[Qemu-commits] [qemu/qemu] d6b76d: trace: use static event ID mapping in simpletrace....

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/qemu/qemu
  Commit: d6b76d68054b81943648ab0af2f9634ae946854b
      
https://github.com/qemu/qemu/commit/d6b76d68054b81943648ab0af2f9634ae946854b
  Author: Stefan Hajnoczi <address@hidden>
  Date:   2017-08-15 (Tue, 15 Aug 2017)

  Changed paths:
    M scripts/tracetool/format/simpletrace_stap.py

  Log Message:
  -----------
  trace: use static event ID mapping in simpletrace.stp

This is a partial revert of commit
7f1b588f20d027730676e627713ae3bbf6baab04 ("trace: emit name <-> ID
mapping in simpletrace header"), which broke the SystemTap flight
recorder because event mapping records may not be present in the ring
buffer when the trace is analyzed.  This means simpletrace.py
--no-header does not know the event ID mapping needed to pretty-print
the trace.

Instead of numbering events dynamically, use a static event ID mapping
as dictated by the event order in the trace-events-all file.

The simpletrace.py script also uses trace-events-all so the next patch
will fix the simpletrace.py --no-header option to take advantage of this
knowledge.

Cc: Daniel P. Berrange <address@hidden>
Signed-off-by: Stefan Hajnoczi <address@hidden>
Reviewed-by: Daniel P. Berrange <address@hidden>
Message-id: address@hidden
Signed-off-by: Stefan Hajnoczi <address@hidden>


  Commit: 840d8351774664d01c328d31ed33b0e2d85c866e
      
https://github.com/qemu/qemu/commit/840d8351774664d01c328d31ed33b0e2d85c866e
  Author: Stefan Hajnoczi <address@hidden>
  Date:   2017-08-15 (Tue, 15 Aug 2017)

  Changed paths:
    M scripts/simpletrace.py

  Log Message:
  -----------
  simpletrace: fix flight recorder --no-header option

The simpletrace.py script can pretty-print flight recorder ring buffers.
These are not full simpletrace binary trace files but just the end of a
trace file.  There is no header and the event ID mapping information is
often unavailable since the ring buffer may have filled up and discarded
event ID mapping records.

The simpletrace.stp script that generates ring buffer traces uses the
same trace-events-all input file as simpletrace.py.  Therefore both
scripts have the same global ordering of trace events.  A dynamic event
ID mapping isn't necessary: just use the trace-events-all file as the
reference for how event IDs are numbered.

It is now possible to analyze simpletrace.stp ring buffers again using:

  $ ./simpletrace.py trace-events-all path/to/ring-buffer

Signed-off-by: Stefan Hajnoczi <address@hidden>
Reviewed-by: Daniel P. Berrange <address@hidden>
Message-id: address@hidden
Signed-off-by: Stefan Hajnoczi <address@hidden>


  Commit: 81a6a2d48a6c7543a03265bcc5c5bbb0d929d894
      
https://github.com/qemu/qemu/commit/81a6a2d48a6c7543a03265bcc5c5bbb0d929d894
  Author: Peter Maydell <address@hidden>
  Date:   2017-08-15 (Tue, 15 Aug 2017)

  Changed paths:
    M scripts/simpletrace.py
    M scripts/tracetool/format/simpletrace_stap.py

  Log Message:
  -----------
  Merge remote-tracking branch 'remotes/stefanha/tags/tracing-pull-request' 
into staging

# gpg: Signature made Tue 15 Aug 2017 14:27:34 BST
# gpg:                using RSA key 0x9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <address@hidden>"
# gpg:                 aka "Stefan Hajnoczi <address@hidden>"
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha/tags/tracing-pull-request:
  simpletrace: fix flight recorder --no-header option
  trace: use static event ID mapping in simpletrace.stp

Signed-off-by: Peter Maydell <address@hidden>


Compare: https://github.com/qemu/qemu/compare/c4a6a8887c1b...81a6a2d48a6c