RE: Processor Speed on Linux

  • From: "Marquez, Chris" <cmarquez@xxxxxxxxxxxxxxxx>
  • To: <bdbafh@xxxxxxxxx>, <dbvision@xxxxxxxxxxxx>
  • Date: Wed, 17 Aug 2005 11:43:48 -0400

Paul & Nuno,

Good stuff thanks!

---Easy to see/remember.
[oracle@db02 oracle]$ dmesg | grep runq
mapping CPU#0's runqueue to CPU#2's runqueue.
mapping CPU#1's runqueue to CPU#3's runqueue.


---Little harder to remember.
[oracle@db02 oracle]$ cat /proc/cpuinfo | grep flags
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
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
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
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



-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx on behalf of Paul Drake
Sent: Wed 8/17/2005 9:40 AM
To: dbvision@xxxxxxxxxxxx
Cc: oracle-l@xxxxxxxxxxxxx
Subject: Re: Processor Speed on Linux
 
On 8/17/05, Nuno Souto <dbvision@xxxxxxxxxxxx> wrote:
> Marquez, Chris apparently said,on my timestamp of 17/08/2005 2:30 AM:
> > Be careful...with Intel HYPER THREADING two physical CPU is reported and
> > seen as four physical CPU.
> >
> 
> 
> When you do cat /proc/cpuinfo, check out the flags field.
> If it has the string "ht" in it, it's a hyper thread chip.
> 
> --
> Cheers
> Nuno Souto
> in sunny Sydney, Australia
> dbvision@xxxxxxxxxxxx

Also-

check dmesg for mapping of the hyperthreaded cpu onto the runqueue of
the physical processor. In top, one can see on a lightly loaded
server, processes run on the 2 physical CPUs first (on a RHEL ES
kernel - update 5).

Paul
--
//www.freelists.org/webpage/oracle-l


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