Archive for March, 2009|Monthly archive page
One of the ways in which we highlighted this performance issue was to take advantage of the System Profiler’s Trace Search and the new Path Manager trace events that are available in the 6.4.0 Neutrino kernel. This search gives us a quick view into what files are being opened up
These search results give us very usefull information, but they are kind of isolated. One of the neat things that the Trace Search dialog allows you to do is to combine search conditions together using the && and || operators to AND and OR conditions which can give your search results a bit more of an impact.
For example, if we wanted to get a rough estimate of the kind of effect that each of these file opens was having on our system, then we might do a compound search joining both the FileOpen information with the number of times that we perform a ConnectAttach to actually establish a connection to a server:
Then enter a compound condition:
Now when we do our search, we get a much more interesting set of results that gives us an indication of just how many different servers might be involved when we are doing all of this additional file access:
I’ve cut out some of the columns here to try and fit the content in, but we can now see the FileOpen results with the ConnectAttach() calls inter-mingled. The handy thing with this information is that you can now quickly establish a few cost metrics based on the observed results. This can be handy when you are trying to determine what areas may be worth persuing for further optimization gains.