An Example of Parallel Processing

This post shows how to use parallel processing to get a CPU intensive job done faster in Unix/Linux. By splitting a large task into several parts, it is quite easy to give each part to a separate CPU, and complete the task many times faster than it would on a single processor.

These days, even small PCs and other devices often come equipped with several CPU cores. But some tasks will use only one core, sometimes using 100% of it, while other cores stand by idle. Sometimes this is a waste of resources. Continue reading

Linux does not see all memory

The other day I upgraded the memory in a customer’s Linux system from 2 to 8 Gb. Afterwards though, only 4 Gb was “visible”. The “free” and “top” commands confirmed that only half the expected memory was there. The system was running 32 bit Red Hat 4.7 in a vmware virtual machine. Continue reading