• Steven Rostedt (Red Hat)'s avatar
    tracing: Disable tracing on warning · de7edd31
    Steven Rostedt (Red Hat) authored
    Add a traceoff_on_warning option in both the kernel command line as well
    as a sysctl option. When set, any WARN*() function that is hit will cause
    the tracing_on variable to be cleared, which disables writing to the
    ring buffer.
    This is useful especially when tracing a bug with function tracing. When
    a warning is hit, the print caused by the warning can flood the trace with
    the functions that producing the output for the warning. This can make the
    resulting trace useless by either hiding where the bug happened, or worse,
    by overflowing the buffer and losing the trace of the bug totally.
    Acked-by: default avatarPeter Zijlstra <peterz@infradead.org>
    Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
ftrace.h 25.8 KB