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

Juan Quintela posted 16 patches 2 years, 8 months ago
Maintainers: Daniel Henrique Barboza <danielhb413@gmail.com>, "Cédric Le Goater" <clg@kaod.org>, David Gibson <david@gibson.dropbear.id.au>, Greg Kurz <groug@kaod.org>, Harsh Prateek Bora <harshpb@linux.ibm.com>, Halil Pasic <pasic@linux.ibm.com>, Christian Borntraeger <borntraeger@linux.ibm.com>, Eric Farman <farman@linux.ibm.com>, Richard Henderson <richard.henderson@linaro.org>, David Hildenbrand <david@redhat.com>, Ilya Leoshkevich <iii@linux.ibm.com>, Thomas Huth <thuth@redhat.com>, Juan Quintela <quintela@redhat.com>, Peter Xu <peterx@redhat.com>, Leonardo Bras <leobras@redhat.com>, Stefan Hajnoczi <stefanha@redhat.com>, Fam Zheng <fam@euphon.net>, Eric Blake <eblake@redhat.com>, Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>, John Snow <jsnow@redhat.com>
[PATCH v2 04/16] qemu-file: Account for rate_limit usage on qemu_fflush()
Posted by Juan Quintela 2 years, 8 months ago 
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);
 }
 
-- 
2.40.1
Re: [PATCH v2 04/16] qemu-file: Account for rate_limit usage on qemu_fflush()
Posted by Leonardo Brás 2 years, 8 months ago 
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.

FWIW:
Reviewed-by: Leonardo Bras <leobras@redhat.com>
Re: [PATCH v2 04/16] qemu-file: Account for rate_limit usage on qemu_fflush()
Posted by Juan Quintela 2 years, 8 months ago 
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.
Re: [PATCH v2 04/16] qemu-file: Account for rate_limit usage on qemu_fflush()
Posted by Leonardo Bras Soares Passos 2 years, 8 months ago 
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

Patchew 2.1-devel-b67e4c2

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