About Peter Lawrey
Performance profiling a new machine
When I work on a new machine, I like to get an understanding of it’s limitations. In this post I am looking at the jitter on the machine and the impact of busy waiting for a new PC I built this weekend. The specs for the machine are interesting but not the purpose of the post. Never the less they are:
- i7-3970X six core running at 4.5 GHz (with HT turned on)
- 32 GB of PC-1600 memory
- An OCZ RevoDrive 3, PCI SSD (actual write bandwidth of 600 MB/s)
- Ubuntu 13.04
Note: the OCZ RevoDrive is not officially supported on Linux, but is much cheaper than their models which are.
Tests for jitter
My micro jitter sampler looks at interrupts to a running thread. It is similar to jHiccup but instead of measuring how delayed a thread is in waking up, it measures how delays a thread gets once it has started running. Surprisingly how you run your threads impacts the sort of delays it will see once it wakes up.
Source : http://www.javacodegeeks.com/2013/07/micro-jitter-busy-waiting-and-binding-cpus.html
