Re: [Qemu-devel] [PATCH 4/4] trace: enable trace events in qemu-img

["Denis V. Lunev" <den@openvz.org>]

On 05/31/2016 03:50 PM, Eric Blake wrote:
> On 05/31/2016 04:07 AM, Denis V. Lunev wrote:
>> The command will work this way:
>>      qemu-img create --trace qcow2* -f qcow2 1.img 64G
>>
>> Signed-off-by: Denis V. Lunev <den@openvz.org>
>> Suggested by: Daniel P. Berrange <berrange@redhat.com>
>> CC: Eric Blake <eblake@redhat.com>
>> CC: Paolo Bonzini <pbonzini@redhat.com>
>> CC: Stefan Hajnoczi <stefanha@redhat.com>
>> CC: Kevin Wolf <kwolf@redhat.com>
>> ---
>>   qemu-img.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
>>   1 file changed, 96 insertions(+), 1 deletion(-)
> Missing man page additions.
>
>
>> @@ -155,7 +157,12 @@ static void QEMU_NORETURN help(void)
>>              "Parameters to compare subcommand:\n"
>>              "  '-f' first image format\n"
>>              "  '-F' second image format\n"
>> -           "  '-s' run in Strict mode - fail on different image size or sector allocation\n";
>> +           "  '-s' run in Strict mode - fail on different image size or sector allocation\n"
>> +           "\n"
>> +           "General purpose options:\n"
>> +           "  -R, --trace [[enable=]<pattern>][,events=<file>][,file=<file>]\n"
>> +           "       specify tracing options\n"
>> +           "       see qemu(1) man page for full description\n";
> Why -R? Because -T is already in use by rebase and compare?  I'd almost
> rather have _just_ --trace with no short option, than to pick yet
> another letter, but you might want to wait for other opinions first.
>
> I'd list general parameters before sub-command parameters.  I'd also
> update the synopsis:
>
> qemu-img [general options] command [command options]
>
Actually me too. I have though about this before submission but stick to
current approach following Fam's locking games. This would make the code 
MUCH better.

Fam, may be this also makes sense for your games with locking...

Den