[PATCH v5 0/3] perf synthetic events

[Ian Rogers]

Add a multi-threaded version of the internals synthesize benchmark. It
attempts to compute a time per event synthesized, but as it is reading
/proc there are issues:
 - permissions if not run as root
 - "random" nature of /proc
 
By default the benchmark is disabled but can be enabled with a
flag. It has been useful in gauging the value of multi-threaded
improvements not included here as their value appears minimal.

The patch set includes 2 patches that improve synthesis performance
and updates the benchmark numbers:
https://lore.kernel.org/lkml/20200411064248.247530-1-irogers@xxxxxxxxxx/

v4 added a missing test file
v3 improved documenation, return values and added testing to the io framework
   following feedback from namhyung@xxxxxxxxxxx
v2 addressed single threaded synthesize benchmark issues from jolsa@xxxxxxxxxx
https://lore.kernel.org/lkml/20200402154357.107873-1-irogers@xxxxxxxxxx/

Ian Rogers (3):
  perf bench: add a multi-threaded synthesize benchmark
  tools api: add a lightweight buffered reading api
  perf synthetic events: Remove use of sscanf from /proc reading

 tools/lib/api/io.h                 | 112 +++++++++++
 tools/perf/bench/synthesize.c      | 211 +++++++++++++++++---
 tools/perf/tests/Build             |   1 +
 tools/perf/tests/api-io.c          | 304 +++++++++++++++++++++++++++++
 tools/perf/tests/builtin-test.c    |   4 +
 tools/perf/tests/tests.h           |   1 +
 tools/perf/util/synthetic-events.c | 157 ++++++++++-----
 7 files changed, 713 insertions(+), 77 deletions(-)
 create mode 100644 tools/lib/api/io.h
 create mode 100644 tools/perf/tests/api-io.c

-- 
2.26.0.110.g2183baf09c-goog