Hi, I am having problems while booting 2.6.12-rc2-mm1 on i386 with command line maxcpus=1. Without this commandline, system boots fine otherwise it hangs. Serial output is pasted below. If maxcpus=1 is given along with acpi=off then system boots fine. I am not sure where the problem is. 2.6.12-rc1-mm4 does not have this problem. Any idea what is going on? config file is attached with the mail. Thanks Vivek LILO boot: linux linux-up t base 2.6.5-sy 2.6.12-rc1-mm1 hzless Rachita-crash vivek sharyathi boot: vivek Loading vivek......................................... Linux version 2.6.12-rc2-mm1-1M (root@llm09.in.ibm.com) (gcc version 3.2.3 20030502 (Red Hat Linux 3.2.3-31)) #1 SMP PREEMPT Mon Apr 11 11:40:30 IST 2005 BIOS-provided physical RAM map: BIOS-e820: 0000000000000000 - 000000000009e000 (usable) BIOS-e820: 000000000009e000 - 00000000000a0000 (reserved) BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved) BIOS-e820: 0000000000100000 - 00000000efff6500 (usable) BIOS-e820: 00000000efff6500 - 00000000f0000000 (ACPI data) BIOS-e820: 00000000fffb0000 - 0000000100000000 (reserved) BIOS-e820: 0000000100000000 - 0000000200000000 (usable) user-defined physical RAM map: user: 0000000000000000 - 000000000009e000 (usable) user: 000000000009e000 - 00000000000a0000 (reserved) user: 00000000000e0000 - 0000000000100000 (reserved) user: 0000000000100000 - 0000000080000000 (usable) 1152MB HIGHMEM available. 896MB LOWMEM available. found SMP MP-table at 0009e140 DMI 2.1 present. ACPI: LAPIC (acpi_id[0x00] lapic_id[0x07] enabled) Processor #7 6:10 APIC version 17 ACPI: LAPIC (acpi_id[0x01] lapic_id[0x00] enabled) Processor #0 6:10 APIC version 17 WARNING: maxcpus limit of 1 reached. Processor ignored. ACPI: LAPIC (acpi_id[0x02] lapic_id[0x01] enabled) Processor #1 6:10 APIC version 17 WARNING: maxcpus limit of 1 reached. Processor ignored. ACPI: LAPIC (acpi_id[0x03] lapic_id[0x02] enabled) Processor #2 6:10 APIC version 17 WARNING: maxcpus limit of 1 reached. Processor ignored. ACPI: LAPIC (acpi_id[0x04] lapic_id[0x03] enabled) Processor #3 6:10 APIC version 17 WARNING: maxcpus limit of 1 reached. Processor ignored. ACPI: LAPIC (acpi_id[0x05] lapic_id[0x04] enabled) Processor #4 6:10 APIC version 17 WARNING: maxcpus limit of 1 reached. Processor ignored. ACPI: LAPIC (acpi_id[0x06] lapic_id[0x05] enabled) Processor #5 6:10 APIC version 17 WARNING: maxcpus limit of 1 reached. Processor ignored. ACPI: LAPIC (acpi_id[0x07] lapic_id[0x06] enabled) Processor #6 6:10 APIC version 17 WARNING: maxcpus limit of 1 reached. Processor ignored. ACPI: LAPIC_NMI (acpi_id[0x00] dfl dfl lint[0x1]) ACPI: LAPIC_NMI (acpi_id[0x01] dfl dfl lint[0x1]) ACPI: LAPIC_NMI (acpi_id[0x02] dfl dfl lint[0x1]) ACPI: LAPIC_NMI (acpi_id[0x03] dfl dfl lint[0x1]) ACPI: LAPIC_NMI (acpi_id[0x04] dfl dfl lint[0x1]) ACPI: LAPIC_NMI (acpi_id[0x05] dfl dfl lint[0x1]) ACPI: LAPIC_NMI (acpi_id[0x06] dfl dfl lint[0x1]) ACPI: LAPIC_NMI (acpi_id[0x07] dfl dfl lint[0x1]) ACPI: IOAPIC (id[0x0e] address[0xfec00000] gsi_base[0]) IOAPIC[0]: apic_id 14, version 19, address 0xfec00000, GSI 0-63 ACPI: INT_SRC_OVR (bus 0 bus_irq 8 global_irq 8 low edge) ACPI: NMI_SRC (dfl dfl global_irq 58) Enabling APIC mode: Flat. Using 1 I/O APICs Using ACPI (MADT) for SMP configuration information Allocating PCI resources starting at 80000000 (gap: 80000000:80000000) Built 1 zonelists Initializing CPU#0 Kernel command line: BOOT_IMAGE=vivek ro BOOT_FILE=/boot/bzImage-2.6.12-rc2-mm1-1M root=/dev/sda3 consle=tty0 console=ttyS0,38400 maxcpus=1 crashkernel=48M@16M mem=2G PID hash table entries: 4096 (order: 12, 65536 bytes) Detected 900.198 MHz processor. Using tsc for high-res