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