[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH] migration/throttle: Add throttle-trig-thres migration parame
Re: [PATCH] migration/throttle: Add throttle-trig-thres migration parameter
Mon, 24 Feb 2020 09:11:43 +0800
Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1
On 2020/2/21 22:14, Eric Blake wrote:
> On 2/20/20 8:57 PM, Keqian Zhu wrote:
>> Currently, if the bytes_dirty_period is more than the 50% of
>> bytes_xfer_period, we start or increase throttling.
>> If we make this percentage higher, then we can tolerate higher
>> dirty rate during migration, which means less impact on guest.
>> The side effect of higher percentage is longer migration time.
>> We can configure this parameter to switch between migration time
>> firt or guest performance first. The default value is 50.
>> Signed-off-by: Keqian Zhu <address@hidden>
>> Cc: Juan Quintela <address@hidden>
>> Cc: "Dr. David Alan Gilbert" <address@hidden>
>> Cc: Eric Blake <address@hidden>
>> Cc: Markus Armbruster <address@hidden>
>> +++ b/qapi/migration.json
>> @@ -524,6 +524,10 @@
>> # compression, so set the decompress-threads to the
>> number about 1/4
>> # of compress-threads is adequate.
>> +# @throttle-trig-thres: The ratio of bytes_dirty_period and
>> bytes_xfer_period to
>> +# trigger throttling. It is expressed as percentage.
>> +# default value is 50. (Since 5.0)
> Abbreviating feels odd; can you please spell this out as
OK, I will use full name in v2.
> Can the threshold exceed 100%?
If the threshold exceed 100% and the dirty rate is between 100% and threshold,
will not be started, so the migration will not converge and last an uncertain
time until the workload
in guest is down by itself. So I think that the threshold exceed 100% maybe not