timesource Console: colour VGA+ 80x25 Dentry cache hash table entries: 131072 (order: 7, 524288 bytes) Inode-cache hash table entries: 65536 (order: 6, 262144 bytes) Memory: 2024916k/2097152k available (3086k kernel code, 71432k reserved, 1142k data, 232k init, 1179648k highmem) Checking if this processor honours the WP bit even in supervisor mode... Ok. Mount-cache hash table entries: 512 CPU: L1 I cache: 16K, L1 D cache: 16K CPU: L2 cache: 2048K Intel machine check architecture supported. Intel machine check reporting enabled on CPU#0. Enabling fast FPU save and restore... done. Enabling unmasked SIMD FPU exception support... done. Checking 'hlt' instruction... OK. CPU0: Intel Pentium III (Cascades) stepping 04 Total of 1 processors activated (1769.47 BogoMIPS). ENABLING IO-APIC IRQs ..TIMER: vector=0x31 pin1=0 pin2=-1 Brought up 1 CPUs NET: Registered protocol family 16 PCI: PCI BIOS revision 2.10 entry at 0xfd26c, last bus=15 PCI: Using configuration type 1 mtrr: v2.0 (20020519) ACPI: Subsystem revision 20050309 ACPI: Interpreter enabled ACPI: Using IOAPIC for interrupt routing ACPI: PCI Root Bridge [PCI0] (0000:00) PCI: Probing PCI hardware (bus 00) ACPI: Assume root bridge [\_SB_.PCI0] segment is 0 ACPI: Assume root bridge [\_SB_.PCI4] segment is 0 ACPI: Assume root bridge [\_SB_.PCIA] segment is 0 ACPI: Assume root bridge [\_SB_.PCID] segment is 0 ACPI: Can't get handler for 0000:00:02.0 ACPI: Can't get handler for 0000:00:04.0 ACPI: Can't get handler for 0000:00:0e.0 ACPI: Can't get handler for 0000:00:0e.1 ACPI: Can't get handler for 0000:00:0f.1 ACPI: Can't get handler for 0000:00:0f.3 ACPI: Can't get handler for 0000:00:14.0 ACPI: Can't get handler for 0000:00:14.1 ACPI: Can't get handler for 0000:00:19.0 ACPI: PCI Interrupt Link [LKUS] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LKSM] (IRQs *5) ACPI: PCI Interrupt Link [LKSA] (IRQs *15) ACPI: PCI Interrupt Link [LKSB] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LKVI] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LKCA] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LKCB] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LKBA] (IRQs *10) ACPI: PCI Interrupt Link [LKBB] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LKAA] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LKAB] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LKAC] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LKAD] (IRQs 10 11 15) *0, disabled. ACPI: PCI Root Bridge [PCI4] (0000:04) PCI: Probing PCI hardware (bus 04) ACPI: Assume root bridge [\_SB_.PCI0] segment is 0 ACPI: Assume root bridge [\_SB_.PCI4] segment is 0 ACPI: Assume root bridge [\_SB_.PCIA] segment is 0 ACPI: Assume root bridge [\_SB_.PCID] segment is 0 ACPI: PCI Interrupt Link [LK5A] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK5B] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK4A] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK4B] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK4C] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK4D] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK3A] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK3B] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK2A] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK2B] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK1A] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK1B] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK1C] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK1D] (IRQs 10 11 15) *0, disabled. ACPI: PCI Root Bridge [PCIA] (0000:0a) PCI: Probing PCI hardware (bus 0a) ACPI: Assume root bridge [\_SB_.PCI0] segment