On Thu, 2016-05-05 at 07:54:09 UTC, Oliver O'Halloran wrote: > The mm zone mechanism was traditionally used by arch specific code to > partition memory into allocation zones. However there are several zones > that are managed by the mm subsystem rather than the architecture. Most > architectures set the max PFN of these special zones to zero, however on > powerpc we set them to ~0ul. This, in conjunction with a bug in > free_area_init_nodes() results in all of system memory being placed in > ZONE_DEVICE when enabled. Device memory cannot be used for regular kernel > memory allocations so this will cause a kernel panic at boot. This is breaking my freescale machine: Sorting __ex_table... Unable to handle kernel paging request for data at address 0xc000000101e28020 Faulting instruction address: 0xc0000000009ab698 cpu 0x0: Vector: 300 (Data Access) at [c000000000acbb30] pc: c0000000009ab698: .reserve_bootmem_region+0x64/0x8c lr: c0000000009883d0: .free_all_bootmem+0x70/0x200 sp: c000000000acbdb0 msr: 80021000 dar: c000000101e28020 dsisr: 800000 current = 0xc000000000a07640 paca = 0xc00000003fff5000 softe: 0 irq_happened: 0x01 pid = 0, comm = swapper Linux version 4.6.0-rc3-00160-gc09920947f23 (michael@ka1) (gcc version 5.3.0 (GCC) ) #5 SMP Tue May 10 09:44:11 AEST 2016 enter ? for help [link register ] c0000000009883d0 .free_all_bootmem+0x70/0x200 [c000000000acbdb0] c000000000988398 .free_all_bootmem+0x38/0x200 (unreliable) [c000000000acbe80] c00000000097b700 .mem_init+0x5c/0x7c [c000000000acbef0] c000000000971a0c .start_kernel+0x28c/0x4e4 [c000000000acbf90] c000000000000544 start_here_common+0x20/0x5c 0:mon> ? I can give you access some time if you need to debug it. cheers -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>