Hi, I am learning ftrace. I would like to know to use frace filters for tracing a module's init function. For example, assume the module uvcvideo. While the module is loaded, cat available_filter_functions | grep uvcvideo will give me a big list of functions. Then I enable those functions by setting ftrace filter with: echo "uvc*" > set_ftrace_filter However, as soon as I rmmod the driver, set_ftrace_filter becomes empty automatically. So how do I do a trace on out-of-tree modules I have ? -- Thanks and Regards, Aurabindo J
However, as soon as I rmmod the driver, set_ftrace_filter becomes empty automatically.
Out-of-tree means the module is not build together with the kernel.
So how do I do a trace on out-of-tree modules I have ?
If you built your driver without building it together with the kernel, you can trace it as any other module after you insmod it. Cheers, Abel
On 10 December 2015 at 18:49, Abel Vesa <abelvesa@gmail.com> wrote:
However, as soon as I rmmod the driver, set_ftrace_filter becomes empty automatically.
Out-of-tree means the module is not build together with the kernel.
So how do I do a trace on out-of-tree modules I have ?
If you built your driver without building it together with the kernel, you can trace it as any other module after you insmod it.
Cheers, Abel
I would like to know about both the cases - in tree and out of tree modules: Assume that I have an in-tree module, and I need to do tracing on it right from the start, including its init. Those functions are only detected in available_filter_functions if the module is inserted. If the module i already inserted, I cant trace the init function anymore since the init has already finished. What is the solution with ftrace? Or should I resort to some other tracing tool ? -- Thanks and Regards, Aurabindo J
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Abel Vesa -
Jay Aurabind