Re: [Qemu-devel] [PATCH v3 6/8] migration: Make none operations into its own structure

[Juan Quintela]

"Dr. David Alan Gilbert" <address@hidden> wrote:
> * Juan Quintela (address@hidden) wrote:
>> It will be used later.
>
> 'none' is confusing - I think this is no-compression specifically -
> right?
> I'd be happy with something abbreviated like 'nocomp'

I don't care too much, I can change, but when you are setting the value
it gets:

micgration set-parameter compression none

That looks ok.

On the other hand, I can agree that I can call the functions nocomp.

Thanks, Juan.

>
>> Signed-off-by: Juan Quintela <address@hidden>
>> ---
>>  migration/ram.c | 54 ++++++++++++++++++++++++++++++++++++++++++++-----
>>  1 file changed, 49 insertions(+), 5 deletions(-)
>> 
>> diff --git a/migration/ram.c b/migration/ram.c
>> index 1ca9ba77b6..6679e4f213 100644
>> --- a/migration/ram.c
>> +++ b/migration/ram.c
>> @@ -700,6 +700,40 @@ typedef struct {
>>      QemuSemaphore sem_sync;
>>  } MultiFDRecvParams;
>>  
>> +typedef struct {
>> +    /* Prepare the send packet */
>> +    int (*send_prepare)(MultiFDSendParams *p, uint32_t used);
>> +    /* Write the send packet */
>> +    int (*send_write)(MultiFDSendParams *p, uint32_t used, Error **perr);
>> +    /* Read all pages */
>> +    int (*recv_pages)(MultiFDRecvParams *p, uint32_t used, Error **perr);
>> +} MultifdMethods;
>> +
>> +/* Multifd without compression */
>> +
>> +static int none_send_prepare(MultiFDSendParams *p, uint32_t used)
>> +{
>> +    p->next_packet_size = used * qemu_target_page_size();
>> +    return 0;
>> +}
>> +
>> +static int none_send_write(MultiFDSendParams *p, uint32_t used, Error 
>> **perr)
>> +{
>> +    return qio_channel_writev_all(p->c, p->pages->iov, used, perr);
>> +}
>> +
>> +static int none_recv_pages(MultiFDRecvParams *p, uint32_t used, Error 
>> **perr)
>> +{
>> +    return qio_channel_readv_all(p->c, p->pages->iov, used, perr);
>> +
>> +}
>> +
>> +MultifdMethods multifd_none_ops = {
>> +    .send_prepare = none_send_prepare,
>> +    .send_write = none_send_write,
>> +    .recv_pages = none_recv_pages
>> +};
>> +
>>  static int multifd_send_initial_packet(MultiFDSendParams *p, Error **errp)
>>  {
>>      MultiFDInit_t msg;
>> @@ -904,6 +938,8 @@ struct {
>>      uint64_t packet_num;
>>      /* send channels ready */
>>      QemuSemaphore channels_ready;
>> +    /* multifd ops */
>> +    MultifdMethods *ops;
>>  } *multifd_send_state;
>>  
>>  /*
>> @@ -1093,6 +1129,8 @@ static void *multifd_send_thread(void *opaque)
>>      /* initial packet */
>>      p->num_packets = 1;
>>  
>> +    multifd_send_state->ops = &multifd_none_ops;
>> +
>
> I agree with Wei Yang that is a bad idea; that should be done once
> before the first thread is started.
>
> Dave
>
>>      while (true) {
>>          qemu_sem_wait(&p->sem);
>>          qemu_mutex_lock(&p->mutex);
>> @@ -1102,7 +1140,12 @@ static void *multifd_send_thread(void *opaque)
>>              uint64_t packet_num = p->packet_num;
>>              uint32_t flags = p->flags;
>>  
>> -            p->next_packet_size = used * qemu_target_page_size();
>> +            if (used) {
>> +                ret = multifd_send_state->ops->send_prepare(p, used);
>> +                if (ret != 0) {
>> +                    break;
>> +                }
>> +            }
>>              multifd_send_fill_packet(p);
>>              p->flags = 0;
>>              p->num_packets++;
>> @@ -1120,8 +1163,7 @@ static void *multifd_send_thread(void *opaque)
>>              }
>>  
>>              if (used) {
>> -                ret = qio_channel_writev_all(p->c, p->pages->iov,
>> -                                             used, &local_err);
>> +                ret = multifd_send_state->ops->send_write(p, used, 
>> &local_err);
>>                  if (ret != 0) {
>>                      break;
>>                  }
>> @@ -1223,6 +1265,8 @@ struct {
>>      QemuSemaphore sem_sync;
>>      /* global number of generated multifd packets */
>>      uint64_t packet_num;
>> +    /* multifd ops */
>> +    MultifdMethods *ops;
>>  } *multifd_recv_state;
>>  
>>  static void multifd_recv_terminate_threads(Error *err)
>> @@ -1324,6 +1368,7 @@ static void *multifd_recv_thread(void *opaque)
>>      trace_multifd_recv_thread_start(p->id);
>>      rcu_register_thread();
>>  
>> +    multifd_recv_state->ops = &multifd_none_ops;
>>      while (true) {
>>          uint32_t used;
>>          uint32_t flags;
>> @@ -1353,8 +1398,7 @@ static void *multifd_recv_thread(void *opaque)
>>          qemu_mutex_unlock(&p->mutex);
>>  
>>          if (used) {
>> -            ret = qio_channel_readv_all(p->c, p->pages->iov,
>> -                                        used, &local_err);
>> +            ret = multifd_recv_state->ops->recv_pages(p, used, &local_err);
>>              if (ret != 0) {
>>                  break;
>>              }
>> -- 
>> 2.21.0
>> 
> --
> Dr. David Alan Gilbert / address@hidden / Manchester, UK