dtrace RFE--probe user functions across processes
By uejio on Dec 06, 2005
I finally learned to use dtrace. I attended a talk by Bryan Cantrill on dtrace at a Solaris Desktop Summit organized by John Rice. Bryan is a great speaker. He is incredibly knowledgable, animated, and makes learning dtrace exciting. He covered so much material in a short time that I probably followed only about half of it, but that was enough to get started fiddling with it.
One thing that it would be nice to have in dtrace is the ability to probe user library functions across processes. dtrace does this very nicely for system calls, but not for any arbitrary function in userland. For example, I might want to find out how many calls to some GTK library function were made when logging in to JDS by all GTK apps. I can do this for one app using pid$target, but I couldn't figure out how to do this for multiple apps and aggregate for all apps. Again, this is for any arbitrary function in user space and not system calls. I didn't get a chance to ask Bryan this question, but other dtrace experts said that it can't be done. Rats. (I remember the days when truss couldn't follow user libraries and I was so happy when we added the -u option to trace any lib including a.out.)
I'm still excited about dtrace and look forward to using it in my daily work. Thanks Bryan!
I should also remember to blog about the Solaris Desktop Summit which so far has been a great success...