On several systems I am seeing a boot panic if I use mmotm (stamp-2010-03-02-18-38). If I remove bootmem-avoid-dma32-zone-by-default.patch then no panic is seen. I find that: * 2.6.33 boots fine. * 2.6.33 + mmotm w/o bootmem-avoid-dma32-zone-by-default.patch: boots fine. * 2.6.33 + mmotm (including bootmem-avoid-dma32-zone-by-default.patch): panics. Note: I had to enable earlyprintk to see the panic. Without earlyprintk no console output was seen. The system appeared to hang after the loader. Here's the panic seen with earlyprintk using 2.6.33 + mmotm: Starting up ... [ 0.000000] Initializing cgroup subsys cpuset [ 0.000000] Initializing cgroup subsys cpu [ 0.000000] Linux version 2.6.33-mm1+ (gthelen@xxxxxxxxxxxxxxxxxxxxxxxxx) (gcc version 4.2.4 (Ubuntu 4.2.4-1ubuntu4)) #1 SMP Thu Mar 4 12:03:29 PST 2010 [ 0.000000] Command line: root=UUID=a77f406a-7cc7-4f49-9cc2-818b2b4159ae ro console=tty0 console=ttyS0,115200n8 earlyprintk=serial,ttyS0,9600 [ 0.000000] BIOS-provided physical RAM map: [ 0.000000] BIOS-e820: 0000000000000000 - 000000000009fc00 (usable) [ 0.000000] BIOS-e820: 000000000009fc00 - 00000000000a0000 (reserved) [ 0.000000] BIOS-e820: 00000000000e8000 - 0000000000100000 (reserved) [ 0.000000] BIOS-e820: 0000000000100000 - 000000000fff0000 (usable) [ 0.000000] BIOS-e820: 000000000fff0000 - 0000000010000000 (ACPI data) [ 0.000000] BIOS-e820: 00000000fffbd000 - 0000000100000000 (reserved) [ 0.000000] bootconsole [earlyser0] enabled [ 0.000000] NX (Execute Disable) protection: active [ 0.000000] DMI 2.4 present. [ 0.000000] No AGP bridge found [ 0.000000] last_pfn = 0xfff0 max_arch_pfn = 0x400000000 [ 0.000000] PAT not supported by CPU. [ 0.000000] CPU MTRRs all blank - virtualized system. [ 0.000000] Scanning 1 areas for low memory corruption [ 0.000000] modified physical RAM map: [ 0.000000] modified: 0000000000000000 - 0000000000010000 (reserved) [ 0.000000] modified: 0000000000010000 - 000000000009fc00 (usable) [ 0.000000] modified: 000000000009fc00 - 00000000000a0000 (reserved) [ 0.000000] modified: 00000000000e8000 - 0000000000100000 (reserved) [ 0.000000] modified: 0000000000100000 - 000000000fff0000 (usable) [ 0.000000] modified: 000000000fff0000 - 0000000010000000 (ACPI data) [ 0.000000] modified: 00000000fffbd000 - 0000000100000000 (reserved) [ 0.000000] init_memory_mapping: 0000000000000000-000000000fff0000 [ 0.000000] RAMDISK: 0fd9d000 - 0ffdf539 [ 0.000000] ACPI: RSDP 00000000000fb450 00014 (v00 QEMU ) [ 0.000000] ACPI: RSDT 000000000fff0000 00030 (v01 QEMU QEMURSDT 00000001 QEMU 00000001) [ 0.000000] ACPI: FACP 000000000fff0030 00074 (v01 QEMU QEMUFACP 00000001 QEMU 00000001) [ 0.000000] ACPI: DSDT 000000000fff0100 0089D (v01 BXPC BXDSDT 00000001 INTL 20061109) [ 0.000000] ACPI: FACS 000000000fff00c0 00040 [ 0.000000] ACPI: APIC 000000000fff09d8 00068 (v01 QEMU QEMUAPIC 00000001 QEMU 00000001) [ 0.000000] ACPI: SSDT 000000000fff099d 00037 (v01 QEMU QEMUSSDT 00000001 QEMU 00000001) [ 0.000000] No NUMA configuration found [ 0.000000] Faking a node at 0000000000000000-000000000fff0000 [ 0.000000] Initmem setup node 0 0000000000000000-000000000fff0000 [ 0.000000] NODE_DATA [0000000001c4e040 - 0000000001c5303f] [ 0.000000] BUG: unable to handle kernel NULL pointer dereference at (null) [ 0.000000] IP: [<ffffffff81b0f5f7>] memory_present+0x9a/0xbf [ 0.000000] PGD 0 [ 0.000000] Oops: 0000 [#1] SMP [ 0.000000] last sysfs file: [ 0.000000] CPU 0 [ 0.000000] Modules linked in: [ 0.000000] [ 0.000000] Pid: 0, comm: swapper Not tainted 2.6.33-mm1+ #1 / [ 0.000000] RIP: 0010:[<ffffffff81b0f5f7>] [<ffffffff81b0f5f7>] memory_present+0x9a/0xbf [ 0.000000] RSP: 0000:ffffffff81a01e18 EFLAGS: 00010046 [ 0.000000] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 [ 