Does anyone know if any mmap support can be added in .ko to allow for read, write of msr be done via pointer dereferencing instead of ioctl?
I think that is be much less overhead for profiling if possible.
I think that is be much less overhead for profiling if possible.
But if your goal is to reduce overhead, you can read the performance counters with 'rdpmc', which can be configured to be usable from Ring 3 (user level). This is a route that I'm currently pursuing. More details in some of the messages here: https://groups.google.com/forum/#!forum/likwid-developers
This link about mapping PCI configuration space to be accessible to non-root users might be useful too: http://www.cs.usfca.edu/~cruse/cs698f11/uhci.c