Commit | Line | Data |
---|---|---|
fe3b1bf1 DC |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | #define _GNU_SOURCE | |
3 | ||
4 | #include <linux/limits.h> | |
5 | #include <unistd.h> | |
6 | #include <stdio.h> | |
a549f9f3 DC |
7 | #include <signal.h> |
8 | #include <sys/sysinfo.h> | |
9 | #include <string.h> | |
10 | #include <sys/wait.h> | |
11 | #include <sys/mman.h> | |
fe3b1bf1 DC |
12 | |
13 | #include "../kselftest.h" | |
14 | #include "cgroup_util.h" | |
15 | ||
a549f9f3 DC |
16 | static int read_int(const char *path, size_t *value) |
17 | { | |
18 | FILE *file; | |
19 | int ret = 0; | |
20 | ||
21 | file = fopen(path, "r"); | |
22 | if (!file) | |
23 | return -1; | |
24 | if (fscanf(file, "%ld", value) != 1) | |
25 | ret = -1; | |
26 | fclose(file); | |
27 | return ret; | |
28 | } | |
29 | ||
30 | static int set_min_free_kb(size_t value) | |
31 | { | |
32 | FILE *file; | |
33 | int ret; | |
34 | ||
35 | file = fopen("/proc/sys/vm/min_free_kbytes", "w"); | |
36 | if (!file) | |
37 | return -1; | |
38 | ret = fprintf(file, "%ld\n", value); | |
39 | fclose(file); | |
40 | return ret; | |
41 | } | |
42 | ||
43 | static int read_min_free_kb(size_t *value) | |
44 | { | |
45 | return read_int("/proc/sys/vm/min_free_kbytes", value); | |
46 | } | |
47 | ||
48 | static int get_zswap_stored_pages(size_t *value) | |
49 | { | |
50 | return read_int("/sys/kernel/debug/zswap/stored_pages", value); | |
51 | } | |
52 | ||
a697dc2b | 53 | static int get_cg_wb_count(const char *cg) |
d9cfaf40 | 54 | { |
012688f6 | 55 | return cg_read_key_long(cg, "memory.stat", "zswpwb"); |
d9cfaf40 DC |
56 | } |
57 | ||
6479b292 NP |
58 | static long get_zswpout(const char *cgroup) |
59 | { | |
60 | return cg_read_key_long(cgroup, "memory.stat", "zswpout "); | |
61 | } | |
62 | ||
b93c28ff NP |
63 | static int allocate_and_read_bytes(const char *cgroup, void *arg) |
64 | { | |
65 | size_t size = (size_t)arg; | |
66 | char *mem = (char *)malloc(size); | |
67 | int ret = 0; | |
68 | ||
69 | if (!mem) | |
70 | return -1; | |
71 | for (int i = 0; i < size; i += 4095) | |
72 | mem[i] = 'a'; | |
73 | ||
74 | /* Go through the allocated memory to (z)swap in and out pages */ | |
75 | for (int i = 0; i < size; i += 4095) { | |
76 | if (mem[i] != 'a') | |
77 | ret = -1; | |
78 | } | |
79 | ||
80 | free(mem); | |
81 | return ret; | |
82 | } | |
83 | ||
d9cfaf40 DC |
84 | static int allocate_bytes(const char *cgroup, void *arg) |
85 | { | |
86 | size_t size = (size_t)arg; | |
87 | char *mem = (char *)malloc(size); | |
88 | ||
89 | if (!mem) | |
90 | return -1; | |
91 | for (int i = 0; i < size; i += 4095) | |
92 | mem[i] = 'a'; | |
93 | free(mem); | |
94 | return 0; | |
95 | } | |
96 | ||
a697dc2b DC |
97 | static char *setup_test_group_1M(const char *root, const char *name) |
98 | { | |
99 | char *group_name = cg_name(root, name); | |
100 | ||
101 | if (!group_name) | |
102 | return NULL; | |
103 | if (cg_create(group_name)) | |
104 | goto fail; | |
105 | if (cg_write(group_name, "memory.max", "1M")) { | |
106 | cg_destroy(group_name); | |
107 | goto fail; | |
108 | } | |
109 | return group_name; | |
110 | fail: | |
111 | free(group_name); | |
112 | return NULL; | |
113 | } | |
114 | ||
6479b292 NP |
115 | /* |
