I have a daemon app written in C and is currently running with no known issues on a Solaris 10 machine. I am in the process of porting it over to Linux. I have had to make minimal changes. During testing it passes all test cases. There are no issues with its functionality. However, when I view its CPU usage when 'idle' on my Solaris machine it is using around .03% CPU. On the Virtual Machine running Red Hat Enterprise Linux 4.8 that same process uses all available CPU (usually somewhere in the 90%+ range).

My first thought was that something must be wrong with the event loop. The event loop is an infinite loop ( while(1) ) with a call to select(). The timeval is setup so that timeval.tv_sec = 0 and timeval.tv_usec = 1000. This seems reasonable enough for what the process is doing. As a test I bumped the timeval.tv_sec to 1. Even after doing that I saw the same issue.

Is there something I am missing about how select works on Linux vs. Unix? Or does it work differently with and OS running on a Virtual Machine? Or maybe there is something else I am missing entirely?

One more thing I am sure sure which version of vmware server is being used. It was just updated about a month ago though.

Thanks.