[PATCH v7 1/2] Reset the auto-converge counter at every checkpoint.

[Rao, Lei]

From: "Rao, Lei" <lei.rao@intel.com>

if we don't reset the auto-converge counter,
it will continue to run with COLO running,
and eventually the system will hang due to the
CPU throttle reaching DEFAULT_MIGRATE_MAX_CPU_THROTTLE.

Signed-off-by: Lei Rao <lei.rao@intel.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Lukas Straub <lukasstraub2@web.de>
Tested-by: Lukas Straub <lukasstraub2@web.de>
---
 migration/colo.c | 4 ++++
 migration/ram.c  | 9 +++++++++
 migration/ram.h  | 1 +
 3 files changed, 14 insertions(+)

diff --git a/migration/colo.c b/migration/colo.c
index e3b1f13..2415325 100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -459,6 +459,10 @@ static int colo_do_checkpoint_transaction(MigrationState 
*s,
     if (ret < 0) {
         goto out;
     }
+
+    if (migrate_auto_converge()) {
+        mig_throttle_counter_reset();
+    }
     /*
      * Only save VM's live state, which not including device state.
      * TODO: We may need a timeout mechanism to prevent COLO process
diff --git a/migration/ram.c b/migration/ram.c
index 847af46..d5f98e6 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -641,6 +641,15 @@ static void mig_throttle_guest_down(uint64_t 
bytes_dirty_period,
     }
 }
 
+void mig_throttle_counter_reset(void)
+{
+    RAMState *rs = ram_state;
+
+    rs->time_last_bitmap_sync = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
+    rs->num_dirty_pages_period = 0;
+    rs->bytes_xfer_prev = ram_counters.transferred;
+}
+
 /**
  * xbzrle_cache_zero_page: insert a zero page in the XBZRLE cache
  *
diff --git a/migration/ram.h b/migration/ram.h
index dda1988..c515396 100644
--- a/migration/ram.h
+++ b/migration/ram.h
@@ -50,6 +50,7 @@ bool ramblock_is_ignored(RAMBlock *block);
 int xbzrle_cache_resize(uint64_t new_size, Error **errp);
 uint64_t ram_bytes_remaining(void);
 uint64_t ram_bytes_total(void);
+void mig_throttle_counter_reset(void);
 
 uint64_t ram_pagesize_summary(void);
 int ram_save_queue_pages(const char *rbname, ram_addr_t start, ram_addr_t len);
-- 
1.8.3.1