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
__link_vmas(struct maple_tree * mt,struct vm_area_struct * vmas,ssize_t nr_vmas)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 */
damon_test_three_regions_in_vmas(struct kunit * test)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 static 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, MT_FLAGS_ALLOC_RANGE | MT_FLAGS_USE_RCU);
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
__nth_region_of(struct damon_target * t,int idx)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 */
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)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 if (!t)
140 kunit_skip(test, "target alloc fail");
141 for (i = 0; i < nr_regions / 2; i++) {
142 r = damon_new_region(regions[i * 2], regions[i * 2 + 1]);
143 if (!r) {
144 damon_destroy_target(t, NULL);
145 kunit_skip(test, "region alloc fail");
146 }
147 damon_add_region(r, t);
148 }
149
150 damon_set_regions(t, three_regions, 3, DAMON_MIN_REGION);
151
152 for (i = 0; i < nr_expected / 2; i++) {
153 r = __nth_region_of(t, i);
154 KUNIT_EXPECT_EQ(test, r->ar.start, expected[i * 2]);
155 KUNIT_EXPECT_EQ(test, r->ar.end, expected[i * 2 + 1]);
156 }
157
158 damon_destroy_target(t, NULL);
159 }
160
161 /*
162 * This function test most common case where the three big regions are only
163 * slightly changed. Target regions should adjust their boundary (10-20-30,
164 * 50-55, 70-80, 90-100) to fit with the new big regions or remove target
165 * regions (57-79) that now out of the three regions.
166 */
damon_test_apply_three_regions1(struct kunit * test)167 static void damon_test_apply_three_regions1(struct kunit *test)
168 {
169 /* 10-20-30, 50-55-57-59, 70-80-90-100 */
170 unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
171 70, 80, 80, 90, 90, 100};
172 /* 5-27, 45-55, 73-104 */
173 struct damon_addr_range new_three_regions[3] = {
174 (struct damon_addr_range){.start = 5, .end = 27},
175 (struct damon_addr_range){.start = 45, .end = 55},
176 (struct damon_addr_range){.start = 73, .end = 104} };
177 /* 5-20-27, 45-55, 73-80-90-104 */
178 unsigned long expected[] = {5, 20, 20, 27, 45, 55,
179 73, 80, 80, 90, 90, 104};
180
181 damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
182 new_three_regions, expected, ARRAY_SIZE(expected));
183 }
184
185 /*
186 * Test slightly bigger change. Similar to above, but the second big region
187 * now require two target regions (50-55, 57-59) to be removed.
188 */
damon_test_apply_three_regions2(struct kunit * test)189 static void damon_test_apply_three_regions2(struct kunit *test)
190 {
191 /* 10-20-30, 50-55-57-59, 70-80-90-100 */
192 unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
193 70, 80, 80, 90, 90, 100};
194 /* 5-27, 56-57, 65-104 */
195 struct damon_addr_range new_three_regions[3] = {
196 (struct damon_addr_range){.start = 5, .end = 27},
197 (struct damon_addr_range){.start = 56, .end = 57},
198 (struct damon_addr_range){.start = 65, .end = 104} };
199 /* 5-20-27, 56-57, 65-80-90-104 */
200 unsigned long expected[] = {5, 20, 20, 27, 56, 57,
201 65, 80, 80, 90, 90, 104};
202
203 damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
204 new_three_regions, expected, ARRAY_SIZE(expected));
205 }
206
207 /*
208 * Test a big change. The second big region has totally freed and mapped to
209 * different area (50-59 -> 61-63). The target regions which were in the old
210 * second big region (50-55-57-59) should be removed and new target region
211 * covering the second big region (61-63) should be created.
212 */
damon_test_apply_three_regions3(struct kunit * test)213 static void damon_test_apply_three_regions3(struct kunit *test)
214 {
215 /* 10-20-30, 50-55-57-59, 70-80-90-100 */
216 unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
217 70, 80, 80, 90, 90, 100};
218 /* 5-27, 61-63, 65-104 */
219 struct damon_addr_range new_three_regions[3] = {
220 (struct damon_addr_range){.start = 5, .end = 27},
221 (struct damon_addr_range){.start = 61, .end = 63},
222 (struct damon_addr_range){.start = 65, .end = 104} };
223 /* 5-20-27, 61-63, 65-80-90-104 */
224 unsigned long expected[] = {5, 20, 20, 27, 61, 63,
225 65, 80, 80, 90, 90, 104};
226
227 damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
228 new_three_regions, expected, ARRAY_SIZE(expected));
229 }
230
231 /*
232 * Test another big change. Both of the second and third big regions (50-59
233 * and 70-100) has totally freed and mapped to different area (30-32 and
234 * 65-68). The target regions which were in the old second and third big
235 * regions should now be removed and new target regions covering the new second
236 * and third big regions should be created.
