[SOLVED] Need help in identifying the number of cores in each processor running

srajeshkumar · 12-20-2010, 07:20 AM

Hi All,

I need your help in identifying the number of cores each processor is running.

I have checked /proc/cpuinfo but i dont find any core details inside it and I can find only no of processor and its speed, please help me on this.

Thanks

tronayne · 12-20-2010, 08:40 AM

There is a really handy utility, GKrellM (see http://members.dslextreme.com/users/...m/gkrellm.html) that you might find useful -- it shows every core with an indication of how busy it is along with a graph of activity along with other system activity displays. I just start it up and let it run in a corner of the screen and keep an eye on it.

Hope this helps some.

TB0ne · 12-20-2010, 09:24 AM

Quote:

Originally Posted by srajeshkumar

Hi All,
I need your help in identifying the number of cores each processor is running.
I have checked /proc/cpuinfo but i dont find any core details inside it and I can find only no of processor and its speed, please help me on this.
Thanks

Each 'core' will show up as a separate processor. For example, on my Core i7, I ran "cat /proc/cpuinfo | grep processor" and it shows items 0-7 (8 total devices, one for the actual 'chip', and one for each core). You can also use "dmesg | grep CPU".

Pay attention to what info is in the cpuinfo file...all you're asking for is there.

Subject16 · 12-20-2010, 10:09 AM

Chiming in, if you cat /proc/cpuinfo, the specific lines I think you want to look for are physical id (helps you differentiate between the actual physical processors in your system; same physical processor shares same physical id); cpu cores tells you how many cores are on that physical cpu, and core id even tells which core the output is talking about. But specifically for your question the "cpu cores" line in that output oughta tell you what you need to know.

Steviepower · 12-20-2010, 10:29 AM

this script I found checks how many cores a cpu has and then starts as many tests as there are cores.

Quote:

N=`cat /proc/cpuinfo | grep processor | wc -l`

cat /proc/cpuinfo | grep "model name"
echo
echo "Calculating the first 5000 decimals of pi using $N parallel processes"
TimeBegin=`date +%s.%N`

for ((i=1; i<=$N; i++))
do
echo "scale=5000; 4*a(1)" | bc -l -q > /dev/null &
done
wait

TimeEnd=`date +%s.%N`
DT=`echo "scale=2; ($TimeEnd - $TimeBegin) / 1" | bc`
echo "Total time: $DT seconds"
DTc=`echo "scale=2; ($TimeEnd - $TimeBegin) / $N" | bc`
echo "Average time per calculation: $DTc seconds"

I think what you're looking for is N

I don't really know what TB0ne here means with one for each core and one for each processor. but it just shows the cpu cores that are presented to the kernel to do their work on. if you have 1 cpu with 2 cores it says 2 if you have 2 cpu's with 1 core it says 2 and if you have 1 cpu and one core with hyperthreading it says 2 as well. if you have 2 cpu's with 6 cores and hyperthreading on all of them it says 24. so all you need to do to know the actual number of cores is this and divide it by two if you have hyperthreading.
You can check this by seeing if the cpu has the ht flag.

TB0ne · 12-20-2010, 11:13 AM

Quote:

Originally Posted by Steviepower

this script I found checks how many cores a cpu has and then starts as many tests as there are cores.

I think what you're looking for is N

I don't really know what TB0ne here means with one for each core and one for each processor. but it just shows the cpu cores that are presented to the kernel to do their work on. if you have 1 cpu with 2 cores it says 2 if you have 2 cpu's with 1 core it says 2 and if you have 1 cpu and one core with hyperthreading it says 2 as well. if you have 2 cpu's with 6 cores and hyperthreading on all of them it says 24. so all you need to do to know the actual number of cores is this and divide it by two if you have hyperthreading.
You can check this by seeing if the cpu has the ht flag.

+1. Good post, Steviepower.

Reuti · 12-21-2010, 06:17 AM

Quote:

Originally Posted by Steviepower

This script I found checks how many cores a cpu has and then starts as many tests as there are cores. You can check this by seeing if the cpu has the ht flag.

For Intel CPUs, otherwise it can mean HyperTransport: http://blog.incase.de/index.php/cpu-...heir-meanings/ And HyperThreading may also be switched off in the BIOS, but the flag will still be output.

If the original poster is looking for something like the topology, I would just like to note, that in the GridEngine package the tool loadcheck will output something like:

Code:

$ /usr/sge/utilbin/lx24-amd64/loadcheck 
arch            lx24-amd64
num_proc        8
m_socket        2
m_core          8
m_topology      SCCCCSCCCC
...

Steviepower · 12-23-2010, 09:52 AM

ok I didn't know that, good you do.