[Qemu-devel] [PATCH 10/13] Only calculate expected_time for stage 2

[Juan Quintela]

ram_save_remaining() is an expensive operation when there is a lot of memory.
So we only call the function when we need it.

Signed-off-by: Juan Quintela <address@hidden>
---
 arch_init.c |   13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/arch_init.c b/arch_init.c
index f5fd1f5..643b696 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -314,7 +314,6 @@ int ram_save_live(QEMUFile *f, int stage, void *opaque)
     ram_addr_t addr;
     uint64_t bytes_transferred_last;
     double bwidth = 0;
-    uint64_t expected_time = 0;
     int ret;

     if (stage < 0) {
@@ -391,12 +390,16 @@ int ram_save_live(QEMUFile *f, int stage, void *opaque)

     qemu_put_be64(f, RAM_SAVE_FLAG_EOS);

-    expected_time = ram_save_remaining() * TARGET_PAGE_SIZE / bwidth;
+    if (stage == 2) {
+        uint64_t expected_time;
+        expected_time = ram_save_remaining() * TARGET_PAGE_SIZE / bwidth;

-    DPRINTF("ram_save_live: expected(" PRIu64 ") <= max(" PRIu64 ")?\n",
-            expected_time, migrate_max_downtime());
+        DPRINTF("ram_save_live: expected(" PRIu64 ") <= max(" PRIu64 ")?\n",
+                expected_time, migrate_max_downtime());

-    return (stage == 2) && (expected_time <= migrate_max_downtime());
+        return expected_time <= migrate_max_downtime();
+    }
+    return 0;
 }

 static inline void *host_from_stream_offset(QEMUFile *f,
-- 
1.7.10.4