Hi Dan, How do you test these patches? Do you have any instructions? I see for example that check_hotplug_memory_range() still enforces memory_block_size_bytes() alignment. Also, after removing check_hotplug_memory_range(), I tried to online 16M aligned DAX memory, and got the following panic: # echo online > /sys/devices/system/memory/memory7/state [ 202.193132] WARNING: CPU: 2 PID: 351 at drivers/base/memory.c:207 memory_block_action+0x110/0x178 [ 202.193391] Modules linked in: [ 202.193698] CPU: 2 PID: 351 Comm: sh Not tainted 5.1.0-rc7_pt_devdax-00038-g865af4385544-dirty #9 [ 202.193909] Hardware name: linux,dummy-virt (DT) [ 202.194122] pstate: 60000005 (nZCv daif -PAN -UAO) [ 202.194243] pc : memory_block_action+0x110/0x178 [ 202.194404] lr : memory_block_action+0x90/0x178 [ 202.194506] sp : ffff000016763ca0 [ 202.194592] x29: ffff000016763ca0 x28: ffff80016fd29b80 [ 202.194724] x27: 0000000000000000 x26: 0000000000000000 [ 202.194838] x25: ffff000015546000 x24: 00000000001c0000 [ 202.194949] x23: 0000000000000000 x22: 0000000000040000 [ 202.195058] x21: 00000000001c0000 x20: 0000000000000008 [ 202.195168] x19: 0000000000000007 x18: 0000000000000000 [ 202.195281] x17: 0000000000000000 x16: 0000000000000000 [ 202.195393] x15: 0000000000000000 x14: 0000000000000000 [ 202.195505] x13: 0000000000000000 x12: 0000000000000000 [ 202.195614] x11: 0000000000000000 x10: 0000000000000000 [ 202.195744] x9 : 0000000000000000 x8 : 0000000180000000 [ 202.195858] x7 : 0000000000000018 x6 : ffff000015541930 [ 202.195966] x5 : ffff000015541930 x4 : 0000000000000001 [ 202.196074] x3 : 0000000000000001 x2 : 0000000000000000 [ 202.196185] x1 : 0000000000000070 x0 : 0000000000000000 [ 202.196366] Call trace: [ 202.196455] memory_block_action+0x110/0x178 [ 202.196589] memory_subsys_online+0x3c/0x80 [ 202.196681] device_online+0x6c/0x90 [ 202.196761] state_store+0x84/0x100 [ 202.196841] dev_attr_store+0x18/0x28 [ 202.196927] sysfs_kf_write+0x40/0x58 [ 202.197010] kernfs_fop_write+0xcc/0x1d8 [ 202.197099] __vfs_write+0x18/0x40 [ 202.197187] vfs_write+0xa4/0x1b0 [ 202.197295] ksys_write+0x64/0xd8 [ 202.197430] __arm64_sys_write+0x18/0x20 [ 202.197521] el0_svc_common.constprop.0+0x7c/0xe8 [ 202.197621] el0_svc_handler+0x28/0x78 [ 202.197706] el0_svc+0x8/0xc [ 202.197828] ---[ end trace 57719823dda6d21e ]--- Thank you, Pasha
