The following panic hits seemingly at random, but persistent (once a week on average): Fatal trap 12: page fault while in vm86 mode fault virtual address = 0x6400 fault code = user read, page not present instruction pointer = 0x200:0x4400 stack pointer = 0x0:0xddb50ff8 frame pointer = 0x0:0x57 code segment = base 0xc01cc039, limit 0x99830, type 0x18 = DPL 0, pres 1, def32 0, gran 0 processor eflags = interrupt enabled, resume, vm86, IOPL = 0 current process = 3824 (XFree86) interrupt mask = none trap number = 12 panic: page fault syncing disks... 36 9 5 3 done Uptime: 23m28s Terminate ACPI The machine runs 4.9-stable from March 4th. It has a dual NVidia card with two monitors at 1024x768 resolutions -- perhaps, some resource shortage in NVidia's driver? The code segment seems to point to shmat(), according to the sorted nm output fragment below (crash address inserted): [...] c01bfd08 t shm_delete_mapping c01bfd8c T shmdt c01bfe00 T shmat --> c01cc039 -- the code segment base from the panic above c01cc0e4 T sokqfilter c01cc15c t filt_sordetach c01cc1b4 t filt_soread c01cc214 t filt_sowdetach [...] Any comments? Thanks! -mi