TechAgility

Just something worth mentioning that I have come across recently that might be of some help?

I was recently hunting down the exact reason for why a 2533 running RGS across WiFi was struggling to be able to deliver the video content and found that I had to do quite a bit of logging and then gathering the raw data in to an excel sheet to make sense of it all – in the process I ditched PerfMon – in part because it wasn’t working under XPe, but also because I feel its performance can’t be relied on when things are already going wrong, so I had started using TYPEPERF.EXE which is actually installed by default on everything from at least XP onwards.

Then on one of my initial builds of Windows 7 on my laptop I found that on resume it would occasionally appear quite sluggish and when digging deeper this appeared to be caused by 50% of the CPU being consumed by DPC’s (Deferred Procedure Calls). So after ascertaining that Typeperf wouldn’t cut it I started looking deeper for a tool that would help identify exactly what driver was causing this.

So I then discovered this article Measuring DPC time that highlighted the latest tool being Xperf – the main difference is that this is not installed natively in the OS, so you’ll have to go and download it and install it.

The really neat part of this is that it comes with an XPerf viewer that allows you to intuitively drill through the results, highlight particular time slices, overlay multiple graphs, etc.

And as if this isn’t enough, it also allows you to download symbols on the fly exactly like the latest debugging tools so that you can drill in to find the offending file/driver, etc. There is also a similar tool that will allow you to do similar performance tracking at boot time, and from what I can see it is this set of tools that has assisted MS in getting on top of the performance issues from Vista to Windows 7. My understanding at this stage is that this *should* work to capture info in XP (failed for me so far…) 

XPerf:
Windows Performance Toolkit (WPT) – Download
Two Minute Drill: Introduction to XPerf
Using Xperf to take a Trace
Xperf support for XP

Typeperf:
Although it’s not installed/supported in XPe by default it is possible to run it direct from any drive (Temp, USB, etc. ) and collect data
See Two Minute Drill: TYPEPERF for more details

Example:
Check your Total CPU usage every second:
C:\>typeperf "\processor(_Total)\% Processor Time"
"(PDH-CSV 4.0)",\\2K8SRV\processor(_Total)\% Processor Time
"04/13/2009 09:50:04.359","2.509119"
"04/13/2009 09:50:05.360","0.754295"
"04/13/2009 09:50:06.360","2.899090"
"04/13/2009 09:50:07.360","1.534207"
"04/13/2009 09:50:08.360","0.559314"
"04/13/2009 09:50:09.360","10.113409"
"04/13/2009 09:50:10.360","10.113409"
"04/13/2009 09:50:11.360","3.094071"
"04/13/2009 09:50:12.360","0.559314"

I hope this is of some use?

written by dcaddick