Just a wild idea, but you might try booting into an older kernel (if you system is a few months old, you should have several kernel options when you boot) and run the mpstat command under a different kernel version.
Iced Blended Vanilla Crème Ubuntu
Just a wild idea, but you might try booting into an older kernel (if you system is a few months old, you should have several kernel options when you boot) and run the mpstat command under a different kernel version.
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A Carafe of Ubuntu
there should be one folder for each core in:
/sys/devices/system/cpu
i have 2 cores so i have the folders:
/sys/devices/system/cpu/cpu0
/sys/devices/system/cpu/cpu1
all cores except "cpu0" should have a file called online in them
if that file contains a zero the core will be offline, so try:
cat /sys/devices/system/cpu/cpu1/online
cat /sys/devices/system/cpu/cpu2/online
cat /sys/devices/system/cpu/cpu3/online
if it says "0" change them to "1" by opening a root terminal and typing:
echo "1" > /sys/devices/system/cpu/cpu1/online
IT HAS TO BE A ROOT TERMINAL, sudo wont work...not really sure why but it
has something to do with the ">"
if this doesnt work or if u dont even have one folder for each core in
/sys/devices/system/cpu/ then i have no clue, perhaps a reinstall??
Quad Shot of Ubuntu
Your kernel version looks fine:
2.6.27-9-generic #1 SMP
It's possible to disable SMP (and hence multi-core support) at boot time. Did you make any changes to your grub configuration?
Also, start up top from the a shell (command-line). By default it doesn't show all the cores, but if you press "1" it'll show all the CPU/Core's and load on each one. Try and see if you see more than one Core.
A Carafe of Ubuntu
I've only got one cpuN device in /sys/devices/cpu/. A reinstall is pathetic at this point, since I KNOW it was working with this very kernel previously. I tried downgrading to the 2.6.27-9 kernel, to no avail.Originally Posted by anders_c_
Here's output of various commands. lshw apparently shows that I should be seeing all four cores, but the kernel et al. show nothing:
I KNOW it was working before, and the only thing I really changed was a routine kernel upgrade. I'm wondering if this is a bug? Or a failing chip? I dunno...Code:amphetamine:~ # cat /proc/cpuinfo processor : 0 vendor_id : AuthenticAMD cpu family : 16 model : 2 model name : AMD Phenom(tm) 9950 Quad-Core Processor stepping : 3 cpu MHz : 2600.000 cache size : 512 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 : 5 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm 3dnowext 3dnow constant_tsc pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs bogomips : 5199.85 clflush size : 64 power management: ts ttp tm stc 100mhzsteps hwpstate amphetamine:~ # lshw -class cpu *-cpu:0 description: CPU product: AMD Phenom(tm) 9950 Quad-Core Processor vendor: Advanced Micro Devices [AMD] physical id: 3 bus info: cpu@0 version: 15.2.3 slot: Socket AM2 size: 2600MHz capacity: 2600MHz width: 64 bits clock: 200MHz capabilities: boot fpu fpu_exception wp vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp x86-64 3dnowext 3dnow constant_tsc pni monitor cx16 popcnt lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs cpufreq *-cpu:1 physical id: 4 bus info: cpu@1 version: 15.2.3 size: 18EHz *-cpu:2 physical id: 5 bus info: cpu@2 version: 15.2.3 size: 18EHz *-cpu:3 physical id: c bus info: cpu@3 version: 15.2.3 size: 18EHz *-processor UNCLAIMED description: Co-processor product: MCP78S [GeForce 8200] Co-Processor vendor: nVidia Corporation physical id: 1.3 bus info: pci@0000:00:01.3 version: a2 width: 32 bits clock: 66MHz capabilities: bus_master configuration: latency=0 maxlatency=1 mingnt=3
Just Give Me the Beans!
I only have a folder named cpu0 and another named cpuidle in /sys/devices/system/cpu. I have made changes to grub. I recently installed Windows over Ubuntu and had to make some changes for it to work.
I'm not sure how to start up form the shell. Do you mean login without X?Also, start up top from the a shell (command-line). By default it doesn't show all the cores, but if you press "1" it'll show all the CPU/Core's and load on each one. Try and see if you see more than one Core.
Last edited by walawa; February 8th, 2009 at 01:56 AM.
Extra Roomy Joe
On a dual core processor, this is the output of "dmesg | grep -i cpu":
Notice the line that says "Brought up 2 CPUs".Code:% dmesg | grep -i cpu [ 0.000000] Initializing cgroup subsys cpuset [ 0.000000] Initializing cgroup subsys cpu [ 0.000000] ACPI: SSDT 3FEE7CA0, 0380 (r1 PmRef CpuPm 3000 INTL 20040311) [ 0.000000] SMP: Allowing 4 CPUs, 2 hotplug CPUs [ 0.000000] PERCPU: Allocating 41628 bytes of per cpu data [ 0.000000] NR_CPUS: 64, nr_cpu_ids: 4, nr_node_ids 1 [ 0.000000] Initializing CPU#0 [ 0.004000] SLUB: Genslabs=12, HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1 [ 0.004000] Initializing cgroup subsys cpuacct [ 0.004000] CPU: L1 I cache: 32K, L1 D cache: 32K [ 0.004000] CPU: L2 cache: 1024K [ 0.004000] CPU: Physical Processor ID: 0 [ 0.004000] CPU: Processor Core ID: 0 [ 0.433808] CPU0: Intel(R) Pentium(R) Dual CPU E2160 @ 1.80GHz stepping 0d [ 0.004000] Initializing CPU#1 [ 0.004000] CPU: L1 I cache: 32K, L1 D cache: 32K [ 0.004000] CPU: L2 cache: 1024K [ 0.004000] CPU: Physical Processor ID: 0 [ 0.004000] CPU: Processor Core ID: 1 [ 0.520411] CPU1: Intel(R) Pentium(R) Dual CPU E2160 @ 1.80GHz stepping 0d [ 0.520428] checking TSC synchronization [CPU#0 -> CPU#1]: passed. [ 0.524055] Brought up 2 CPUs [ 0.524080] CPU0 attaching sched-domain: [ 0.524093] CPU1 attaching sched-domain: [ 0.576042] Switched to high resolution mode on CPU 0 [ 0.576457] Switched to high resolution mode on CPU 1 [ 2.148572] cpuidle: using governor ladder [ 2.148575] cpuidle: using governor menu [ 2.275330] ACPI: SSDT 3FEE7680, 022A (r1 PmRef Cpu0Ist 3000 INTL 20040311) [ 2.275856] ACPI: SSDT 3FEE7B40, 0152 (r1 PmRef Cpu1Ist 3000 INTL 20040311) [ 3.417141] [<c010288d>] cpu_idle+0x7d/0x140
Sometimes dmesg contains useful error messages.
