Hi, Here are patches for kdump on ia64 to fix the follwing problems: - [PATCH 1/2] Fix kernel panic in kdump on INIT I encountered the kernel panic when I sent an INIT without configuring kdump kernel image. The cause of this problem seems that machine_kdump_on_init() uses printk() in INIT context. Replacing it with ia64_mca_printk() fixes this problem. The panic message is attached at the end of this mail. - [PATCH 2/2] Fix kernel hangup in kdump on INIT Even after fixing the kernel panic problem mentioned above, I encontered the kernel hangup problem when I sent an INIT without configuring kdump kernel image. The kdump_init_notifier() on monarch CPU stops its operation if the kdump kernel image is not configured. On the other hand, kdump_init_notifier() on non-monarch CPUs get into spin because they don't know the fact the monarch stops its operation. This is the cause of this problem. Thanks, Kenji Kaneshige machine_kdump_on_init(): kdump not configured Unable to handle kernel NULL pointer dereference (address 0000000000000020) INIT swapper 1[0]: Oops 11012296146944 [1] Modules linked in: sunrpc binfmt_misc dm_mirror dm_mod fan sg eepro100 container e100 mii button thermal processor usb_storage ehci_hcd ohci_hcd Pid: 0, CPU 1, comm: INIT swapper 1 psr : 0000121808022030 ifs : 8000000000000813 ip : [<a00000010006a3a1>] Not tainted ip is at try_to_wake_up+0x5c1/0x740 unat: 0000000000000000 pfs : 0000000000000813 rsc : 0000000000000003 rnat: 0000000000000000 bsps: 0000000000000000 pr : 000000000000a685 ldrs: 0000000000000000 ccv : 0000000000000000 fpsr: 0009804c0270033f csd : 0000000000000000 ssd : 0000000000000000 b0 : a00000010006a350 b6 : a000000100071540 b7 : e00000007fd08010 f6 : 1003e0000005b41d7540b f7 : 1003e00000000000005dc f8 : 1003e000000002aaaaaab f9 : 1003e0000005b41d77388 f10 : 1003e35a3e8b515f27bd8 f11 : 1003e000000000000000f r1 : a000000100bf9e20 r2 : 0000000000000000 r3 : a0000001009faa70 r8 : 0000003ba3d925e4 r9 : 0000003b9e207e0a r10 : e0000000010368d0 r11 : 0000003b9e207e0a r12 : e00000000115fa80 r13 : e000000001150000 r14 : 0000000000000400 r15 : 0000000000000400 r16 : e0000000010368c0 r17 : e000000001036ff8 r18 : e0000000010368c0 r19 : e00000007da10000 r20 : 0000000000000000 r21 : e000000001150000 r22 : e000000001036910 r23 : 0000000000000000 r24 : 0000000000000020 r25 : 0000000000000000 r26 : e000000001150040 r27 : e000000001150000 r28 : e000000001036fd8 r29 : a000000100a1a350 r30 : 0000000000000000 r31 : e000000001036880 Call Trace: [<a000000100013c20>] show_stack+0x40/0xa0 sp=e00000000115f650 bsp=e000000001151148 [<a0000001000148a0>] show_regs+0x840/0x880 sp=e00000000115f820 bsp=e0000000011510f0 [<a000000100036e80>] die+0x1a0/0x2a0 sp=e00000000115f820 bsp=e0000000011510a8 [<a000000100061610>] ia64_do_page_fault+0x8d0/0xa00 sp=e00000000115f820 bsp=e000000001151058 [<a00000010000b240>] ia64_leave_kernel+0x0/0x270 sp=e00000000115f8b0 bsp=e000000001151058 [<a00000010006a3a0>] try_to_wake_up+0x5c0/0x740 sp=e00000000115fa80 bsp=e000000001150fb8 [<a00000010006a550>] default_wake_function+0x30/0x60 sp=e00000000115fa90 bsp=e000000001150f88 [<a0000001000a9670>] autoremove_wake_function+0x30/0xa0 sp=e00000000115fa90 bsp=e000000001150f50 [<a0000001000641a0>] __wake_up_common+0x60/0x120 sp=e00000000115fa90 bsp=e000000001150f00 [<a000000100067fd0>] __wake_up+0x50/0x80 sp=e00000000115fa90 bsp=e000000001150ec0 [<a0000001000784b0>] wake_up_klogd+0x70/0xa0 sp=e00000000115fa90 bsp=e000000001150ea8 [<a000000100079940>] release_console_sem+0x4a0/0x4c0 sp=e00000000115fa90 bsp=e000000001150e60 [<a000000100078e40>] vprintk+0x7c0/0x940 sp=e00000000115fa90 bsp=e000000001150dd8 [<a000000100079050>] printk+0x90/0xc0 sp=e00000000115fb00 bsp=e000000001150d78 [<a00000010005f380>] machine_kdump_on_init+0x40/0xc0 sp=e00000000115fb50 bsp=e000000001150d60 [<a00000010005f650>] kdump_init_notifier+0x250/0x280 sp=e00000000115fb50 bsp=e000000001150d30 [<a000000100097c10>] notifier_call_chain+0x50/0xe0 sp=e00000000115fb50 bsp=e000000001150ce8 [<a000000100097ce0>] __atomic_notifier_call_chain+0x40/0x60 sp=e00000000115fb50 bsp=e000000001150ca8 [<a000000100097d40>] atomic_notifier_call_chain+0x40/0x60 sp=e00000000115fb50 bsp=e000000001150c78 [<a0000001000b2160>] notify_die+0x80/0xa0 sp=e00000000115fb50 bsp=e000000001150c30 [<a000000100049220>] ia64_init_handler+0x800/0x900 sp=e00000000115fb70 bsp=e000000001150bd8 [<a000000100049b40>] ia64_os_init_virtual_begin+0x40/0x140 sp=e00000000115fb80 bsp=e000000001150bd8