Re: [PATCH v2 04/16] qemu-file: Account for rate_limit usage on qemu_fflush()

[Juan Quintela <quintela@redhat.com>]

Leonardo Brás <leobras@redhat.com> wrote:
> On Mon, 2023-05-15 at 21:56 +0200, Juan Quintela wrote:
>> That is the moment we know we have transferred something.
>> 
>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>> Reviewed-by: Cédric Le Goater <clg@kaod.org>
>> ---
>>  migration/qemu-file.c | 7 +++----
>>  1 file changed, 3 insertions(+), 4 deletions(-)
>> 
>> diff --git a/migration/qemu-file.c b/migration/qemu-file.c
>> index 4bc875b452..956bd2a580 100644
>> --- a/migration/qemu-file.c
>> +++ b/migration/qemu-file.c
>> @@ -302,7 +302,9 @@ void qemu_fflush(QEMUFile *f)
>>                                     &local_error) < 0) {
>>              qemu_file_set_error_obj(f, -EIO, local_error);
>>          } else {
>> -            f->total_transferred += iov_size(f->iov, f->iovcnt);
>> +            uint64_t size = iov_size(f->iov, f->iovcnt);
>> +            qemu_file_acct_rate_limit(f, size);
>> +            f->total_transferred += size;
>>          }
>>  
>>          qemu_iovec_release_ram(f);
>> @@ -519,7 +521,6 @@ void qemu_put_buffer_async(QEMUFile *f, const uint8_t *buf, size_t size,
>>          return;
>>      }
>>  
>> -    f->rate_limit_used += size;
>>      add_to_iovec(f, buf, size, may_free);
>>  }
>>  
>> @@ -537,7 +538,6 @@ void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, size_t size)
>>              l = size;
>>          }
>>          memcpy(f->buf + f->buf_index, buf, l);
>> -        f->rate_limit_used += l;
>>          add_buf_to_iovec(f, l);
>>          if (qemu_file_get_error(f)) {
>>              break;
>> @@ -554,7 +554,6 @@ void qemu_put_byte(QEMUFile *f, int v)
>>      }
>>  
>>      f->buf[f->buf_index] = v;
>> -    f->rate_limit_used++;
>>      add_buf_to_iovec(f, 1);
>>  }
>>  
>
> If we are counting transferred data at fflush, it makes sense to increase rate-
> limit accounting at the same place. It may be less granular, but is more
> efficient.

Yeap, the whole point is that in my next series, rate_limit_used
dissapear, we just use transferred for both things(*).

Later, Juan.

*: It is a bit more complicated than that, but we go from three counters
 to a single counter.