Why do some software not get load balanced even when there are multiple cores?

Posted by Nav on Super User See other posts from Super User or by Nav
Published on 2011-03-19T07:27:05Z Indexed on 2011/03/19 8:12 UTC
Read the original article Hit count: 227

Filed under:

redhat

|

multi-core

|

load-balancer

|

blade

While VTune Analyzer was running on a blade server with 8 cores, I observed the cpu useage percentage using mpstat -P ALL 1.

mpstat showed me that VTune was taking up 100% of a single core, while all other cores were idle.

Why does that happen? Shouldn't the OS (RHEL Server 5.2) automatically distribute load across cores? The same happened when I tried running MATLAB (even after enabling multithreading support in the MATLAB settings).

p.s: I'm a developer. Not a sys admin. So felt it better to ask here rather than at serverfault.

© Super User or respective owner

Related posts about redhat

Invalid configuration `noarch-redhat-linux-gnu': machine `noarch-redhat' not recognized

as seen on Server Fault - Search for 'Server Fault'
When I try to build rpm from src rpm (Apache 2.4.1) I got this error: rpmbuild -tb httpd-2.4.1.tar.bz2 --ba httpd.spec + ./configure --build=x86_64-redhat-linux-gnu --host=x86_64-redhat-linux-gnu --target=noarch-redhat-linux-gnu --program-prefix= --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin… >>> More
`# probe: true` in /etc/rc.d/init.d/* files on a RedHat system

as seen on Server Fault - Search for 'Server Fault'
Some files (e.g. nfs, nfslock, bind) in my /etc/rc.d/init.d/ directory have in their comment header a line such as: # probe: true I found that those particular scripts has the probe verb i.e.: service nfs probe But this is due to the fact that the mentioned scripts has code that deals with the… >>> More
Redhat Software RAID 1 not syncing

as seen on Server Fault - Search for 'Server Fault'
Hey guys, I setup a software RAID 1 on a Redhat server, everything went sweet and it synced the first time. The other day the raid failedover for some reason and the disks hadn't been syncing since that first time, so it went back to 2 weeks ago when we did the first sync. We got the system back… >>> More
Failed to start X server. REDHAT LINUX 5.3

as seen on Super User - Search for 'Super User'
I installed Red-hat 5.3 problem is that it is not showing graphical interface. only kernel / command prompt is available. I tried startx, then I got this msg No video BIOS modes for chosen depth also showing that ERROR: Failed to start X server. What should I do? >>> More
Problems installing Memcache (PECL extension)

as seen on Server Fault - Search for 'Server Fault'
I have installed memcached fine, and now I will need to install PECL extension memcache. Im running RedHat x86_64 es5. The installation gives me this: downloading memcache-2.2.6.tgz ... Starting to download memcache-2.2.6.tgz (35,957 bytes) ..........done: 35,957 bytes 11 source files, building running:… >>> More

Related posts about multi-core

Programming for Multi core Processors

as seen on Stack Overflow - Search for 'Stack Overflow'
As far as I know, the multi-core architecture in a processor does not effect the program. The actual instruction execution is handled in a lower layer. my question is, Given that you have a multicore environment, Can I use any programming practices to utilize the available resources more effectively… >>> More
Multicore Chips Require OS Rework, Windows Architect Advises

as seen on Devx - Search for 'Devx'
Microsoft's Dave Probert says the OS kernel needs to act more like a hypervisor. >>> More
Multicore Chips Require OS Rework, Windows Architect Advises

as seen on Internet.com - Search for 'Internet.com'
Microsoft's Dave Probert says the OS kernel needs to act more like a hypervisor. >>> More
In a multithreaded app, would a multi-core or multiprocessor arrangement be better?

as seen on Stack Overflow - Search for 'Stack Overflow'
I've read a lot on this topic already both here (e.g., stackoverflow.com/questions/1713554/threads-processes-vs-multithreading-multi-core-multiprocessor-how-they-are or http://stackoverflow.com/questions/680684/multi-cpu-multi-core-and-hyper-thread) and elsewhere (e.g., ixbtlabs.com/articles2/cpu/rmmt-l2-cache… >>> More
Multi core processors... are they really needed?

as seen on Super User - Search for 'Super User'
What things are multi-core processors needed for? I mean what type of things benefit from using multi-core ? Also are there anythings that suffer in performance for using multi-core... ie. they perform better using a single core processor? >>> More