block migration: Increase dirty chunk size to 1M

4K is too small for efficiently saving and restoring multi-GB block
devices.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

diff --git a/block.h b/block.h
index 35137122772015c003bf46d330b3e2fc6f560ef9..4a8b6283e41dd034cc0b80451f1b5a3b7ac33d4e 100644 (file)
--- a/block.h
+++ b/block.h
@@ -192,7 +192,7 @@ int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
                       int64_t pos, int size);
 
-#define BDRV_SECTORS_PER_DIRTY_CHUNK 8
+#define BDRV_SECTORS_PER_DIRTY_CHUNK 2048
 
 void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable);
 int bdrv_get_dirty(BlockDriverState *bs, int64_t sector);