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authorPeter Lieven <pl@kamp.de>2017-09-26 12:33:16 +0200
committerDr. David Alan Gilbert <dgilbert@redhat.com>2017-09-27 11:27:14 +0100
commit9ac78b6171bec47083a9b6ce88dc1f114caea2f9 (patch)
tree5a7329bb5f0bd8c1f1fa9a02a960326dd992b44e
parent31bc1d8481af414cfa2857f905e40f7d8e6d5b2e (diff)
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migration: disable auto-converge during bulk block migration
auto-converge and block migration currently do not play well together. During block migration the auto-converge logic detects that ram migration makes no progress and thus throttles down the vm until it nearly stalls completely. Avoid this by disabling the throttling logic during the bulk phase of the block migration. Cc: qemu-stable@nongnu.org Signed-off-by: Peter Lieven <pl@kamp.de> Message-Id: <1506421996-12513-1-git-send-email-pl@kamp.de> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
-rw-r--r--migration/block.c5
-rw-r--r--migration/block.h7
-rw-r--r--migration/ram.c6
3 files changed, 17 insertions, 1 deletions
diff --git a/migration/block.c b/migration/block.c
index 9171f60..606ad4d 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -161,6 +161,11 @@ int blk_mig_active(void)
return !QSIMPLEQ_EMPTY(&block_mig_state.bmds_list);
}
+int blk_mig_bulk_active(void)
+{
+ return blk_mig_active() && !block_mig_state.bulk_completed;
+}
+
uint64_t blk_mig_bytes_transferred(void)
{
BlkMigDevState *bmds;
diff --git a/migration/block.h b/migration/block.h
index 22ebe94..3178609 100644
--- a/migration/block.h
+++ b/migration/block.h
@@ -16,6 +16,7 @@
#ifdef CONFIG_LIVE_BLOCK_MIGRATION
int blk_mig_active(void);
+int blk_mig_bulk_active(void);
uint64_t blk_mig_bytes_transferred(void);
uint64_t blk_mig_bytes_remaining(void);
uint64_t blk_mig_bytes_total(void);
@@ -25,6 +26,12 @@ static inline int blk_mig_active(void)
{
return false;
}
+
+static inline int blk_mig_bulk_active(void)
+{
+ return false;
+}
+
static inline uint64_t blk_mig_bytes_transferred(void)
{
return 0;
diff --git a/migration/ram.c b/migration/ram.c
index 88ca69e..b83f897 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -46,6 +46,7 @@
#include "exec/ram_addr.h"
#include "qemu/rcu_queue.h"
#include "migration/colo.h"
+#include "migration/block.h"
/***********************************************************/
/* ram save/restore */
@@ -825,7 +826,10 @@ static void migration_bitmap_sync(RAMState *rs)
/ (end_time - rs->time_last_bitmap_sync);
bytes_xfer_now = ram_counters.transferred;
- if (migrate_auto_converge()) {
+ /* During block migration the auto-converge logic incorrectly detects
+ * that ram migration makes no progress. Avoid this by disabling the
+ * throttling logic during the bulk phase of block migration. */
+ if (migrate_auto_converge() && !blk_mig_bulk_active()) {
/* The following detection logic can be refined later. For now:
Check to see if the dirtied bytes is 50% more than the approx.
amount of bytes that just got transferred since the last time we