I checked the Linux headers and each kernel defines NR_FILE_PAGES as a member of the node_stat_item enumeration in include/linux/mmzone.h. I'm running on MX-17, which is derived from Debian Stable, and the headers are in:
/usr/src/linux-headers-4.14.0-3-common (using 4.14.0-3 as my current kernel). So, the kernel include files appear to be correct. As a point of reference, I still have ZFS 0.7.6 running on my primary server and the older ZFS doesn't check for NR_FILE_PAGES at all in its configure scripts. That's new behavior that's been introduced later and is now in 0.7.12. (I saw the added code while grepping for NR_FILE_PAGES). Seems like that logic is the place to look for this bug. Please LMK if I can help run experiments or try solutions. I have the broken ZFS 0.7.12 on a VM, also running MX-17, that I use to test major upgrades before putting them on my main machine. Thanks, Ben
