PSI_DECL(ssize_t readv, [(int fd, struct iovec *iov, int iovcnt)])
PSI_DECL(ssize_t writev, [(int fd, struct iovec *iov, int iovcnt)])
PSI_DECL(ssize_t readv, [(int fd, struct iovec *iov, int iovcnt)])
PSI_DECL(ssize_t writev, [(int fd, struct iovec *iov, int iovcnt)])