vfs.add_to_page_cache not working anymore?

[Daire Byrne]

I have recently updated my kernel (v6.3) and with systemtap version (v4.8),
an old systemtap script I was using has stopped working.

It looks like I was counting pages added via vfs.add_to_page_cache as a
means to work out file reads (over NFS) per pid.

But this function no longer seem to hit at all for me anymore:

stap -e 'probe vfs.add_to_page_cache { printf("Works.\n"); exit() }'

I am aware that v4.9 is the latest systemtap, but I have been struggling to
get it to compile with the new jupyter stuff (my python version is too old).

Anyway, any help or pointers for vfs.add_to_page_cache greatly appreciated.

Daire