tracing mmap'ed IO with dtrace

[Alexey Egorov]

Hello,

I'm trying to use dtrace to trace filesystem IO, and it works great with ordinary read-write syscalls.
However, it doesn't catch mmap'ed IO. I understand that it is not possible to catch all memory accesses to mmap'ed region, but is it possible to catch page faults that is caused by such accesses?
dtrace manual says that there is vminfo::fspgin/fspgout probes; but it's not available on FreeBSD. Is it possible to use some of fbt probes here?

Thanks.