gistfile1.txt

#include <unistd.h>
#include <fcntl.h>
#include <stdint.h>

#define RWH_WRITE_LIFE_EXTREME  5
#define F_SET_FILE_RW_HINT      (F_LINUX_SPECIFIC_BASE + 14)
#define F_SET_RW_HINT           (F_LINUX_SPECIFIC_BASE + 12)
#define F_LINUX_SPECIFIC_BASE   1024


main()
{
	int fd1 = open("test1.tmp", O_RDWR|O_TRUNC|O_CREAT);
	int fd2 = open("test2.tmp", O_RDWR|O_TRUNC|O_CREAT);
	uint64_t h = RWH_WRITE_LIFE_EXTREME;
	char buf[1024*1024];

	if (fd1 < 0 || fd2 < 0) {
		perror("open");
		exit(1);
	}

	if (fcntl(fd1, F_SET_RW_HINT, &h)) {
		perror("fcntl1");
		exit(1);
	}
	if (fcntl(fd2, F_SET_RW_HINT, &h)) {
		perror("fcntl2");
		exit(1);
	}

	write(fd1, buf, 4096);
	write(fd2, buf, sizeof(buf)-4096);

	exit(0);
}