Re: [Qemu-devel] [PATCH v2 3/3] qmp/hmp: Add throttle ratio to query-migrate and info migrate

["Jason J. Herne" <jjherne@linux.vnet.ibm.com>]

On 06/02/2015 04:11 PM, Eric Blake wrote:
> On 06/02/2015 11:46 AM, Jason J. Herne wrote:
>> Report throttle ratio in info migrate and query-migrate responses when cpu
>> throttling is active.
>>
>> Signed-off-by: Jason J. Herne <jjherne@linux.vnet.ibm.com>
>> ---
>>   hmp.c                 | 5 +++++
>>   migration/migration.c | 5 +++++
>>   qapi-schema.json      | 3 ++-
>>   3 files changed, 12 insertions(+), 1 deletion(-)
>>
>> diff --git a/hmp.c b/hmp.c
>> index e17852d..cb3c137 100644
>> --- a/hmp.c
>> +++ b/hmp.c
>> @@ -229,6 +229,11 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
>>                          info->xbzrle_cache->overflow);
>>       }
>>
>> +    if (info->has_x_cpu_throttle_ratio) {
>> +        monitor_printf(mon, "cpu throttle ratio : %0.2f\n",
>
> s/ :/:/
>

Will fix, Thanks.

> How big or small can the ratio get? Is %g going to be nicer than %f if
> the ratio goes through a large range of possibilities?
>


You are correct in your interpretation below. So a ratio of 10.0 would be
90.9% throttled. A ratio of 100 would be 99% throttled. Given that, I think
we're ok with %f.

>> +++ b/qapi-schema.json
>> @@ -483,7 +483,8 @@
>>              '*total-time': 'int',
>>              '*expected-downtime': 'int',
>>              '*downtime': 'int',
>> -           '*setup-time': 'int'} }
>> +           '*setup-time': 'int',
>> +           '*x-cpu-throttle-ratio': 'number'} }
>
> Even though it is marked experimental, it is still worth documenting
> this parameter, and include mention of how to interpret it (0.0 means no
> throttling, 1.0 means 50% duty cycle, 2.0 means 33% duty cycle, right?).
> Documentation should mention '(since 2.4)'
>

Will fix.

-- 
-- Jason J. Herne (jjherne@linux.vnet.ibm.com)