tracing: separate out buffer from trace_seq

Quote from Steven:
"""
This is an RFC patch set. The trace_seq currently has its buffer within the structure itself. But this limits its ability and efficiency.

This patch set separates it out, but now it requires the callers to supply their own buffer. But this helps out the splice code because it can now write directly into the splice pages.
"""

Lai Jiangshan (4)
tracing: bug fix, remove partial zeroed out
tracing: event_id_read() uses simple buffer instead of trace_seq
tracing: tracing_stats_read() uses simple buffer instead of trace_seq
tracing: reduce latency and remove percpu trace_seq

Steven Rostedt (2):
tracing: Change trace_seq to use separate buffer
tracing: Write directly into splice page for trace_pipe

---
 include/linux/ftrace_event.h |    9 +++-
 include/linux/trace_seq.h    |   22 +++++++++++-
 include/trace/ftrace.h       |   18 +++------
 kernel/trace/ftrace.c        |    3 +
 kernel/trace/trace.c         |   72 +++++++++++----------------------------
 kernel/trace/trace_events.c  |   78 ++++++++++++++++++++-----------------------
 kernel/trace/trace_ksym.c    |   12 +++---
 kernel/trace/trace_output.c  |   25 ++++++-------
 8 files changed, 110 insertions(+), 129 deletions(-)