• Steven Rostedt's avatar
    tracing: use timestamp to determine start of latency traces · 2f26ebd5
    Steven Rostedt authored
    Currently the latency tracers reset the ring buffer. Unfortunately
    if a commit is in process (due to a trace event), this can corrupt
    the ring buffer. When this happens, the ring buffer will detect
    the corruption and then permanently disable the ring buffer.
    
    The bug does not crash the system, but it does prevent further tracing
    after the bug is hit.
    
    Instead of reseting the trace buffers, the timestamp of the start of
    the trace is used instead. The buffers will still contain the previous
    data, but the output will not count any data that is before the
    timestamp of the trace.
    
    Note, this only affects the static trace output (trace) and not the
    runtime trace output (trace_pipe). The runtime trace output does not
    make sense for the latency tracers anyway.
    Reported-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
    2f26ebd5
trace_sched_wakeup.c 8.89 KB