[Qemu-devel] Re: [PATCH 3/6] trace-state: always use the "nop" backend on events with the "disable" keyword

[Stefan Hajnoczi]

On Mon, Apr 4, 2011 at 10:49 PM, Lluís <address@hidden> wrote:
> Any event with the keyword/property "disable" generates an empty trace event
> using the "nop" backend, regardless of the current backend.
>
> Signed-off-by: Lluís Vilanova <address@hidden>
> ---
>  docs/tracing.txt  |    3 +++
>  scripts/tracetool |   15 ++-------------
>  2 files changed, 5 insertions(+), 13 deletions(-)
>
> diff --git a/docs/tracing.txt b/docs/tracing.txt
> index 5dbd3c0..49e030e 100644
> --- a/docs/tracing.txt
> +++ b/docs/tracing.txt
> @@ -126,6 +126,9 @@ The "nop" backend generates empty trace event functions 
> so that the compiler
>  can optimize out trace events completely.  This is the default and imposes no
>  performance penalty.
>
> +Note that regardless of the selected trace backend, events with the "disable"
> +property will be generated with the "nop" backend.
> +
>  === Stderr ===
>
>  The "stderr" backend sends trace events directly to standard error.  This

Please also fix up docs/tracing.txt:
2. Enable trace events you are interested in:

    $EDITOR trace-events  # remove "disable" from events you want

The comment is now obsolete.

Stefan