All generalizations are incorrect Charles Suresh's blog

I've recently begun looking at ZFS performance (in the context of MySQL usage). Being a ZFS newbie, I needed to look at what parts of the code are being exercised. Using a tool chain that consisted of sysbench, dtrace, perl and graphviz here's what I get:

Note: If the image doesn't fully render in your browser, you can download it Some details on how this map was generated:

I used dtrace to get callstacks during a sysbench run that exercises MySQL. The callstacks from dtrace were fed to perl to generate a closure of all functions that call into ZFS functions. The output from perl was a call graph which was fed to graphviz to generate the flowchart shown above.

Note that some GIGO is apparent in the graph where a few parent functions appear to be calling a grandchild function in addition to a child function. This is due to bugid:6713149 x64 kernel profile call stacks missing a frame