Perhaps take a look at and post your "dmesg | grep -i cpu"
Also, post
This will tell us which kernel you are using.Code:uname -a
A Carafe of Ubuntu
Yeah, the boot messages say only one CPU has been started. Unfortunately I have no idea why, since it stopped working afaict on its own. Reverting back to a previous kernel doesn't fix it, so I doubt the problem lies in the options compiled into (or left out of) my running kernel.
It seems that WinXP can see all four cores, unless my CPU has failed and Windows just sucks.Code:amphetamine:~ # dmesg | grep -i cpu [ 0.000000] Initializing cgroup subsys cpuset [ 0.000000] Initializing cgroup subsys cpu [ 0.000000] SMP: Allowing 4 CPUs, 0 hotplug CPUs [ 0.000000] PERCPU: Allocating 41628 bytes of per cpu data [ 0.000000] NR_CPUS: 64, nr_cpu_ids: 4, nr_node_ids 1 [ 0.000000] Kernel command line: root=UUID=5b026cc0-09be-4255-8023-54c95619ca42 ro cpus=4 splash [ 0.000000] Initializing CPU#0 [ 0.004000] SLUB: Genslabs=12, HWalign=64, Order=0-3, MinObjects=0, CPUs=4, Nodes=1 [ 0.004000] Initializing cgroup subsys cpuacct [ 0.004000] CPU: L1 I Cache: 64K (64 bytes/line), D cache 64K (64 bytes/line) [ 0.004000] CPU: L2 Cache: 512K (64 bytes/line) [ 0.004000] CPU 0(4) -> Core 0 [ 0.333158] CPU0: AMD Phenom(tm) 9950 Quad-Core Processor stepping 03 [ 16.512119] Brought up 1 CPUs [ 16.512284] CPU0 attaching NULL sched-domain. [ 16.900044] Switched to high resolution mode on CPU 0 [ 17.970274] cpuidle: using governor ladder [ 17.970336] cpuidle: using governor menu [ 51.589855] powernow-k8: Found 1 AMD Phenom(tm) 9950 Quad-Core Processor processors (1 cpu cores) (version 2.20.00) amphetamine:~ # uname -a Linux amphetamine 2.6.27-11-generic #1 SMP Thu Jan 29 19:24:39 UTC 2009 i686 GNU/Linux
Last edited by ectospasm; February 8th, 2009 at 02:42 AM. Reason: forgot to post the output he asked for
Just Give Me the Beans!
Here's the output of dmesg | grep -i cpu:Mine also says only one cpu has been started out of the four.Code:[ 0.000000] Initializing cgroup subsys cpuset [ 0.000000] Initializing cgroup subsys cpu [ 0.000000] SMP: Allowing 1 CPUs, 0 hotplug CPUs [ 0.000000] PERCPU: Allocating 41628 bytes of per cpu data [ 0.000000] NR_CPUS: 64, nr_cpu_ids: 1, nr_node_ids 1 [ 0.000000] Initializing CPU#0 [ 0.004000] SLUB: Genslabs=12, HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1 [ 0.004192] Initializing cgroup subsys cpuacct [ 0.004206] CPU: L1 I cache: 32K, L1 D cache: 32K [ 0.004208] CPU: L2 cache: 4096K [ 0.004210] CPU: Physical Processor ID: 0 [ 0.004211] CPU: Processor Core ID: 0 [ 0.300052] weird, boot CPU (#0) not listedby the BIOS. [ 0.304019] Brought up 1 CPUs [ 0.304019] CPU0 attaching sched-domain: [ 0.304019] domain 0: span 0 level CPU [ 0.928064] Switched to high resolution mode on CPU 0 [ 1.396353] cpuidle: using governor ladder [ 1.396355] cpuidle: using governor menu [ 1.884046] ACPI: Processor [CPU0] (supports 8 throttling states)
My kernel is Linux tristan-desktop 2.6.27-9-generic #1 SMP Thu Nov 20 21:57:00 UTC 2008 i686 GNU/Linux.
I don't know if this has anything to do with it, but I'm using Phoenix BIOS.
Just Give Me the Beans!
I tried booting from an 8.04 LiveCD but system monitor still didn't recognize all 4 cores. Could booting into a more recent LiveCD help?
I've seen posts where booting with acpi off helped. Should I try this?
Would using 64-bit ubuntu help?
Extra Roomy Joe
Try booting with kernel option "noapic".
This is where I'm getting this information:
http://fixunix.com/linux/269544-weir...sted-bios.html
If that does not work, try "acpi=off".
And here are instructions for booting with kernel options:
http://ubuntuforums.org/showpost.php...63&postcount=4
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