To support live monitoring of kernel lock contention without BPF,
it should support something like below:

  # perf lock record -a -o- sleep 1 | perf lock contention -i-
   contended   total wait     max wait     avg wait         type   caller

           2     10.27 us      6.17 us      5.13 us     spinlock   load_balance+0xc03
           1      5.29 us      5.29 us      5.29 us     rwlock:W   ep_scan_ready_list+0x54
           1      4.12 us      4.12 us      4.12 us     spinlock   smpboot_thread_fn+0x116
           1      3.28 us      3.28 us      3.28 us        mutex   pipe_read+0x50

To do that, it needs to handle HEAD_ATTR, HEADER_EVENT_UPDATE and
HEADER_TRACING_DATA which are generated only for the pipe mode.
And setting event handler also should be delayed until it gets the
event information.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221104051440.220989-1-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>