FYI, we noticed the below changes on git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm.git pmem-api commit 163f9409a57082aed03fbeeb321fbf18bdaf5f42 ("arch: introduce memremap(), replace ioremap_cache()") +------------------------------------------+------------+------------+ | | dc5d38e432 | 163f9409a5 | +------------------------------------------+------------+------------+ | boot_successes | 18 | 0 | | boot_failures | 3 | 23 | | BUG:kernel_test_oversize | 1 | | | BUG:kernel_test_crashed | 2 | | | WARNING:at_kernel/memremap.c:#memremap() | 0 | 23 | | backtrace:acpi_load_tables | 0 | 23 | | backtrace:acpi_early_init | 0 | 23 | +------------------------------------------+------------+------------+ [ 0.005013] ACPI: Core revision 20150619 [ 0.006041] memremap: acpi_os_map_iomem [ 0.007005] ------------[ cut here ]------------ [ 0.008009] WARNING: CPU: 0 PID: 0 at kernel/memremap.c:31 memremap+0xbf/0x130() [ 0.009005] memremap attempted on unknown/mixed range 0x0000000013fe0000 size: 4096 [ 0.010004] Modules linked in: [ 0.012007] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.2.0-rc3-00007-g163f940 #4 [ 0.013005] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 0.014006] ffffffff81b80890 ffffffff81c9fd78 ffffffff8189d35e 0000000000000001 [ 0.017004] ffffffff81c9fdc8 ffffffff81c9fdb8 ffffffff8107349a 0000000000000001 [ 0.021005] 0000000000001000 0000000000000001 00000000ffffffff 0000000013fe0000 [ 0.024004] Call Trace: [ 0.025010] [<ffffffff8189d35e>] dump_stack+0x4c/0x65 [ 0.026009] [<ffffffff8107349a>] warn_slowpath_common+0x8a/0xc0 [ 0.027007] [<ffffffff81073516>] warn_slowpath_fmt+0x46/0x50 [ 0.028010] [<ffffffff81893da3>] ? acpi_os_map_iomem+0x10f/0x168 [ 0.030009] [<ffffffff811637cf>] memremap+0xbf/0x130 [ 0.031008] [<ffffffff81893da3>] acpi_os_map_iomem+0x10f/0x168 [ 0.032008] [<ffffffff81893e0a>] acpi_os_map_memory+0xe/0x10 [ 0.033008] [<ffffffff814b28f9>] acpi_tb_acquire_table+0x3e/0x6c [ 0.034008] [<ffffffff814b2a11>] acpi_tb_validate_table+0x4b/0x85 [ 0.035008] [<ffffffff81eab99e>] acpi_load_tables+0x75/0x206 [ 0.036007] [<ffffffff81eaa7fd>] acpi_early_init+0x73/0xd2 [ 0.037008] [<ffffffff81e5ef00>] start_kernel+0x3c6/0x46d [ 0.038008] [<ffffffff81e5e120>] ? early_idt_handler_array+0x120/0x120 [ 0.039008] [<ffffffff81e5e4d7>] x86_64_start_reservations+0x2a/0x2c [ 0.040007] [<ffffffff81e5e60f>] x86_64_start_kernel+0x136/0x145 [ 0.041011] ---[ end trace 9f242918c164e21c ]--- [ 0.042008] ACPI Exception: AE_NO_ACPI_TABLES, While loading namespace from ACPI tables (20150619/tbxfload-80) Thanks, Ying Huang