RH 7.3, Dual Xeon 2650, 'top' and cpuinfo say I have 4 cpus!

Chris Chabot chabotc at xs4all.nl
Wed Aug 7 08:41:01 CDT 2002


Welcome to 'hyperthreading'. You will notice in your /proc/cpuinfo that 
your xeons have the 'ht' flag set (hyperthreading capable). 
Hyperthreading is an intel invention to use the idle silicon on a 
processor, by making it apear to be 2 processors (this way, any idle 
pipelines and other parts of the chip can do other tasks while the main 
task is bizzy)

Please refer to the linux-poweredge archives if you want to find out 
more, what it does for performance, and how to en/disable it if you 
would want to.. If you want to know more about hyperthreading it self, i 
would sugest intel's own website..

So there's nothing wrong and this is how it is supposed to work, please 
read the kind and friendly words on the hitchhikers guide to Xeon's:  
'Don't panic' ;-)

    -- Chris


Brian K. Jones wrote:

>W'sup with this?  Top and 'cat /proc/cpuinfo' both say I have a Quad
>Xeon box!  I've opened up one of these boxes, and there are only two
>cpus!  Running Redhat 7.3, software RAID 1, stock smp kernel, no crazy
>apps or anything on it at this point - we're just testing them out. 
>Output from the commands are below, if anyone knows that I'm parsing
>this wrong or why Redhat's reporting this, PLEASE let me know!
>
> 9:26am  up 20:09,  1 user,  load average: 0.00, 0.00, 0.00
>63 processes: 62 sleeping, 1 running, 0 zombie, 0 stopped
>CPU0 states:  0.0% user,  0.1% system,  0.0% nice, 99.4% idle
>CPU1 states:  0.0% user,  0.0% system,  0.0% nice, 100.0% idle
>CPU2 states:  0.0% user,  0.0% system,  0.0% nice, 100.0% idle
>CPU3 states:  0.0% user,  0.0% system,  0.0% nice, 100.0% idle
>Mem:  1031008K av,  316812K used,  714196K free,       0K shrd,   63264K
>buff
>Swap: 1534072K av,       0K used, 1534072K free                  125260K
>cached
>
>
>
>
>
>[jonesy at willy jonesy]$ cat /proc/cpuinfo
>processor	: 0
>vendor_id	: GenuineIntel
>cpu family	: 15
>model		: 2
>model name	: Intel(R) XEON(TM) CPU 2.20GHz
>stepping	: 4
>cpu MHz		: 2187.978
>cache size	: 512 KB
>fdiv_bug	: no
>hlt_bug		: no
>f00f_bug	: no
>coma_bug	: no
>fpu		: yes
>fpu_exception	: yes
>cpuid level	: 2
>wp		: yes
>flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
>pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm
>bogomips	: 4364.69
>
>processor	: 1
>vendor_id	: GenuineIntel
>cpu family	: 15
>model		: 2
>model name	: Intel(R) XEON(TM) CPU 2.20GHz
>stepping	: 4
>cpu MHz		: 2187.978
>cache size	: 512 KB
>fdiv_bug	: no
>hlt_bug		: no
>f00f_bug	: no
>coma_bug	: no
>fpu		: yes
>fpu_exception	: yes
>cpuid level	: 2
>wp		: yes
>flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
>pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm
>bogomips	: 4364.69
>
>processor	: 2
>vendor_id	: GenuineIntel
>cpu family	: 15
>model		: 2
>model name	: Intel(R) XEON(TM) CPU 2.20GHz
>stepping	: 4
>cpu MHz		: 2187.978
>cache size	: 512 KB
>fdiv_bug	: no
>hlt_bug		: no
>f00f_bug	: no
>coma_bug	: no
>fpu		: yes
>fpu_exception	: yes
>cpuid level	: 2
>wp		: yes
>flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
>pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm
>bogomips	: 4364.69
>
>processor	: 3
>vendor_id	: GenuineIntel
>cpu family	: 15
>model		: 2
>model name	: Intel(R) XEON(TM) CPU 2.20GHz
>stepping	: 4
>cpu MHz		: 2187.978
>cache size	: 512 KB
>fdiv_bug	: no
>hlt_bug		: no
>f00f_bug	: no
>coma_bug	: no
>fpu		: yes
>fpu_exception	: yes
>cpuid level	: 2
>wp		: yes
>flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
>pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm
>bogomips	: 4364.69
>
>
>  
>






More information about the Linux-PowerEdge mailing list