So what *exactly* happened when it failed to work? The patch didn't apply? The kernel wouldn't compile? won't boot? Boots but no realtime? Any error messages? What suggested that TRACE_IRQFLAGS would make a difference? Xenomai patching succeeded but when running one of is test apps, "latency" showing
0"000.000| BUG in low_init(): [main] mlockall: Cannot allocate memory And the mailing list member suggested the following
"The problematic option is CONFIG_TRACE_IRQFLAGS, not
CONFIG_CONTEXT_TRACKING, and you have it enabled, since without it, you would not be able to enable CONFIG_LOCKDEP. Please disable CONFIG_TRACE_IRQFLAGS. You will need to disable all the options depending on that option, such as CONFIG_LOCKDEP."
First thing to do is to verify that you *really* need the patch at all. 95% of people who think they need special real-time patches don't actually need them. Linux already has fairly good soft real-time support, which is good for most stuff. Experimenting for automation and for educational purposes.