Re: [Qemu-devel] [RFC PATCH v2 08/12] mc: core logic

["Michael R. Hines" <mrhines@linux.vnet.ibm.com>]

On 02/19/2014 09:07 AM, Li Guang wrote:
> Hi,
> mrhines@linux.vnet.ibm.com wrote:
>> From: "Michael R. Hines"<mrhines@us.ibm.com>
>>
>> This implements the core logic,
>> all described in the first patch (docs/mc.txt).
>>
>> Signed-off-by: Michael R. Hines<mrhines@us.ibm.com>
>> ---
>>   migration-checkpoint.c | 1565 
>> ++++++++++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 1565 insertions(+)
>>   create mode 100644 migration-checkpoint.c
>>
>>
> [big snip] ...
>
>> +
>> +/*
>> + * Stop the VM, generate the micro checkpoint,
>> + * but save the dirty memory into staging memory until
>> + * we can re-activate the VM as soon as possible.
>> + */
>> +static int capture_checkpoint(MCParams *mc, MigrationState *s)
>> +{
>> +    MCCopyset *copyset;
>> +    int idx, ret = 0;
>> +    uint64_t start, stop, copies = 0;
>> +    int64_t start_time;
>> +
>> +    mc->total_copies = 0;
>> +    qemu_mutex_lock_iothread();
>> +    vm_stop_force_state(RUN_STATE_CHECKPOINT_VM);
>> +    start = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
>> +
>> +    /*
>> +     * If buffering is enabled, insert a Qdisc plug here
>> +     * to hold packets for the *next* MC, (not this one,
>> +     * the packets for this one have already been plugged
>> +     * and will be released after the MC has been transmitted.
>> +     */
>> +    mc_start_buffer();
>
> actually, I have a special request,
> if QEMU started without netdev,
> then don't bother me by Qdisc for network buffering. :-)
>
> Thanks!
>

That ability is already available in the patchset.
It is called "mc-net-disable" capability. (See the wiki or docs/mc.txt).

Did you try it?

- Michael