116 | * Sanity test to check that pages are written into zswap. | |
117 | */ | |
118 | static int test_zswap_usage(const char *root) | |
119 | { | |
120 | long zswpout_before, zswpout_after; | |
121 | int ret = KSFT_FAIL; | |
122 | char *test_group; | |
123 | ||
6479b292 NP |
124 | test_group = cg_name(root, "no_shrink_test"); |
125 | if (!test_group) | |
126 | goto out; | |
127 | if (cg_create(test_group)) | |
128 | goto out; | |
129 | if (cg_write(test_group, "memory.max", "1M")) | |
130 | goto out; | |
131 | ||
132 | zswpout_before = get_zswpout(test_group); | |
133 | if (zswpout_before < 0) { | |
134 | ksft_print_msg("Failed to get zswpout\n"); | |
135 | goto out; | |
136 | } | |
137 | ||
138 | /* Allocate more than memory.max to push memory into zswap */ | |
139 | if (cg_run(test_group, allocate_bytes, (void *)MB(4))) | |
140 | goto out; | |
141 | ||
142 | /* Verify that pages come into zswap */ | |
143 | zswpout_after = get_zswpout(test_group); | |
144 | if (zswpout_after <= zswpout_before) { | |
145 | ksft_print_msg("zswpout does not increase after test program\n"); | |
146 | goto out; | |
147 | } | |
148 | ret = KSFT_PASS; | |
149 | ||
150 | out: | |
151 | cg_destroy(test_group); | |
152 | free(test_group); | |
153 | return ret; | |
154 | } | |
155 | ||
b93c28ff NP |
156 | /* |
157 | * Check that when memory.zswap.max = 0, no pages can go to the zswap pool for | |
158 | * the cgroup. | |
159 | */ | |
160 | static int test_swapin_nozswap(const char *root) | |
161 | { | |
162 | int ret = KSFT_FAIL; | |
163 | char *test_group; | |
164 | long swap_peak, zswpout; | |
165 | ||
166 | test_group = cg_name(root, "no_zswap_test"); | |
167 | if (!test_group) | |
168 | goto out; | |
169 | if (cg_create(test_group)) | |
170 | goto out; | |
171 | if (cg_write(test_group, "memory.max", "8M")) | |
172 | goto out; | |
173 | if (cg_write(test_group, "memory.zswap.max", "0")) | |
174 | goto out; | |
175 | ||
176 | /* Allocate and read more than memory.max to trigger swapin */ | |
177 | if (cg_run(test_group, allocate_and_read_bytes, (void *)MB(32))) | |
178 | goto out; | |
179 | ||
180 | /* Verify that pages are swapped out, but no zswap happened */ | |
181 | swap_peak = cg_read_long(test_group, "memory.swap.peak"); | |
182 | if (swap_peak < 0) { | |
183 | ksft_print_msg("failed to get cgroup's swap_peak\n"); | |
184 | goto out; | |
185 | } | |
186 | ||
187 | if (swap_peak < MB(24)) { | |
188 | ksft_print_msg("at least 24MB of memory should be swapped out\n"); | |
189 | goto out; | |
190 | } | |
191 | ||
192 | zswpout = get_zswpout(test_group); | |
193 | if (zswpout < 0) { | |
194 | ksft_print_msg("failed to get zswpout\n"); | |
195 | goto out; | |
196 | } | |
197 | ||
198 | if (zswpout > 0) { | |
199 | ksft_print_msg("zswapout > 0 when memory.zswap.max = 0\n"); | |
200 | goto out; | |
201 | } | |
202 | ||
203 | ret = KSFT_PASS; | |
204 | ||
205 | out: | |
206 | cg_destroy(test_group); | |
207 | free(test_group); | |
208 | return ret; | |
209 | } | |
210 | ||
211 | /* Simple test to verify the (z)swapin code paths */ | |
212 | static int test_zswapin(const char *root) | |
213 | { | |
214 | int ret = KSFT_FAIL; | |
215 | char *test_group; | |
216 | long zswpin; | |
217 | ||
218 | test_group = cg_name(root, "zswapin_test"); | |
