[RFC 1/8] perf: Block perf calls for system call tracepoints

[Jiri Olsa]

hi,
Steven asked for possibility to block traced process
in case the tracer can't keep up and we would loose
events.
    
This (RFC) patchset tries to implement this by adding
'block' bool in struct perf_event_attr to be set only
for syscalls tracepoints and adding code to block the
traced process, if there's no space in event's ring
buffer.
    
The blocking code will poll/periodically check for the
space and continue if the event was successfully written.

Available also here:
  git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
  perf/block

Thoughts?

thanks,
jirka


---
Jiri Olsa (8):
      perf: Allow to block process in syscall tracepoints
      perf tools: Sync uapi perf_event.h
      perf record: Add --block option
      perf trace: Add --block option
      perf tools: Add block term support for tracepoints
      perf tools: Add ordered_events__flush_time interface
      perf trace: Move event delivery to deliver_event function
      perf trace: Add ordered processing for --block option

 arch/x86/entry/common.c               | 36 ++++++++++++++++++++++++++++++++++--
 include/linux/perf_event.h            |  2 ++
 include/linux/sched.h                 |  2 ++
 include/linux/syscalls.h              |  2 ++
 include/uapi/linux/perf_event.h       |  3 ++-
 kernel/events/core.c                  | 40 ++++++++++++++++++++++++++++++++++++++--
 kernel/events/ring_buffer.c           |  4 +++-
 kernel/trace/trace_event_perf.c       |  4 ++++
 kernel/trace/trace_syscalls.c         | 28 ++++++++++++++++++++++++----
 tools/include/uapi/linux/perf_event.h |  3 ++-
 tools/perf/builtin-record.c           |  9 +++++++++
 tools/perf/builtin-trace.c            | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------
 tools/perf/perf.h                     |  1 +
 tools/perf/util/evsel.c               |  7 +++++++
 tools/perf/util/evsel.h               |  2 ++
 tools/perf/util/ordered-events.c      | 34 ++++++++++++++++++++++++++++++----
 tools/perf/util/ordered-events.h      |  3 +++
 tools/perf/util/parse-events.c        |  8 ++++++++
 tools/perf/util/parse-events.h        |  1 +
 tools/perf/util/parse-events.l        |  1 +
 20 files changed, 263 insertions(+), 24 deletions(-)