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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2024 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/
#include <assert.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <sys/mman.h>
#include <linux/mman.h>
#include "kselftest.h"
int main(int argc, char *argv[])
{
const size_t alloc_size = 2 * 1024 * 1024;
int retry_count = 10;
bool dropped;
void *alloc;
ksft_print_header();
ksft_set_plan(1);
alloc = mmap(0, alloc_size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_DROPPABLE, -1, 0);
if (alloc == MAP_FAILED) {
if ((errno == EOPNOTSUPP) || (errno == EINVAL)) {
ksft_test_result_skip("MAP_DROPPABLE not supported\n");
exit(KSFT_SKIP);
}
ksft_test_result_fail("mmap error: %s\n", strerror(errno));
exit(KSFT_FAIL);
}
memset(alloc, 'A', alloc_size);
while (retry_count--) {
if (madvise(alloc, alloc_size, MADV_PAGEOUT)) {
if (errno == EINVAL) {
ksft_test_result_skip("madvise(MADV_PAGEOUT) not supported\n");
exit(KSFT_SKIP);
}
ksft_test_result_fail("madvise(MADV_PAGEOUT) error: %s\n", strerror(errno));
exit(KSFT_FAIL);
}
dropped = memchr(alloc, 'A', alloc_size) == NULL;
/*
* Speculative reference can temporarily prevent some
* pages from getting dropped. So sleep and retry.
*
* If a page is not droppable for 10s, something
* is seriously messed up and we want to fail.
*/
if (dropped)
break;
sleep(1);
}
ksft_test_result(dropped, "madvise(MADV_PAGEOUT) behavior\n");
ksft_finished();
}
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