219 | if (!test_group) | |
220 | goto out; | |
221 | if (cg_create(test_group)) | |
222 | goto out; | |
223 | if (cg_write(test_group, "memory.max", "8M")) | |
224 | goto out; | |
225 | if (cg_write(test_group, "memory.zswap.max", "max")) | |
226 | goto out; | |
227 | ||
228 | /* Allocate and read more than memory.max to trigger (z)swap in */ | |
229 | if (cg_run(test_group, allocate_and_read_bytes, (void *)MB(32))) | |
230 | goto out; | |
231 | ||
232 | zswpin = cg_read_key_long(test_group, "memory.stat", "zswpin "); | |
233 | if (zswpin < 0) { | |
234 | ksft_print_msg("failed to get zswpin\n"); | |
235 | goto out; | |
236 | } | |
237 | ||
238 | if (zswpin < MB(24) / PAGE_SIZE) { | |
239 | ksft_print_msg("at least 24MB should be brought back from zswap\n"); | |
240 | goto out; | |
241 | } | |
242 | ||
243 | ret = KSFT_PASS; | |
244 | ||
245 | out: | |
246 | cg_destroy(test_group); | |
247 | free(test_group); | |
248 | return ret; | |
249 | } | |
250 | ||
d9cfaf40 DC |
251 | /* |
252 | * When trying to store a memcg page in zswap, if the memcg hits its memory | |
a697dc2b DC |
253 | * limit in zswap, writeback should affect only the zswapped pages of that |
254 | * memcg. | |
d9cfaf40 DC |
255 | */ |
256 | static int test_no_invasive_cgroup_shrink(const char *root) | |
257 | { | |
d9cfaf40 | 258 | int ret = KSFT_FAIL; |
a697dc2b DC |
259 | size_t control_allocation_size = MB(10); |
260 | char *control_allocation, *wb_group = NULL, *control_group = NULL; | |
d9cfaf40 | 261 | |
a697dc2b DC |
262 | wb_group = setup_test_group_1M(root, "per_memcg_wb_test1"); |
263 | if (!wb_group) | |
264 | return KSFT_FAIL; | |
265 | if (cg_write(wb_group, "memory.zswap.max", "10K")) | |
d9cfaf40 | 266 | goto out; |
a697dc2b DC |
267 | control_group = setup_test_group_1M(root, "per_memcg_wb_test2"); |
268 | if (!control_group) | |
d9cfaf40 | 269 | goto out; |
a697dc2b DC |
270 | |
271 | /* Push some test_group2 memory into zswap */ | |
272 | if (cg_enter_current(control_group)) | |
d9cfaf40 | 273 | goto out; |
a697dc2b DC |
274 | control_allocation = malloc(control_allocation_size); |
275 | for (int i = 0; i < control_allocation_size; i += 4095) | |
276 | control_allocation[i] = 'a'; | |
277 | if (cg_read_key_long(control_group, "memory.stat", "zswapped") < 1) | |
d9cfaf40 DC |
278 | goto out; |
279 | ||
a697dc2b DC |
280 | /* Allocate 10x memory.max to push wb_group memory into zswap and trigger wb */ |
281 | if (cg_run(wb_group, allocate_bytes, (void *)MB(10))) | |
d9cfaf40 DC |
282 | goto out; |
283 | ||
a697dc2b DC |
284 | /* Verify that only zswapped memory from gwb_group has been written back */ |
285 | if (get_cg_wb_count(wb_group) > 0 && get_cg_wb_count(control_group) == 0) | |
d9cfaf40 DC |
286 | ret = KSFT_PASS; |
287 | out: | |
a697dc2b DC |
288 | cg_enter_current(root); |
289 | if (control_group) { | |
290 | cg_destroy(control_group); | |
291 | free(control_group); | |
292 | } | |
293 | cg_destroy(wb_group); | |
294 | free(wb_group); | |
295 | if (control_allocation) | |
296 | free(control_allocation); | |
d9cfaf40 DC |
297 | return ret; |
298 | } | |
299 | ||
a549f9f3 DC |
300 | struct no_kmem_bypass_child_args { |
301 | size_t target_alloc_bytes; | |
302 | size_t child_allocated; | |
