Concurrent processes do not utilize all available CPU

Posted by metdos on Stack Overflow See other posts from Stack Overflow or by metdos
Published on 2013-11-11T15:13:22Z Indexed on 2013/11/11 15:53 UTC
Read the original article Hit count: 113

Filed under:

process

|

amazon-ec2

|

virtual-machine

|

cpu

|

cpu-usage

I run some processes on an EC2 cc2.8xlarge instance which has 32 virtual processors.

For some type of processes, when I run 16 processes on parallel, all of them use 100% of CPU cycles. But for other type of processes, they are not using 100% CPU and they finish considerably slower than a single thread.

There is no time spend on IO and all data is served from memory. Do you have any idea about the reason of this problem?

© Stack Overflow or respective owner

Related posts about process

Enterprise Process Maps: A Process Picture worth a Million Words

as seen on Oracle Blogs - Search for 'Oracle Blogs'
p { margin-bottom: 0.08in; }h1 { margin-top: 0.33in; margin-bottom: 0in; color: rgb(54, 95, 145); page-break-inside: avoid; }h1.western { font-family: "Cambria",serif; font-size: 14pt; }h1.cjk { font-family: "DejaVu Sans"; font-size: 14pt; }h1.ctl { font-size: 14pt; } Getting Started with Business… >>> More
Issues with signal handling [closed]

as seen on Programmers - Search for 'Programmers'
I am trying to actually study the signal handling behavior in multiprocess system. I have a system where there are three signal generating processes generating signals of type SIGUSR1 and SIGUSR1. I have two handler processes that handle a particular type of signal. I have another monitoring process… >>> More
Cannot login to Ubuntu 14.04 returns to the login screen

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I updated to 14.04 from 12.04.03. I was using cinammon at that time. When I upgraded to 14.04 ,I got a serious problem. I was unable to login, as whenever I hit enter after entering password, it is taking me straight to login screen again.I unable to login like Guest even. So, here is my .xsession-errors… >>> More
aide --init show lots of errors

as seen on Server Fault - Search for 'Server Fault'
I have a brand new centos 6.2 server. The first thing I did is yum -y install aide and then next I did aide --init. Below is a whole lot of errors I got.What does it means must I reinstall it? Or leave it ? /usr/sbin/prelink: /usr/sbin/lusermod: at least one of file's dependencies has changed since… >>> More
logon process process name RASMAN

as seen on Server Fault - Search for 'Server Fault'
today when i check my event log on windows 2003 server i found this event i am not sure what is this can you explain what is this event for ? Thanks >>> More

Related posts about amazon-ec2

Amazon EC2 spot instances - is there a catch ?

as seen on Server Fault - Search for 'Server Fault'
I needed to start a new EC2 instance today and decided to try out the new spot instances, where you can reduce your instance cost by bidding on the maximum per-hour price you're prepared to pay. Since today's spot price was only 35c / hour, compared with 85c / hour for an on-demand instance, I was… >>> More
Amazon EC2 spot instances - is there a catch ?

as seen on Server Fault - Search for 'Server Fault'
I needed to start a new EC2 instance today and decided to try out the new spot instances, where you can reduce your instance cost by bidding on the maximum per-hour price you're prepared to pay. Since today's spot price was only 3.5c / hour, compared with 8.5c / hour for an on-demand instance, I… >>> More
Amazon EC2 master node hanging

as seen on Server Fault - Search for 'Server Fault'
Hi, I am using cloudera setup to launch a cluster with hadoop on Amazon. Sometimes, the master hadoop node hangs and we have to restart the job from the job. Did anyone face similar problem and resolve the issue. Thank you. >>> More
Can't Connect to IIS Ftp Site under Amazon EC2

as seen on Server Fault - Search for 'Server Fault'
IIS 7.5: Ftp Firewall Suport: Data Ranges 49152-65535 using external Ip of Amazon EC2 static IP Ftp IPv4 Restriction: allow: Amazon EC2 static IP Ftp Authentication: Anonymous: Enabled, Basic: Disabled, IISMgr: Enabled Ftp Authorization: Allow All Users: Read/Write Windows Firewall (Inbound): Open… >>> More
Amazon EC2 EBS volume scheduled backup/snapshots using puppet

as seen on Server Fault - Search for 'Server Fault'
I am not a Linux admin, although I wish I was, and I have seen these questions Amazon EC2 Backup Strategy Amazon EC2 + EBS:: Regular backup plan? Simple Backup Strategy for Amazon EC2 instances / volumes? And this suggestion http://alestic.com/2009/09/ec2-consistent-snapshot I tried using… >>> More