Re: [Qemu-devel] [PATCH v5 00/10] trace-state: make the behaviour of "disable" consistent across all backends

[Stefan Hajnoczi <stefanha@gmail.com>]

On Tue, Jun 28, 2011 at 06:52:55PM +0200, Lluís wrote:
> This patch defines the "disable" trace event state to always use the "nop"
> backend.
> 
> As a side-effect, all events are now enabled (without "disable") by default, as
> all backends (except "stderr") have programmatic support for dynamically
> (de)activating each trace event.
> 
> In order to make this true, the "simple" backend now has a "-trace
> events=<file>" argument to let the user select which events must be enabled from
> the very beginning.
> 
> NOTES:
> * Parsing of -trace arguments is not done in the OS-specific frontends.
> 
> Signed-off-by: Lluís Vilanova <vilanova@ac.upc.edu>
> ---
> 
> Changes in v5:
> 
> * Fix a variable name typo in configure.
> * Rebase on qemu.git/master (c24a9c6ef946ec1b5b280061d4f7b579aaac6707).
> 
> Changes in v4:
> 
> * Fix a couple of minor errors.
> 
> Changes in v3:
> 
> * Rebase on qemu.git/master (642cfd4d31241c0fc65c520cb1e703659af66236).
> * Remove already-merged patches.
> * Remove code styling patches.
> * Generalize programmatic interface for trace event state control.
> 
> Changes in v2:
> 
> * Documentation fixes.
> * Seggregate whitespace/indentation changes.
> * Minor code beautifications.
> * Make all -trace suboptions explicit.
> * Fix minor comments from Stefan.
> * Minor trace-events format fixes.
> * Integrate changes from Fabien.
> * Rebase on qemu.git/master (c8f930c0eeb696d638f4d4bf654e955fa44ff40f).
> 
> Lluís Vilanova (10):
>       trace: move backend-specific code into the trace/ directory
>       trace: avoid conditional code compilation during option parsing
>       trace: generalize the "property" concept in the trace-events file
>       trace-state: separate trace event control and query routines from the simple backend
>       trace-state: always compile support for controlling and querying trace event states
>       trace-state: add "-trace events" argument to control initial state
>       trace-state: always use the "nop" backend on events with the "disable" keyword
>       trace-state: [simple] disable all trace points by default
>       trace-state: [stderr] add support for dynamically enabling/disabling events
>       trace: enable all events
> 
> 
>  .gitignore        |    2 
>  Makefile          |    1 
>  Makefile.objs     |    5 
>  configure         |    7 +
>  docs/tracing.txt  |   64 +++---
>  hmp-commands.hx   |    9 +
>  monitor.c         |   19 +-
>  qemu-config.c     |    7 -
>  qemu-options.hx   |   26 ++
>  scripts/tracetool |  116 +++++------
>  simpletrace.c     |  355 ---------------------------------
>  simpletrace.h     |   48 ----
>  trace-events      |  569 ++++++++++++++++++++++++++---------------------------
>  trace/control.c   |   66 ++++++
>  trace/control.h   |   16 +
>  trace/simple.c    |  332 +++++++++++++++++++++++++++++++
>  trace/simple.h    |   46 ++++
>  trace/stderr.h    |   11 +
>  vl.c              |   21 +-
>  19 files changed, 914 insertions(+), 806 deletions(-)
>  delete mode 100644 simpletrace.c
>  delete mode 100644 simpletrace.h
>  create mode 100644 trace/control.c
>  create mode 100644 trace/control.h
>  create mode 100644 trace/simple.c
>  create mode 100644 trace/simple.h
>  create mode 100644 trace/stderr.h

Nice!  Now both stderr and simple are unified in terms of user
interface.  -trace events=<file> can be used to set the enabled trace
events on startup.

I did leave some comments, mainly #ifdef reduction.  But let's merge the
next version.

Stefan