237 */
damon_test_apply_three_regions4(struct kunit * test)238 static void damon_test_apply_three_regions4(struct kunit *test)
239 {
240 /* 10-20-30, 50-55-57-59, 70-80-90-100 */
241 unsigned long regions[] = {10, 20, 20, 30, 50, 55, 55, 57, 57, 59,
242 70, 80, 80, 90, 90, 100};
243 /* 5-7, 30-32, 65-68 */
244 struct damon_addr_range new_three_regions[3] = {
245 (struct damon_addr_range){.start = 5, .end = 7},
246 (struct damon_addr_range){.start = 30, .end = 32},
247 (struct damon_addr_range){.start = 65, .end = 68} };
248 /* expect 5-7, 30-32, 65-68 */
249 unsigned long expected[] = {5, 7, 30, 32, 65, 68};
250
251 damon_do_test_apply_three_regions(test, regions, ARRAY_SIZE(regions),
252 new_three_regions, expected, ARRAY_SIZE(expected));
253 }
254
damon_test_split_evenly_fail(struct kunit * test,unsigned long start,unsigned long end,unsigned int nr_pieces)255 static void damon_test_split_evenly_fail(struct kunit *test,
256 unsigned long start, unsigned long end, unsigned int nr_pieces)
257 {
258 struct damon_target *t = damon_new_target();
259 struct damon_region *r;
260
261 if (!t)
262 kunit_skip(test, "target alloc fail");
263
264 r = damon_new_region(start, end);
265 if (!r) {
266 damon_free_target(t);
267 kunit_skip(test, "region alloc fail");
268 }
269
270 damon_add_region(r, t);
271 KUNIT_EXPECT_EQ(test,
272 damon_va_evenly_split_region(t, r, nr_pieces), -EINVAL);
273 KUNIT_EXPECT_EQ(test, damon_nr_regions(t), 1u);
274
275 damon_for_each_region(r, t) {
276 KUNIT_EXPECT_EQ(test, r->ar.start, start);
277 KUNIT_EXPECT_EQ(test, r->ar.end, end);
278 }
279
280 damon_free_target(t);
281 }
282
damon_test_split_evenly_succ(struct kunit * test,unsigned long start,unsigned long end,unsigned int nr_pieces)283 static void damon_test_split_evenly_succ(struct kunit *test,
284 unsigned long start, unsigned long end, unsigned int nr_pieces)
285 {
286 struct damon_target *t = damon_new_target();
287 struct damon_region *r;
288 unsigned long expected_width = (end - start) / nr_pieces;
289 unsigned long i = 0;
290
291 if (!t)
292 kunit_skip(test, "target alloc fail");
293 r = damon_new_region(start, end);
294 if (!r) {
295 damon_free_target(t);
296 kunit_skip(test, "region alloc fail");
297 }
298 damon_add_region(r, t);
299 KUNIT_EXPECT_EQ(test,
300 damon_va_evenly_split_region(t, r, nr_pieces), 0);
301 KUNIT_EXPECT_EQ(test, damon_nr_regions(t), nr_pieces);
302
303 damon_for_each_region(r, t) {
304 if (i == nr_pieces - 1) {
305 KUNIT_EXPECT_EQ(test,
306 r->ar.start, start + i * expected_width);
307 KUNIT_EXPECT_EQ(test, r->ar.end, end);
308 break;
309 }
310 KUNIT_EXPECT_EQ(test,
311 r->ar.start, start + i++ * expected_width);
312 KUNIT_EXPECT_EQ(test, r->ar.end, start + i * expected_width);
313 }
314 damon_free_target(t);
315 }
316
damon_test_split_evenly(struct kunit * test)317 static void damon_test_split_evenly(struct kunit *test)
318 {
319 KUNIT_EXPECT_EQ(test, damon_va_evenly_split_region(NULL, NULL, 5),
320 -EINVAL);
321
322 damon_test_split_evenly_fail(test, 0, 100, 0);
323 damon_test_split_evenly_succ(test, 0, 100, 10);
324 damon_test_split_evenly_succ(test, 5, 59, 5);
325 damon_test_split_evenly_succ(test, 4, 6, 1);
326 damon_test_split_evenly_succ(test, 0, 3, 2);
327 damon_test_split_evenly_fail(test, 5, 6, 2);
328 }
329
330 static struct kunit_case damon_test_cases[] = {
331 KUNIT_CASE(damon_test_three_regions_in_vmas),
332 KUNIT_CASE(damon_test_apply_three_regions1),
333 KUNIT_CASE(damon_test_apply_three_regions2),
334 KUNIT_CASE(damon_test_apply_three_regions3),
335 KUNIT_CASE(damon_test_apply_three_regions4),
336 KUNIT_CASE(damon_test_split_evenly),
337 {},
338 };
339
340 static struct kunit_suite damon_test_suite = {
341 .name = "damon-operations",
342 .test_cases = damon_test_cases,
343 };
344 kunit_test_suite(damon_test_suite);
345
346 #endif /* _DAMON_VADDR_TEST_H */
347
348 #endif /* CONFIG_DAMON_VADDR_KUNIT_TEST */
349