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