0.000000] RDX: 0000000000000000 RSI: 0000000000000040 RDI: 0000000000000000 [ 0.000000] RBP: ffffffff81a01e58 R08: ffffffffffffffff R09: 0000000000000040 [ 0.000000] R10: ffff880001c4e040 R11: 0000000000004100 R12: 0000000000000000 [ 0.000000] R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000000 [ 0.000000] FS: 0000000000000000(0000) GS:ffffffff81adf000(0000) knlGS:0000000000000000 [ 0.000000] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.000000] CR2: 0000000000000000 CR3: 0000000001a08000 CR4: 00000000000000b0 [ 0.000000] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 0.000000] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 0.000000] Process swapper (pid: 0, threadinfo ffffffff81a00000, task ffffffff81a10020) [ 0.000000] Stack: [ 0.000000] 000000000fff0000 000000000000009f 0000000000000000 0000000000000000 [ 0.000000] <0> 0000000000000040 ffffffff81a01ef8 0000000000000000 0000000000000000 [ 0.000000] <0> ffffffff81a01e78 ffffffff81b0dd0e ffffffff81a01e88 000000000fff0000 [ 0.000000] Call Trace: [ 0.000000] [<ffffffff81b0dd0e>] sparse_memory_present_with_active_regions+0x31/0x47 [ 0.000000] [<ffffffff81b0688a>] paging_init+0x3f/0x5b [ 0.000000] [<ffffffff81af81a7>] setup_arch+0x964/0xa03 [ 0.000000] [<ffffffff8103014a>] ? need_resched+0x1e/0x28 [ 0.000000] [<ffffffff8103015d>] ? should_resched+0x9/0x2a [ 0.000000] [<ffffffff8152de24>] ? _cond_resched+0x9/0x1d [ 0.000000] [<ffffffff81af4a34>] start_kernel+0x9f/0x382 [ 0.000000] [<ffffffff81af4299>] x86_64_start_reservations+0xa9/0xad [ 0.000000] [<ffffffff81af4383>] x86_64_start_kernel+0xe6/0xed [ 0.000000] Code: c7 00 56 c2 81 e8 a0 f9 a1 ff 48 83 3c dd 00 16 c2 81 00 75 08 4c 89 2c dd 00 16 c2 81 fe 05 11 60 11 00 4c 89 ff e8 85 3b 5c ff <48> 83 38 00 75 03 4c 89 30 49 81 c4 00 80 00 00 4c 3b 65 c8 72 [ 0.000000] RIP [<ffffffff81b0f5f7>] memory_present+0x9a/0xbf [ 0.000000] RSP <ffffffff81a01e18> [ 0.000000] CR2: 0000000000000000 [ 0.000000] ---[ end trace 4eaa2a86a8e2da22 ]--- [ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task! [ 0.000000] Pid: 0, comm: swapper Tainted: G D 2.6.33-mm1+ #1 [ 0.000000] Call Trace: [ 0.000000] [<ffffffff8103c78c>] panic+0x9e/0x113 [ 0.000000] [<ffffffff8103d3d6>] ? printk+0x67/0x69 [ 0.000000] [<ffffffff8105914e>] ? blocking_notifier_call_chain+0xf/0x11 [ 0.000000] [<ffffffff8103f8b4>] do_exit+0x78/0x70f [ 0.000000] [<ffffffff8103ca2f>] ? spin_unlock_irqrestore+0x9/0xb [ 0.000000] [<ffffffff8103dcde>] ? kmsg_dump+0x112/0x138 [ 0.000000] [<ffffffff81530061>] oops_end+0xb2/0xba [ 0.000000] [<ffffffff810258d3>] no_context+0x1f5/0x204 [ 0.000000] [<ffffffff81025b1b>] __bad_area_nosemaphore+0x17f/0x1a2 [ 0.000000] [<ffffffff81025bb4>] bad_area_nosemaphore+0xe/0x10 [ 0.000000] [<ffffffff81531e36>] do_page_fault+0x122/0x24c [ 0.000000] [<ffffffff8152f59f>] page_fault+0x1f/0x30 [ 0.000000] [<ffffffff81b0f5f7>] ? memory_present+0x9a/0xbf [ 0.000000] [<ffffffff81b0f5f7>] ? memory_present+0x9a/0xbf [ 0.000000] [<ffffffff81b0dd0e>] sparse_memory_present_with_active_regions+0x31/0x47 [ 0.000000] [<ffffffff81b0688a>] paging_init+0x3f/0x5b [ 0.000000] [<ffffffff81af81a7>] setup_arch+0x964/0xa03 [ 0.000000] [<ffffffff8103014a>] ? need_resched+0x1e/0x28 [ 0.000000] [<ffffffff8103015d>] ? should_resched+0x9/0x2a [ 0.000000] [<ffffffff8152de24>] ? _cond_resched+0x9/0x1d [ 0.000000] [<ffffffff81af4a34>] start_kernel+0x9f/0x382 [ 0.000000] [<ffffffff81af4299>] x86_64_start_reservations+0xa9/0xad [ 0.000000] [<ffffffff81af4383>] x86_64_start_kernel+0xe6/0xed The kernel was built with 'make mrproper && make defconfig && make ARCH=x86_64 CONFIG=smp -j 6'. This panic is seen on every attempt, so I can provide more diagnostics. -- Greg -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>