[Qemu-devel] [PATCH 08/12] migration: do not flush_compressed_data at the end of each iteration

[guangrong . xiao]

From: Xiao Guangrong <address@hidden>

flush_compressed_data() needs to wait all compression threads to
finish their work, after that all threads are free until the
migration feed new request to them, reducing its call can improve
the throughput and use CPU resource more effectively

We do not need to flush all threads at the end of iteration, the
data can be kept locally until the memory block is changed

Signed-off-by: Xiao Guangrong <address@hidden>
---
 migration/ram.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/migration/ram.c b/migration/ram.c
index f9a8646520..0a38c1c61e 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1994,6 +1994,7 @@ static void ram_save_cleanup(void *opaque)
     }
 
     xbzrle_cleanup();
+    flush_compressed_data(*rsp);
     compress_threads_save_cleanup();
     ram_state_cleanup(rsp);
 }
@@ -2690,7 +2691,6 @@ static int ram_save_iterate(QEMUFile *f, void *opaque)
         }
         i++;
     }
-    flush_compressed_data(rs);
     rcu_read_unlock();
 
     /*
-- 
2.14.4