[Qemu-devel] [PATCH 1/2] migration/postcopy: reduce one operation to calculate fixup_start_addr

[Wei Yang <richardw.yang@linux.intel.com>]

Use the same way for run_end to calculate run_start, which saves one
operation.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
---
 migration/ram.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/migration/ram.c b/migration/ram.c
index 410e0f89fe..c4dc36e525 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2884,10 +2884,12 @@ static void postcopy_chunk_hostpages_pass(MigrationState *ms, bool unsent_pass,
         host_offset = run_start % host_ratio;
         if (host_offset) {
             do_fixup = true;
-            run_start -= host_offset;
-            fixup_start_addr = run_start;
-            /* For the next pass */
-            run_start = run_start + host_ratio;
+            fixup_start_addr = run_start - host_offset;
+            /*
+             * This host page has gone, the next loop iteration starts
+             * from after the fixup
+             */
+            run_start = fixup_start_addr + host_ratio;
         } else {
             /* Find the end of this run */
             unsigned long run_end;
-- 
2.17.1