Confusion about __do_fault and MM_ANONPAGES

[Joel Fernandes]

Hi,

I have some confusion about when is anon=1 when __do_fault is called.

__do_fault seems to be called only when the page fault is of a linear
or a non-linear mapping. My understanding is neither of these can be
anonymous, so I am confused about the below code fragment:

In which case is anon=1 when memory.c::__do_fault is called?
In __do_fault, you'll see something like...
        if (anon) {
            inc_mm_counter_fast(mm, MM_ANONPAGES);
            page_add_new_anon_rmap(page, vma, address);
        } else {


Thanks!
Joel