• Philippe Gerum's avatar
    ipipe: add latency tracer · 798079bc
    Philippe Gerum authored
    The latency tracer is a variant of ftrace's 'function' tracer
    providing detailed information about the current interrupt state at
    each function entry (i.e. virtual interrupt flag and CPU interrupt
    disable bit). This commit introduces the generic tracer code, which
    builds upon the regular ftrace API.
    The arch-specific code should provide for ipipe_read_tsc(), a helper
    routine returning a 64bit monotonic time value for timestamping
    purpose. HAVE_IPIPE_TRACER_SUPPORT should be selected by the
    arch-specific code for enabling the tracer, which in turn makes
    CONFIG_IPIPE_TRACE available from the Kconfig interface.