On Thu, Jan 07, 2021 at 12:32:09PM -0800, Linus Torvalds wrote:

I think Andrea is blinded by his own love for UFFDIO: when I do a
debian codesearch for UFFDIO_WRITEPROTECT, all it finds is the kernel
and strace (and the qemu copies of the kernel headers).

For the record, I feel obliged to reiterate I'm thinking purely in
clear_refs terms here.

It'd be great if we can only focus on clear_refs_write and nothing
else.

Like I said earlier, whatever way clear_refs/softdirty copes with
do_wp_page, uffd-wp can do the identical thing so, uffd-wp is
effectively irrelevant in this whole discussion. Clear-refs/softdirty
predates uffd-wp by several years too.

Thanks,
Andrea