Attachment 150465 Details for Bug 195882 – example code

example code

testvm.c (text/plain), 1.99 KB, created by Ivan Rozhuk on 2014-12-11 08:31:53 UTC

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Creator: Ivan Rozhuk

Created: 2014-12-11 08:31:53 UTC

Size: 1.99 KB

patch

obsolete

>
>/* rtorrent + FreeBSD pagedaemon prombel simulator
> * 2014 Rozhuk Ivan <rozhuk.im@gmail.com>
> *
> * compile-command: "clang -Wall -O2 -o testvm testvm.c"
> */
>
>
>#include <sys/cdefs.h>
>#include <sys/types.h>
>#include <sys/stat.h> // chmod, fchmod, umask
>#include <sys/uio.h> /* readv, preadv, writev, pwritev */
>#include <sys/mman.h> /* mmap, munmap */
>
>#include <errno.h>
>#include <fcntl.h> /* open, fcntl */
>#include <stdio.h>  /* snprintf, fprintf */
>#include <string.h> /* bcopy, bzero, memcpy, memmove, memset, strnlen, strerror... */
>#include <unistd.h> /* close, write, sysconf */
>#include <stdlib.h> /* malloc, exit */
>
>#define LOG_ERR(error, descr)							\
>	fprintf(stdout, "fn: %s, line: %i, error: %i - %s, %s\n",		\
>		__FUNCTION__, __LINE__, error, strerror(error), descr);
>
>int
>main(int argc, char *argv[]) {
>	int error = 0, fd;
>	const char *file_name = (const char *)"/testvn.tmp";
>	off_t mb = (1024 * 1024); /* 1 megabyte. */
>	off_t file_size = (4 * 1024 * mb); /* Set to x2 RAM size. */
>	off_t write_size = (32 * mb); /* Write block size. */
>	off_t i, j, page_size;
>	uint8_t *mem;
>
>	fd = open(file_name, (O_RDWR | O_CREAT/* | O_DIRECT*/), 0600);
>	if (-1 == fd) {
>		error = errno;
>		LOG_ERR(error, "open()");
>		goto err_out;
>	}
>	if (0 != flock(fd, LOCK_EX)) {
>		error = errno;
>		LOG_ERR(error, "flock()");
>		goto err_out;
>	}
>	if (0 != ftruncate(fd, file_size)) {
>		error = errno;
>		LOG_ERR(error, "ftruncate()");
>		goto err_out;
>	}
>
>	page_size = sysconf(_SC_PAGE_SIZE);
>	for (i = 0; i < (file_size / write_size); i ++) {
>		mem = mmap(NULL, write_size, (PROT_READ | PROT_WRITE),
>		    (MAP_SHARED | MAP_NOCORE), fd, (i * write_size));
>		if (MAP_FAILED == mem) {
>			error = errno;
>			LOG_ERR(error, "mmap()");
>			goto err_out;
>		}
>		for (j = 0; j < (write_size / page_size); j ++) {
>			mem[(j * page_size)] = 1;
>		}
>		//msync(mem, file_size, MS_SYNC);
>		//posix_madvise(mem, file_size, MADV_FREE);
>		munmap(mem, file_size);
>	}
>
>err_out:
>	close(fd);
>	//unlink(file_name); /* Delete file to free all mem. */
>
>	return (error);
>}

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Attachments on bug 195882: 150465