Thanks very much. I will give it a try. My system is a N:1 platform running 2.4 kernel.
I find very few options/tools/libraries on the net regarding process profiling. This brings me to think of how profiling is done on embedded systems (or they never do?) regards, On Tue, Aug 17, 2010 at 11:22 PM, Mulyadi Santosa <[email protected] > wrote: > On Wed, Aug 18, 2010 at 00:16, Ashwath <[email protected]> wrote: > > Hi All, > > > > I am writing a profiler for an embedded application running on linux and > I > > need to detect thread context switches. > > Threading is done using pThread library > > Since I am not sure the way Linux works on your embedded platform, > perhaps you need to find it out first: is your platform use N:1 thread > approach? 1:1? Or M:N (very unlikely, but who knows?) > > Assuming 1:1, like our current NPTL does in normal (non embedded ) IBM > PC x86 compatible, thread switch is basically a schedule() too. Thus, > put a hook in schedule in kernel space, that should do it. > > If N:1, then it must be the master thread that does the switch. Try to > strace your application (the master thread) and try to figure out the > time this thread does something can be indicated as "switching". Quite > likely it is done using ptrace. > > Then, you might need to hook ptrace ( harder) or find a function that > call it and hook it there (perhaps easier). > > -- > regards, > > Mulyadi Santosa > Freelance Linux trainer and consultant > > blog: the-hydra.blogspot.com > training: mulyaditraining.blogspot.com >
