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

[Leonardo Bras Soares Passos]

On Fri, May 26, 2023 at 5:09 AM Juan Quintela <quintela@redhat.com> wrote:
>
> 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.
>

Seems great to simplify stuff.
Thanks!
Leo