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Re: [Qemu-devel] [PATCH v7 08/13] trace-state: always compile support fo
From: |
Stefan Hajnoczi |
Subject: |
Re: [Qemu-devel] [PATCH v7 08/13] trace-state: always compile support for controlling and querying trace event states |
Date: |
Wed, 31 Aug 2011 11:10:45 +0100 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
On Thu, Aug 25, 2011 at 09:18:24PM +0200, Lluís wrote:
> The current interface is generic for this small set of operations, and thus
> other backends can easily modify the "trace/control.c" file to add their own
> implementation.
>
> Signed-off-by: Lluís Vilanova <address@hidden>
> ---
> docs/tracing.txt | 39 +++++++++++++++++++++------------------
> hmp-commands.hx | 7 +++++--
> monitor.c | 9 +++++----
> 3 files changed, 31 insertions(+), 24 deletions(-)
>
> diff --git a/docs/tracing.txt b/docs/tracing.txt
> index 1ad106a..017ff59 100644
> --- a/docs/tracing.txt
> +++ b/docs/tracing.txt
> @@ -108,6 +108,27 @@ portability macros, ensure they are preceded and
> followed by double quotes:
> of trace events. Marking trace events disabled by default saves the user
> from having to manually disable noisy trace events.
>
> +== Generic interface and monitor commands ==
> +
> +You can programmatically query and control the dynamic state of trace events
> +through a backend-agnostic interface:
> +
> +* trace_print_events
> +
> +* trace_event_set_state
> +
> +Note that some of the backends do not provide and implementation for this
s/and/an/
> +interface, in which case QEMU will just print a warning.
> +
> +This functionality is also provided through monitor commands:
> +
> +* info trace-events
> + View available trace events and their state. State 1 means enabled, state > 0
> + means disabled.
> +
> +* trace-event NAME on|off
> + Enable/disable a given trace event.
> +
> == Trace backends ==
>
> The "tracetool" script automates tedious trace event code generation and also
> @@ -157,27 +178,9 @@ unless you have specific needs for more advanced
> backends.
> flushed and emptied. This means the 'info trace' will display few or no
> entries if the buffer has just been flushed.
>
> -* info trace-events
> - View available trace events and their state. State 1 means enabled, state > 0
> - means disabled.
> -
> -* trace-event NAME on|off
> - Enable/disable a given trace event.
> -
> * trace-file on|off|flush|set <path>
> Enable/disable/flush the trace file or set the trace file name.
>
> -==== Enabling/disabling trace events programmatically ====
> -
> -The st_change_trace_event_state() function can be used to enable or disable
> trace
> -events at runtime inside QEMU:
> -
> - #include "trace.h"
> -
> - st_change_trace_event_state("virtio_irq", true); /* enable */
> - [...]
> - st_change_trace_event_state("virtio_irq", false); /* disable */
> -
Please update and move this example to where trace_event_set_state() is
documented. Having an example makes it clear what this function does.
Stefan
- [Qemu-devel] [PATCH v7 04/13] trace: move backend-specific code into the trace/ directory, (continued)
- [Qemu-devel] [PATCH v7 04/13] trace: move backend-specific code into the trace/ directory, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 05/13] trace: avoid conditional code compilation during option parsing, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 06/13] trace: generalize the "property" concept in the trace-events file, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 11/13] trace-state: [simple] disable all trace points by default, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 12/13] trace-state: [stderr] add support for dynamically enabling/disabling events, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 13/13] trace: enable all events, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 08/13] trace-state: always compile support for controlling and querying trace event states, Lluís, 2011/08/25
- Re: [Qemu-devel] [PATCH v7 08/13] trace-state: always compile support for controlling and querying trace event states,
Stefan Hajnoczi <=
- [Qemu-devel] [PATCH v7 09/13] trace-state: add "-trace events" argument to control initial state, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 07/13] trace-state: separate trace event control and query routines from the simple backend, Lluís, 2011/08/25
- [Qemu-devel] [PATCH v7 10/13] trace-state: always use the "nop" backend on events with the "disable" keyword, Lluís, 2011/08/25
- Re: [Qemu-devel] [PATCH v7 00/13] trace-state: make the behaviour of "disable" consistent across all backends, Stefan Hajnoczi, 2011/08/31
- Re: [Qemu-devel] [PATCH v7 00/13] trace-state: make the behaviour of "disable" consistent across all backends, Stefan Hajnoczi, 2011/08/31