[Linux-ia64] mmap failure

Hi all,
    it looks like mmap fails when calling mmap as:

    mmap(0x30000066910000,
                16384,
            PROT_READ | PROT_WRITE,  
          MAP_FIXED,MAP_PRIVATE,
       fd,0x30000066910000);

Other addresses are ok. It fails with EINVAL.
Is 0x30000... reserved for the kernel ?
R.