Re: [Qemu-devel] [PATCH v12 10/21] migration: Create multipage support

[Juan Quintela <quintela@redhat.com>]

"Dr. David Alan Gilbert" <dgilbert@redhat.com> wrote:
> * Juan Quintela (quintela@redhat.com) wrote:
>> We only create/destry the page list here.  We will use it later.
>> 
>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>> ---
>>  migration/ram.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 56 insertions(+)
>> 
>> diff --git a/migration/ram.c b/migration/ram.c
>> index ffefa73099..b19300992e 100644
>> --- a/migration/ram.c
>> +++ b/migration/ram.c
>> @@ -412,6 +412,20 @@ typedef struct {
>>      uint8_t id;
>>  } __attribute__((packed)) MultiFDInit_t;
>>  
>> +typedef struct {
>> +    /* number of used pages */
>> +    uint32_t used;
>> +    /* number of allocated pages */
>> +    uint32_t allocated;
>> +    /* global number of generated multifd packets */
>> +    uint32_t seq;
>
> Is that sufficiently large?
> Consider a 40Gbps link; that's ~4GByte/second,
> so if each packet is a 4K page, that's just over one hour at
> that link speed;  that's a long migration on a fast link, but
> it's not impossible is it - and what happens when it wraps?

Nothing really, it is just a counter that is used for traces.

Later, Juan.