I found a solution to this problem. Before, I needed to boot with options
noapic nolapic
which caused the machine to bring up one core only. Replacing the boot
options
as follows
noapic nolapic --> pci=assign-busses apicmaintimer idle=poll
reboot=cold,hard
fixed the problem on my machine. Since I got both cores running quite
recently
only, I think I will stay with the working configuration for a while before
upgrading to
the Ubuntu version 9.10



On Fri, Dec 18, 2009 at 1:48 AM, malev <email address hidden> wrote:

> Thank you for taking the time to report this bug and helping to make
> Ubuntu better. You reported this bug a while ago and there hasn't been
> any activity in it recently. We were wondering if this is still an issue
> for you. Can you try with the latest Ubuntu release? Thanks in advance.
>
> ** Changed in: ubuntu
>       Status: Confirmed => Incomplete
>
> --
> After upgrade to version 9.04, Ubuntu uses only one processor.
> https://bugs.launchpad.net/bugs/371210
> You received this bug notification because you are a direct subscriber
> of the bug.
>
> Status in Ubuntu: Incomplete
>
> Bug description:
> I have run Ubuntu 8.10 on my Packard Bell EasyNote MH-35 laptop without
> problems. After upgrading to Ubuntu version 9.04, lap-top is slow and uses
> only one core. The processor is Intel Core Duo T8100. I have to use noapic
> nolapic boot options to get Ubuntu booting (also in the 8.10 version). I
> have tried to disable the USB mouse and keyboard support in BIOS (this was
> suggested as a solution on another lap-top) but in this case the system
> refuses to boot.
> Below some more info.
>
> # cat /proc/cpuinfo
> processor       : 0
> vendor_id       : GenuineIntel
> cpu family      : 6
> model           : 23
> model name      : Intel(R) Core(TM)2 Duo CPU     T8100  @ 2.10GHz
> stepping        : 6
> cpu MHz         : 1200.000
> cache size      : 3072 KB
> physical id     : 0
> siblings        : 1
> core id         : 0
> cpu cores       : 1
> apicid          : 0
> initial apicid  : 0
> fdiv_bug        : no
> hlt_bug         : no
> f00f_bug        : no
> coma_bug        : no
> fpu             : yes
> fpu_exception   : yes
> cpuid level     : 10
> wp              : yes
> flags           : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov
> pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc
> arch_perfmon pebs bts pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr
> pdcm sse4_1 lahf_lm ida tpr_shadow vnmi flexpriority
> bogomips        : 4200.11
> clflush size    : 64
> power management:
>
> # dmesg | grep -i cpu
> [    0.000000] Initializing cgroup subsys cpuset
> [    0.000000] Initializing cgroup subsys cpu
> [    0.000000] KERNEL supported cpus:
> [    0.000000]   Transmeta TransmetaCPU
> [    0.000000] ACPI: SSDT B7D9924D, 025F (r1  PmRef  Cpu0Tst     3000 INTL
> 20050228)
> [    0.000000] ACPI: SSDT B7D991A7, 00A6 (r1  PmRef  Cpu7Tst     3000 INTL
> 20050228)
> [    0.000000] ACPI: SSDT B7D99101, 00A6 (r1  PmRef  Cpu6Tst     3000 INTL
> 20050228)
> [    0.000000] ACPI: SSDT B7D9905B, 00A6 (r1  PmRef  Cpu5Tst     3000 INTL
> 20050228)
> [    0.000000] ACPI: SSDT B7D98FB5, 00A6 (r1  PmRef  Cpu4Tst     3000 INTL
> 20050228)
> [    0.000000] ACPI: SSDT B7D98F0F, 00A6 (r1  PmRef  Cpu3Tst     3000 INTL
> 20050228)
> [    0.000000] ACPI: SSDT B7D98E69, 00A6 (r1  PmRef  Cpu2Tst     3000 INTL
> 20050228)
> [    0.000000] ACPI: SSDT B7D98DC3, 00A6 (r1  PmRef  Cpu1Tst     3000 INTL
> 20050228)
> [    0.000000] ACPI: SSDT B7D979A9, 141A (r1  PmRef    CpuPm     3000 INTL
> 20050228)
> [    0.000000] Processor #0 (Bootup-CPU)
> [    0.000000] SMP: Allowing 2 CPUs, 0 hotplug CPUs
> [    0.000000] PERCPU: Allocating 45056 bytes of per cpu data
> [    0.000000] NR_CPUS: 64, nr_cpu_ids: 2, nr_node_ids 1
> [    0.000000] Initializing CPU#0
> [    0.004000] SLUB: Genslabs=12, HWalign=64, Order=0-3, MinObjects=0,
> CPUs=2, Nodes=1
> [    0.004000] HPET: 3 timers in total, 0 timers will be used for per-cpu
> timer
> [    0.004000] Initializing cgroup subsys cpuacct
> [    0.004000] CPU: L1 I cache: 32K, L1 D cache: 32K
> [    0.004000] CPU: L2 cache: 3072K
> [    0.004000] CPU: Physical Processor ID: 0
> [    0.004000] CPU: Processor Core ID: 0
> [    0.532470] Brought up 1 CPUs
> [    0.532488] CPU0 attaching NULL sched-domain.
> [    0.568016] Switched to high resolution mode on CPU 0
> [    1.643118] cpufreq: No nForce2 chipset.
> [    1.664851] ACPI: SSDT B7D99D67, 0261 (r1  PmRef  Cpu0Ist     3000 INTL
> 20050228)
> [    1.668409] ACPI: SSDT B7D994AC, 0518 (r1  PmRef  Cpu0Cst     3001 INTL
> 20050228)
> [    1.671438] ACPI: CPU0 (power states: C1[C1] C2[C2] C3[C3])
> [    1.671480] processor ACPI_CPU:00: registered as cooling_device1
> [    1.671488] ACPI: Processor [CPU0] (supports 8 throttling states)
> [    2.796475] cpuidle: using governor ladder
> [    2.796566] cpuidle: using governor menu
> [   43.694069] CPU0 attaching NULL sched-domain.
> [   43.694140] CPU0 attaching NULL sched-domain.
>
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>