 /* 5-20-27, 56-57, 65-80-90-104 */
194 unsigned long expected[] = {5, 20, 20, 27, 56, 57,
195 65, 80, 80, 90, 90, 104};
196
197 damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
198 new_three_regions, expected, ARRAY_SIZE(expected));
199 }
200
201 /*
202 * Test a big change. The second big region has totally freed and mapped to
203 * different area (50-59 -> 61-63). The target regions which were in the old
204 * second big region (50-55-57-59) should be removed and new target region
205 * covering the second big region (61-63) should be created.
206 */
207 static void damon_test_apply_three_regions3(struct kunit *test)
208 {
209 /* 10-20-30, 50-55-57-59, 70-80-90-100 */
210 unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
211 70, 80, 80, 90, 90, 100};
212 /* 5-27, 61-63, 65-104 */
213 struct damon_addr_range new_three_regions[3] = {
214 (struct damon_addr_range){.start = 5, .end = 27},
215 (struct damon_addr_range){.start = 61, .end = 63},
216 (struct damon_addr_range){.start = 65, .end = 104} };
217 /* 5-20-27, 61-63, 65-80-90-104 */
218 unsigned long expected[] = {5, 20, 20, 27, 61, 63,
219 65, 80, 80, 90, 90, 104};
220
221 damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
222 new_three_regions, expected, ARRAY_SIZE(expected));
223 }
224
225 /*
226 * Test another big change. Both of the second and third big regions (50-59
227 * and 70-100) has totally freed and mapped to different area (30-32 and
228 * 65-68). The target regions which were in the old second and third big
229 * regions should now be removed and new target regions covering the new second
230 * and third big regions should be created.
231 */
232 static void damon_test_apply_three_regions4(struct kunit *test)
233 {
234 /* 10-20-30, 50-55-57-59, 70-80-90-100 */
235 unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
236 70, 80, 80, 90, 90, 100};
237 /* 5-7, 30-32, 65-68 */
238 struct damon_addr_range new_three_regions[3] = {
239 (struct damon_addr_range){.start = 5, .end = 7},
240 (struct damon_addr_range){.start = 30, .end = 32},
241 (struct damon_addr_range){.start = 65, .end = 68} };
242 /* expect 5-7, 30-32, 65-68 */
243 unsigned long expected[] = {5, 7, 30, 32, 65, 68};
244
245 damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
246 new_three_regions, expected, ARRAY_SIZE(expected));
247 }
248
249 static void damon_test_split_evenly_fail(struct kunit *test,
250 unsigned long start, unsigned long end, unsigned int nr_pieces)
251 {
252 struct damon_target *t = damon_new_target();
253 struct damon_region *r = damon_new_region(start, end);
254
255 damon_add_region(r, t);
256 KUNIT_EXPECT_EQ(test,
257 damon_va_evenly_split_region(t, r, nr_pieces), -EINVAL);
258 KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 1u);
259
260 damon_for_each_region(r, t) {
261 KUNIT_EXPECT_EQ(test, r->ar.start, start);
262 KUNIT_EXPECT_EQ(test, r->ar.end, end);
263 }
264
265 damon_free_target(t);
266 }
267
268 static void damon_test_split_evenly_succ(struct kunit *test,
269 unsigned long start, unsigned long end, unsigned int nr_pieces)
270 {
271 struct damon_target *t = damon_new_target();
272 struct damon_region *r = damon_new_region(start, end);
273 unsigned long expected_width = (end - start) / nr_pieces;
274 unsigned long i = 0;
275
276 damon_add_region(r, t);
277 KUNIT_EXPECT_EQ(test,
278 damon_va_evenly_split_region(t, r, nr_pieces), 0);
279 KUNIT_EXPECT_EQ(test, damon_nr_regions(t), nr_pieces);
280
281 damon_for_each_region(r, t) {
282 if (i == nr_pieces - 1) {
283 KUNIT_EXPECT_EQ(test,
284 r->ar.start, start + i * expected_width);
285 KUNIT_EXPECT_EQ(test, r->ar.end, end);
286 break;
287 }
288 KUNIT_EXPECT_EQ(test,
289 r->ar.start, start + i++ * expected_width);
290 KUNIT_EXPECT_EQ(test, r->ar.end, start + i * expected_width);
291 }
292 damon_free_target(t);
293 }
294
295 static void damon_test_split_evenly(struct kunit *test)
296 {
297 KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(NULL, NULL, 5),
298 -EINVAL);
299
300 damon_test_split_evenly_fail(test, 0, 100, 0);
301 damon_test_split_evenly_succ(test, 0, 100, 10);
302 damon_test_split_evenly_succ(test, 5, 59, 5);
303 damon_test_split_evenly_fail(test, 5, 6, 2);
304 }
305
306 static struct kunit_case damon_test_cases[] = {
307 KUNIT_CASE(damon_test_three_regions_in_vmas),
308 KUNIT_CASE(damon_test_apply_three_regions1),
309 KUNIT_CASE(damon_test_apply_three_regions2),
310 KUNIT_CASE(damon_test_apply_three_regions3),
311 KUNIT_CASE(damon_test_apply_three_regions4),
312 KUNIT_CASE(damon_test_split_evenly),
313 {},
314 };
315
316 static struct kunit_suite damon_test_suite = {
317 .name = "damon-operations",
318 .test_cases = damon_test_cases,
319 };
320 kunit_test_suite(damon_test_suite);
321
322 #endif /* _DAMON_VADDR_TEST_H */
323
324 #endif /* CONFIG_DAMON_VADDR_KUNIT_TEST */
325
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