[Qemu-devel] Re: [Tracing][RFC] QMP interface to toggle state of a trace-event

[Prerna Saxena <prerna@linux.vnet.ibm.com>]

Thanks for the review!

On 10/21/2010 12:53 AM, Luiz Capitulino wrote:
> On Wed, 20 Oct 2010 15:28:49 +0530
> Prerna Saxena<prerna@linux.vnet.ibm.com>  wrote:
>
>> QMP command trace-event to toggle state of a trace-event.
>>   Illustration :
>>   ->  { "execute": "trace-event", "arguments": { "name": "qemu_malloc", "option": true} }
>>   <- { "return": {} }
>>
>> Posting this as an RFC for now. I'll post the final version as a part of
>>   the cumulative QMP patchset for tracing ( including patches for query-*
>> commands posted earlier :
>> http://lists.gnu.org/archive/html/qemu-devel/2010-10/msg01232.html )
>>
>> Signed-off-by: Prerna Saxena<prerna@linux.vnet.ibm.com>
>> ---
>>   hmp-commands.hx |    2 +-
>>   monitor.c       |   43 +++++++++++++++++++++++++++++++++++++------
>>   qmp-commands.hx |   32 ++++++++++++++++++++++++++++++++
>>   3 files changed, 70 insertions(+), 7 deletions(-)
>> diff --git a/qmp-commands.hx b/qmp-commands.hx
>> index bc79b55..7613d73 100644
>> --- a/qmp-commands.hx
>> +++ b/qmp-commands.hx
>> @@ -761,6 +761,38 @@ Example:
>>
>>   Note: This command must be issued before issuing any other command.
>>
>> +EQMP
>> +
>> +    {
>> +        .name       = "trace-event",
>> +        .args_type  = "name:s,option:b",
>> +        .params     = "name on|off",
>> +        .help       = "changes state of a specific trace event",
>> +        .user_print = monitor_user_noop,
>> +        .mhandler.cmd_new = do_change_trace_event_state_qmp,
>> +    },
>> +
>> +SQMP
>> +trace-event
>> +-----------
>> +
>> +Change state of a trace-event.
>> +
>> +Arguments:
>> +
>> +- "name": name of trace-event (json-string)
>> +- "option": new state for the trace-event (json-bool)
>
> This should be called 'enabled'.
>

I agree, 'enabled' is less ambiguous. Will change in the next patchset.


> I think you should submit a new series containing only the proposed
> interfaces documentation (one patch per interface) and the intro email
> should describe the use cases the proposed interfaces are supposed to
> address.

I'll send out the new documentation patchset series shortly.

>> +
>> +Example:
>> +
>> +->  { "execute": "trace-event", "arguments": { "name": "ABC", "option":false } }
>> +<- { "return": {} }
>> +
>> +Notes:
>> +
>> +(1) The 'query-trace-events' command should be used to check the new state
>> +    of the trace-event.
>> +
>>   3. Query Commands
>>   =================
>>
>


-- 
Prerna Saxena

Linux Technology Centre,
IBM Systems and Technology Lab,
Bangalore, India