ngx_read_ahead    578 src/os/unix/ngx_files.c ngx_read_ahead(ngx_fd_t fd, size_t n)
ngx_read_ahead    308 src/os/unix/ngx_files.h #define ngx_read_ahead(fd, n)    fcntl(fd, F_READAHEAD, (int) n)
ngx_read_ahead    320 src/os/unix/ngx_files.h #define ngx_read_ahead(fd, n)    0