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envelope-from=farosas@suse.de; helo=smtp-out1.suse.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: qemu development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Peter Xu writes: > COLO caches all device states in a buffer channel `fb'. Flush it right > before pushing the buffer to make sure everything needed will be flushed, > add a comment explaning it. > > Signed-off-by: Peter Xu > --- > migration/colo.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/migration/colo.c b/migration/colo.c > index f92803dd29..e2307f1907 100644 > --- a/migration/colo.c > +++ b/migration/colo.c > @@ -472,8 +472,6 @@ static int colo_do_checkpoint_transaction(MigrationState *s, > qemu_savevm_state_complete_precopy_iterable(s->to_dst_file, false); > qemu_put_byte(s->to_dst_file, QEMU_VM_EOF); > > - qemu_fflush(fb); > - > /* > * We need the size of the VMstate data in Secondary side, > * With which we can decide how much data should be read. > @@ -484,6 +482,8 @@ static int colo_do_checkpoint_transaction(MigrationState *s, > goto out; > } > > + /* Flush to make sure everything lands bioc->data */ > + qemu_fflush(fb); > qemu_put_buffer(s->to_dst_file, bioc->data, bioc->usage); > ret = qemu_fflush(s->to_dst_file); Reviewed-by: Fabiano Rosas Wait, aren't we wasting a memcpy here? Isn't this the same, but without the copy of bioc->data to s->to_dst_file->buf: qemu_fflush(fb); // ensure bioc->data is populated qemu_fflush(s->to_dst_file); // send buffered data from migration stream qemu_put_buffer_async(s->to_dst_file, bioc->data, ...); // point s->to_dst_file->iov to bioc->data qemu_fflush(s->to_dst_file); // send s->to_dst_file->iov contents > if (ret < 0) {