[Qemu-devel] [PATCH v7 0/3] Simpletrace v2: Support multiple args, strings.

[Harsh Prateek Bora <harsh@linux.vnet.ibm.com>]

Existing simpletrace backend allows to trace at max 6 args and does not
support strings. This newer tracelog format gets rid of fixed size records
and therefore allows to trace variable number of args including strings.

Sample trace:
v9fs_version 0.000 tag=0xffff id=0x64 msize=0x2000 version=9P2000.L
v9fs_version_return 6.705 tag=0xffff id=0x64 msize=0x2000 version=9P2000.L
v9fs_attach 174.467 tag=0x1 id=0x68 fid=0x0 afid=0xffffffffffffffff
uname=nobody aname=
v9fs_attach_return 4720.454 tag=0x1 id=0x68 type=0xffffffffffffff80
version=0x4f2a4dd0  path=0x220ea6

v7:
- Introduced clear_buffer_range to rest buffer range after consuming record.
- Introduced cap on string length using MAX_TRACE_STRLEN (currently set to 512)
  to avoid calculating wrong length when string length is > sizeof(uint32_t).
- Reverted idx refresh back to inside while-lipp in writeout_thread.

v6:
- Corrected flush condition and reverted un-necessary check in get_trace_record
- moved idx refresh out of while-loop in writeout_thread, see comments in code.

v5:
- Addressed Stefan's review comments on v4 series.
- Inroduced code to handle corrupted records due to racing tracers.

v4:
- removed unused safe_strlen interface (missed in v3).

v3:
- Addressed Stefan's review comments on v2 series

v2:
- moved elimination of st_print_trace to 1/3 patch
- use sizeof(TraceRecord) for #define ST_REC_HDR_LEN

v1:
- Simpletrace v2 for the new (pythonized) tracetool

Harsh Prateek Bora (3):
  monitor: remove unused do_info_trace
  Simpletrace v2: Support multiple arguments, strings.
  Update simpletrace.py for new log format

 monitor.c                           |   16 --
 scripts/simpletrace.py              |  116 +++++++++------
 scripts/tracetool/backend/simple.py |   84 ++++++++---
 trace/simple.c                      |  274 +++++++++++++++++++++--------------
 trace/simple.h                      |   40 ++++-
 5 files changed, 335 insertions(+), 195 deletions(-)

-- 
1.7.10.4