During the last weeks I identified 64 patches for ZFS which are in 8-stable but not in 7‑stable. For 56 of them I had a deeper look and most of them are commited now to 7‑stable. The ones of those 56 which I did not commit are not applicable to 7‑stable (infrastructure differences between 8 and 7).
Unfortunately this did not solve the stability problems I have on a 7‑stable system.
I also committed a diff reduction (between 8‑stable and 7‑stable) patch which also fixed some not so harmless mismerges (mem-leak and initializing the same mutex twice at different places). No idea yet if it helps in my case.
I also want to merge the new arc reclaim logic from head to 8‑stable and 7‑stable. Maybe I can do this tomorrow.