is 0 ACPI: Assume root bridge [\_SB_.PCI4] segment is 0 ACPI: Assume root bridge [\_SB_.PCIA] segment is 0 ACPI: Assume root bridge [\_SB_.PCID] segment is 0 ACPI: PCI Interrupt Link [LK9A] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK9B] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK8A] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK8B] (IRQs 10 11 15) *0, disabled. ACPI: PCI Root Bridge [PCID] (0000:0d) PCI: Probing PCI hardware (bus 0d) ACPI: Assume root bridge [\_SB_.PCI0] segment is 0 ACPI: Assume root bridge [\_SB_.PCI4] segment is 0 ACPI: Assume root bridge [\_SB_.PCIA] segment is 0 ACPI: Assume root bridge [\_SB_.PCID] segment is 0 ACPI: PCI Interrupt Link [LK7A] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK7B] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK7C] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK7D] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK6A] (IRQs 10 11 15) *0, disabled. ACPI: PCI Interrupt Link [LK6B] (IRQs 10 11 15) *0, disabled. Linux Plug and Play Support v0.97 (c) Adam Belay pnp: PnP ACPI init ACPI: No ACPI bus support for 00:00 ACPI: No ACPI bus support for 00:01 ACPI: No ACPI bus support for 00:02 ACPI: No ACPI bus support for 00:03 ACPI: No ACPI bus support for 00:04 ACPI: No ACPI bus support for 00:05 ACPI: No ACPI bus support for 00:06 ACPI: No ACPI bus support for 00:07 ACPI: No ACPI bus support for 00:08 ACPI: No ACPI bus support for 00:09 ACPI: No ACPI bus support for 00:0a ACPI: No ACPI bus support for 00:0b ACPI: No ACPI bus support for 00:0c ACPI: No ACPI bus support for 00:0d ACPI: No ACPI bus support for 00:0e pnp: PnP ACPI: found 15 devices SCSI subsystem initialized usbcore: registered new driver usbfs usbcore: registered new driver hub PCI: Using ACPI for IRQ routing PCI: If a device doesn't work, try "pci=routeirq". If it helps, post a report PCI: Cannot allocate resource region 4 of device 0000:00:0f.1 pnp: 00:00: ioport range 0x438-0x439 has been reserved pnp: 00:00: ioport range 0x430-0x437 has been reserved pnp: 00:0c: ioport range 0x4d0-0x4d1 has been reserved Machine check exception polling timer started. audit: initializing netlink socket (disabled) audit(1113220570.472:0): initialized highmem bounce pool size: 64 pages inotify device minor=63 Installing knfsd (copyright (C) 1996 okir@monad.swb.de). ACPI: Power Button (FF) [PWRF] ACPI: CPU0 (power states: C1[C1]) ACPI: Processor [CPU7] (supports 8 throttling states) ACPI: CPU0 (power states: C1[C1]) ACPI: Processor [CPU0] (supports 8 throttling states) lp: driver loaded but no devices found Linux agpgart interface v0.101 (c) Dave Jones [drm] Initialized drm 1.0.0 20040925 PNP: PS/2 Controller [PNP0303:PS2K,PNP0f13:PS2M] at 0x60,0x64 irq 1,12 i8042: probe of i8042 failed with error 0 ACPI: No ACPI bus support for i8042 serio: i8042 AUX port at 0x60,0x64 irq 12 serio: i8042 KBD port at 0x60,0x64 irq 1 Serial: 8250/16550 driver $Revision: 1.90 $ 8 ports, IRQ sharing disabled i8042: probe of serial8250 failed with error -19 ACPI: No ACPI bus support for serial8250 ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A ttyS1 at I/O 0x2f8 (irq = 3) is a 16550A pnp: Device 00:04 activated. parport: PnPBIOS parport detected. parport0: PC-style at 0x278 (0x678), irq 7 [PCSPP(,...)] lp0: using parport0 (interrupt-driven). io scheduler noop registered io scheduler anticipatory registered io scheduler deadline registered io scheduler cfq registered ACPI: Floppy Controller [FDC0] at I/O 0x3f0-0x3f5, 0x3f7 irq 6 dma channel 2 Floppy drive(s): fd0 is 1.44M ACPI: No ACPI bus support for serio0 ACPI: No ACPI bus support for serio1 "SYSTEM HANGS AFTER THIS"