Greeting's Today's next kernel fail to boot on powerpc kernel : 4.18.0-rc4-next-20180711 Boot is completely broken, I see Oops message and the fault instruction maps to below code path # gdb -batch vmlinux -ex 'list *(0xc000000000d175e8)' 0xc000000000d175e8 is in __free_pages_bootmem (mm/page_alloc.c:1270). 1265 set_page_count(p, 0); 1266 } 1267 __ClearPageReserved(p); 1268 set_page_count(p, 0); 1269 1270 page_zone(page)->managed_pages += nr_pages; 1271 set_page_refcounted(page); 1272 __free_pages(page, order); 1273 } 1274 and on few machines I see below trace logs: ------------------------------------ vmemmap_populate: Unable to cre[ 0.000000] vmemmap_populate: Unable to create vmemmap mapping: -1 sparse_mem_maps_populate_node: sparsemem memory map backing failed some memory will not be available vmemmap_populate: Unable to create vmemmap mapping: -1 sparse_mem_maps_populate_node: sparsemem memory map backing failed some memory will not be available vmemmap_populate: Unable to create vmemmap mapping: -1 sparse_mem_maps_populate_node: sparsemem memory map backing failed some memory will not be available vmemmap_populate: Unable to create vmemmap mapping: -1 sparse_mem_maps_populate_node: sparsemem memory map b[ 0.000000] percpu: Embedded 4 pages/cpu @(____ptrval____) s168728 r0 d93416 u262144 Built 2 zonelists, mobility grouping on. Total pages: 167772 Policy zone: DMA Kernel command line: rw root=/dev/mapper/rhel_ci--s822l1--lp10-root BUG: Bad page state in process swapper pfn:01e01 page:f000000000078040 count:0 mapcount:1 mapping:0000000000000000 index:0x0 flags: 0x0() raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 page dumped because: nonzero mapcount Modules linked in: CPU: 3 PID: 0 Comm: swapper Not tainted 4.18.0-rc4-next-20180711-autotest-autotest #1 Call Trace: [c00000000112fd20] [c0000000009a920c] dump_stack+0xb0/0xf4 (unreliable) [c00000000112fd60] [c0000000002859ac] bad_page+0x11c/0x190 [c00000000112fdf0] [c0000000002873d0] __free_pages_ok+0x3f0/0x400 [c00000000112fe60] [c000000000d1e45c] free_all_bootmem+0x184/0x218 [c00000000112fee0] [c000000000cf33fc] mem_init+0x40/0x60 [c00000000112ff00] [c000000000ce402c] start_kernel+0x2a4/0x5dc [c00000000112ff90] [c00000000000ac7c] start_here_common+0x1c/0x520 Disabling lock debugging due to kernel taint BUG: Bad page state in process swapper pfn:01e02 Related commit could be one of below ? I see lots of patches related to mm and could not bisect 5479976fda7d3ab23ba0a4eb4d60b296eb88b866 mm: page_alloc: restore memblock_next_valid_pfn() on arm/arm64 41619b27b5696e7e5ef76d9c692dd7342c1ad7eb mm-drop-vm_bug_on-from-__get_free_pages-fix 531bbe6bd2721f4b66cdb0f5cf5ac14612fa1419 mm: drop VM_BUG_ON from __get_free_pages 479350dd1a35f8bfb2534697e5ca68ee8a6e8dea mm, page_alloc: actually ignore mempolicies for high priority allocations 088018f6fe571444caaeb16e84c9f24f22dfc8b0 mm: skip invalid pages block at a time in zero_resv_unresv() -- Regard's Abdul Haleem IBM Linux Technology Centre