303 | }; | |
304 | ||
305 | static int no_kmem_bypass_child(const char *cgroup, void *arg) | |
306 | { | |
307 | struct no_kmem_bypass_child_args *values = arg; | |
308 | void *allocation; | |
309 | ||
310 | allocation = malloc(values->target_alloc_bytes); | |
311 | if (!allocation) { | |
312 | values->child_allocated = true; | |
313 | return -1; | |
314 | } | |
315 | for (long i = 0; i < values->target_alloc_bytes; i += 4095) | |
316 | ((char *)allocation)[i] = 'a'; | |
317 | values->child_allocated = true; | |
318 | pause(); | |
319 | free(allocation); | |
320 | return 0; | |
321 | } | |
322 | ||
323 | /* | |
324 | * When pages owned by a memcg are pushed to zswap by kswapd, they should be | |
325 | * charged to that cgroup. This wasn't the case before commit | |
326 | * cd08d80ecdac("mm: correctly charge compressed memory to its memcg"). | |
327 | * | |
328 | * The test first allocates memory in a memcg, then raises min_free_kbytes to | |
329 | * a very high value so that the allocation falls below low wm, then makes | |
330 | * another allocation to trigger kswapd that should push the memcg-owned pages | |
331 | * to zswap and verifies that the zswap pages are correctly charged. | |
332 | * | |
333 | * To be run on a VM with at most 4G of memory. | |
334 | */ | |
335 | static int test_no_kmem_bypass(const char *root) | |
336 | { | |
337 | size_t min_free_kb_high, min_free_kb_low, min_free_kb_original; | |
338 | struct no_kmem_bypass_child_args *values; | |
339 | size_t trigger_allocation_size; | |
340 | int wait_child_iteration = 0; | |
341 | long stored_pages_threshold; | |
342 | struct sysinfo sys_info; | |
343 | int ret = KSFT_FAIL; | |
344 | int child_status; | |
345 | char *test_group; | |
346 | pid_t child_pid; | |
347 | ||
348 | /* Read sys info and compute test values accordingly */ | |
349 | if (sysinfo(&sys_info) != 0) | |
350 | return KSFT_FAIL; | |
351 | if (sys_info.totalram > 5000000000) | |
352 | return KSFT_SKIP; | |
353 | values = mmap(0, sizeof(struct no_kmem_bypass_child_args), PROT_READ | | |
354 | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0); | |
355 | if (values == MAP_FAILED) | |
356 | return KSFT_FAIL; | |
357 | if (read_min_free_kb(&min_free_kb_original)) | |
358 | return KSFT_FAIL; | |
359 | min_free_kb_high = sys_info.totalram / 2000; | |
360 | min_free_kb_low = sys_info.totalram / 500000; | |
361 | values->target_alloc_bytes = (sys_info.totalram - min_free_kb_high * 1000) + | |
362 | sys_info.totalram * 5 / 100; | |
363 | stored_pages_threshold = sys_info.totalram / 5 / 4096; | |
364 | trigger_allocation_size = sys_info.totalram / 20; | |
365 | ||
366 | /* Set up test memcg */ | |
367 | if (cg_write(root, "cgroup.subtree_control", "+memory")) | |
368 | goto out; | |
369 | test_group = cg_name(root, "kmem_bypass_test"); | |
370 | if (!test_group) | |
371 | goto out; | |
372 | ||
373 | /* Spawn memcg child and wait for it to allocate */ | |
374 | set_min_free_kb(min_free_kb_low); | |
375 | if (cg_create(test_group)) | |
376 | goto out; | |
377 | values->child_allocated = false; | |
378 | child_pid = cg_run_nowait(test_group, no_kmem_bypass_child, values); | |
379 | if (child_pid < 0) | |
380 | goto out; | |
