Linux buffer cache state

Following Faidon’s comment on an earlier post, I came across  this informative site concerning Linux’s buffer cache state. In a nutshell, the following code will release all the cached data of a specified file.

#define _XOPEN_SOURCE 600
#include <unistd.h>
#include <fcntl.h>
int main(int argc, char *argv[]) {
    int fd;
    fd = open(argv[1], O_RDONLY);
    fdatasync(fd);
    posix_fadvise(fd, 0,0,POSIX_FADV_DONTNEED);
    close(fd);
    return 0;
}

There are some useful samples and examples on the mentioned web page. posix_fadvise description here.

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