From: Huang Ying <ying.huang@xxxxxxxxx> [ Upstream commit ccae0f36d500aef727f98acd8d0601e6b262a513 ] Commit: cc9aec03e58f ("x86/numa_emulation: Introduce uniform split capability") uses "-1" as the starting node ID, which causes the strange kernel log as follows, when "numa=fake=32G" is added to the kernel command line: Faking node -1 at [mem 0x0000000000000000-0x0000000893ffffff] (35136MB) Faking node 0 at [mem 0x0000001840000000-0x000000203fffffff] (32768MB) Faking node 1 at [mem 0x0000000894000000-0x000000183fffffff] (64192MB) Faking node 2 at [mem 0x0000002040000000-0x000000283fffffff] (32768MB) Faking node 3 at [mem 0x0000002840000000-0x000000303fffffff] (32768MB) And finally the kernel crashes: BUG: Bad page state in process swapper pfn:00011 page:(____ptrval____) refcount:0 mapcount:1 mapping:(____ptrval____) index:0x55cd7e44b270 pfn:0x11 failed to read mapping contents, not a valid kernel address? flags: 0x5(locked|uptodate) raw: 0000000000000005 000055cd7e44af30 000055cd7e44af50 0000000100000006 raw: 000055cd7e44b270 000055cd7e44b290 0000000000000000 000055cd7e44b510 page dumped because: page still charged to cgroup page->mem_cgroup:000055cd7e44b510 Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 5.9.0-rc2 #1 Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019 Call Trace: dump_stack+0x57/0x80 bad_page.cold+0x63/0x94 __free_pages_ok+0x33f/0x360 memblock_free_all+0x127/0x195 mem_init+0x23/0x1f5 start_kernel+0x219/0x4f5 secondary_startup_64+0xb6/0xc0 Fix this bug via using 0 as the starting node ID. This restores the original behavior before cc9aec03e58f. [ mingo: Massaged the changelog. ] Fixes: cc9aec03e58f ("x86/numa_emulation: Introduce uniform split capability") Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Link: https://lore.kernel.org/r/20200904061047.612950-1-ying.huang@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/x86/mm/numa_emulation.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/numa_emulation.c b/arch/x86/mm/numa_emulation.c index c5174b4e318b4..683cd12f47938 100644 --- a/arch/x86/mm/numa_emulation.c +++ b/arch/x86/mm/numa_emulation.c @@ -321,7 +321,7 @@ static int __init split_nodes_size_interleave(struct numa_meminfo *ei, u64 addr, u64 max_addr, u64 size) { return split_nodes_size_interleave_uniform(ei, pi, addr, max_addr, size, - 0, NULL, NUMA_NO_NODE); + 0, NULL, 0); } static int __init setup_emu2phys_nid(int *dfl_phys_nid) -- 2.25.1