On 11/01/2009 07:07 PM, akpm at linux-foundation.org wrote: > The mm-of-the-moment snapshot 2009-11-01-10-01 has been uploaded to Hi, kdump loading crashes: BUG: unable to handle kernel paging request at ffff8800010a7000 IP: [<ffffffff8101cd8b>] machine_kexec_prepare+0x16b/0x13e0 PGD 1806063 PUD 180a063 PMD 10001e1 Oops: 0003 [#1] SMP last sysfs file: /sys/firmware/memmap/10/type CPU 1 Modules linked in: fuse ath5k ath Pid: 3250, comm: kexec Tainted: G W 2.6.32-rc5-mm1_64 #869 To Be Filled By O.E.M. RIP: 0010:[<ffffffff8101cd8b>] [<ffffffff8101cd8b>] machine_kexec_prepare+0x16b/0x13e0 RSP: 0018:ffff8801c95d1e88 EFLAGS: 00010206 RAX: 00000000000001e3 RBX: ffff8801ca2aac00 RCX: 0000000040000000 RDX: 0000000000200000 RSI: ffff8800010a7000 RDI: ffff8800010a7000 RBP: ffff8801c95d1ee8 R08: 00000000000010a7 R09: 00000000010a7fff R10: 0000000000000fff R11: 0000000004ffffff R12: 0000000000000000 R13: ffff8800010a6000 R14: 0000008000000000 R15: ffff880000000000 FS: 00007f4f97b4c6f0(0000) GS:ffff880028280000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8800010a7000 CR3: 00000001c8cf2000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process kexec (pid: 3250, threadinfo ffff8801c95d0000, task ffff8801ca116700) Stack: ffff8801c95d1ee8 ffff8800010a6000 ffff8800010a4000 ffff8800010a4000 <0> 0000000000000000 00000001cc000000 ffff8801c95d1ee8 0000000000000006 <0> ffff8801ca2aac00 0000000000000000 0000000000000000 000000000146eae0 Call Trace: [<ffffffff8106d32c>] sys_kexec_load+0xec/0x5e0 [<ffffffff814365b5>] ? do_page_fault+0x185/0x350 [<ffffffff81002e6b>] system_call_fastpath+0x16/0x1b Code: 00 40 48 c1 e6 0c 4c 01 fe 48 39 ca 73 21 48 89 f7 0f 1f 80 00 00 00 00 48 89 d0 48 81 c2 00 00 20 00 48 0d e3 01 00 00 48 39 d1 <48> ab 77 e9 48 89 f7 49 81 c4 00 00 00 40 e8 e2 93 00 00 4c 89 RIP [<ffffffff8101cd8b>] machine_kexec_prepare+0x16b/0x13e0 RSP <ffff8801c95d1e88> CR2: ffff8800010a7000 ---[ end trace 4eaa2a86a8e2da24 ]--- ffff8800010a7000 should be OK, as crashkernel=64M at 16M was passed to the kernel. It's here: static void init_level2_page(pmd_t *level2p, unsigned long addr) { unsigned long end_addr; addr &= PAGE_MASK; end_addr = addr + PUD_SIZE; while (addr < end_addr) { here -> set_pmd(level2p++, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC)); addr += PMD_SIZE; } } Corresponding -fverbose-asm with -g: .loc 1 65 0 addq $2097152, %rdx #, addr .LVL31: .LBB416: .loc 5 77 0 orq $483, %rax #, tmp140 .LBE416: .loc 1 63 0 cmpq %rdx, %rcx # addr, end_addr .LBB417: .loc 5 77 0 stosq .LVL32: .LBE417: .loc 1 63 0 ja .L26 #,