| 1 | |
| 2 | |
| 3 | * Copyright (C) 2024 Jason A. Donenfeld <[email protected]>. All Rights Reserved.
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| 4 |
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| 5 |
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| 6 | #include <assert.h>
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| 7 | #include <stdbool.h>
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| 8 | #include <stdint.h>
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| 9 | #include <stdio.h>
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| 10 | #include <stdlib.h>
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| 11 | #include <unistd.h>
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| 12 | #include <signal.h>
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| 13 | #include <sys/mman.h>
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| 14 | #include <linux/mman.h>
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| 15 |
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| 16 | #include "kselftest.h"
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| 17 |
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| 18 | int main(int argc, char *argv[])
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| 19 | {
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| 20 | const size_t alloc_size = 2 * 1024 * 1024;
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| 21 | int retry_count = 10;
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| 22 | bool dropped;
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| 23 | void *alloc;
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| 24 |
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| 25 | ksft_print_header();
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| 26 | ksft_set_plan(1);
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| 27 |
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| 28 | alloc = mmap(0, alloc_size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_DROPPABLE, -1, 0);
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| 29 | if (alloc == MAP_FAILED) {
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| 30 | if ((errno == EOPNOTSUPP) || (errno == EINVAL)) {
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| 31 | ksft_test_result_skip("MAP_DROPPABLE not supported\n");
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| 32 | exit(KSFT_SKIP);
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| 33 | }
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| 34 | ksft_test_result_fail("mmap error: %s\n", strerror(errno));
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| 35 | exit(KSFT_FAIL);
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| 36 | }
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| 37 | memset(alloc, 'A', alloc_size);
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| 38 |
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| 39 | while (retry_count--) {
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| 40 | if (madvise(alloc, alloc_size, MADV_PAGEOUT)) {
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| 41 | if (errno == EINVAL) {
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| 42 | ksft_test_result_skip("madvise(MADV_PAGEOUT) not supported\n");
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| 43 | exit(KSFT_SKIP);
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| 44 | }
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| 45 | ksft_test_result_fail("madvise(MADV_PAGEOUT) error: %s\n", strerror(errno));
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| 46 | exit(KSFT_FAIL);
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| 47 | }
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| 48 |
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| 49 | dropped = memchr(alloc, 'A', alloc_size) == NULL;
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| 50 |
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| 51 | |
| 52 | * Speculative reference can temporarily prevent some
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| 53 | * pages from getting dropped. So sleep and retry.
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| 54 | *
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| 55 | * If a page is not droppable for 10s, something
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| 56 | * is seriously messed up and we want to fail.
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| 57 |
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| 58 | if (dropped)
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| 59 | break;
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| 60 | sleep(1);
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| 61 | }
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| 62 |
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| 63 | ksft_test_result(dropped, "madvise(MADV_PAGEOUT) behavior\n");
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| 64 |
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| 65 | ksft_finished();
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| 66 | }
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