381 | while (!values->child_allocated && wait_child_iteration++ < 10000) | |
382 | usleep(1000); | |
383 | ||
384 | /* Try to wakeup kswapd and let it push child memory to zswap */ | |
385 | set_min_free_kb(min_free_kb_high); | |
386 | for (int i = 0; i < 20; i++) { | |
387 | size_t stored_pages; | |
388 | char *trigger_allocation = malloc(trigger_allocation_size); | |
389 | ||
390 | if (!trigger_allocation) | |
391 | break; | |
392 | for (int i = 0; i < trigger_allocation_size; i += 4095) | |
393 | trigger_allocation[i] = 'b'; | |
394 | usleep(100000); | |
395 | free(trigger_allocation); | |
396 | if (get_zswap_stored_pages(&stored_pages)) | |
397 | break; | |
398 | if (stored_pages < 0) | |
399 | break; | |
400 | /* If memory was pushed to zswap, verify it belongs to memcg */ | |
401 | if (stored_pages > stored_pages_threshold) { | |
402 | int zswapped = cg_read_key_long(test_group, "memory.stat", "zswapped "); | |
403 | int delta = stored_pages * 4096 - zswapped; | |
404 | int result_ok = delta < stored_pages * 4096 / 4; | |
405 | ||
406 | ret = result_ok ? KSFT_PASS : KSFT_FAIL; | |
407 | break; | |
408 | } | |
409 | } | |
410 | ||
411 | kill(child_pid, SIGTERM); | |
412 | waitpid(child_pid, &child_status, 0); | |
413 | out: | |
414 | set_min_free_kb(min_free_kb_original); | |
415 | cg_destroy(test_group); | |
416 | free(test_group); | |
417 | return ret; | |
418 | } | |
419 | ||
fe3b1bf1 DC |
420 | #define T(x) { x, #x } |
421 | struct zswap_test { | |
422 | int (*fn)(const char *root); | |
423 | const char *name; | |
424 | } tests[] = { | |
6479b292 | 425 | T(test_zswap_usage), |
b93c28ff NP |
426 | T(test_swapin_nozswap), |
427 | T(test_zswapin), | |
a549f9f3 | 428 | T(test_no_kmem_bypass), |
d9cfaf40 | 429 | T(test_no_invasive_cgroup_shrink), |
fe3b1bf1 DC |
430 | }; |
431 | #undef T | |
432 | ||
433 | static bool zswap_configured(void) | |
434 | { | |
435 | return access("/sys/module/zswap", F_OK) == 0; | |
436 | } | |
437 | ||
438 | int main(int argc, char **argv) | |
439 | { | |
440 | char root[PATH_MAX]; | |
441 | int i, ret = EXIT_SUCCESS; | |
442 | ||
443 | if (cg_find_unified_root(root, sizeof(root))) | |
444 | ksft_exit_skip("cgroup v2 isn't mounted\n"); | |
445 | ||
446 | if (!zswap_configured()) | |
447 | ksft_exit_skip("zswap isn't configured\n"); | |
448 | ||
449 | /* | |
450 | * Check that memory controller is available: | |
451 | * memory is listed in cgroup.controllers | |
452 | */ | |
453 | if (cg_read_strstr(root, "cgroup.controllers", "memory")) | |
454 | ksft_exit_skip("memory controller isn't available\n"); | |
455 | ||
456 | if (cg_read_strstr(root, "cgroup.subtree_control", "memory")) | |
457 | if (cg_write(root, "cgroup.subtree_control", "+memory")) | |
458 | ksft_exit_skip("Failed to set memory controller\n"); | |
459 | ||
460 | for (i = 0; i < ARRAY_SIZE(tests); i++) { | |
461 | switch (tests[i].fn(root)) { | |
462 | case KSFT_PASS: | |
463 | ksft_test_result_pass("%s\n", tests[i].name); | |
464 | break; | |
465 | case KSFT_SKIP: | |
466 | ksft_test_result_skip("%s\n", tests[i].name); | |
467 | break; | |
468 | default: | |
469 | ret = EXIT_FAILURE; | |
470 | ksft_test_result_fail("%s\n", tests[i].name); | |
471 | break; | |
472 | } | |
473 | } | |
474 | ||
475 | return ret; | |
476 | } |