From: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
Implement dirty-limit convergence algo for live migration,
which is kind of like auto-converge algo but using dirty-limit
instead of cpu throttle to make migration convergent.
Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
---
migration/migration.c | 1 +
migration/ram.c | 53 +++++++++++++++++++++++++++++++++++++-------------
migration/trace-events | 1 +
3 files changed, 42 insertions(+), 13 deletions(-)
diff --git a/migration/migration.c b/migration/migration.c
index d117bb4..64696de 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -239,6 +239,7 @@ void migration_cancel(const Error *error)
if (error) {
migrate_set_error(current_migration, error);
}
+ qmp_cancel_vcpu_dirty_limit(false, -1, NULL);
migrate_fd_cancel(current_migration);
}
diff --git a/migration/ram.c b/migration/ram.c
index dc1de9d..cc19c5e 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -45,6 +45,7 @@
#include "qapi/error.h"
#include "qapi/qapi-types-migration.h"
#include "qapi/qapi-events-migration.h"
+#include "qapi/qapi-commands-migration.h"
#include "qapi/qmp/qerror.h"
#include "trace.h"
#include "exec/ram_addr.h"
@@ -57,6 +58,8 @@
#include "qemu/iov.h"
#include "multifd.h"
#include "sysemu/runstate.h"
+#include "sysemu/dirtylimit.h"
+#include "sysemu/kvm.h"
#include "hw/boards.h" /* for machine_dump_guest_core() */
@@ -1139,6 +1142,21 @@ static void migration_update_rates(RAMState *rs, int64_t end_time)
}
}
+/*
+ * Enable dirty-limit to throttle down the guest
+ */
+static void migration_dirty_limit_guest(void)
+{
+ if (!dirtylimit_in_service()) {
+ MigrationState *s = migrate_get_current();
+ int64_t quota_dirtyrate = s->parameters.x_vcpu_dirty_limit;
+
+ /* Set quota dirtyrate if dirty limit not in service */
+ qmp_set_vcpu_dirty_limit(false, -1, quota_dirtyrate, NULL);
+ trace_migration_dirty_limit_guest(quota_dirtyrate);
+ }
+}
+
static void migration_trigger_throttle(RAMState *rs)
{
MigrationState *s = migrate_get_current();
@@ -1148,22 +1166,31 @@ static void migration_trigger_throttle(RAMState *rs)
uint64_t bytes_dirty_period = rs->num_dirty_pages_period *
TARGET_PAGE_SIZE;
uint64_t bytes_dirty_threshold = bytes_xfer_period * threshold / 100;
- /* 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 ratio between dirtied bytes and the approx.
- amount of bytes that just got transferred since the last time
- we were in this routine reaches the threshold. If that happens
- twice, start or increase throttling. */
-
- if ((bytes_dirty_period > bytes_dirty_threshold) &&
- (++rs->dirty_rate_high_cnt >= 2)) {
+ /*
+ * The following detection logic can be refined later. For now:
+ * Check to see if the ratio between dirtied bytes and the approx.
+ * amount of bytes that just got transferred since the last time
+ * we were in this routine reaches the threshold. If that happens
+ * twice, start or increase throttling.
+ */
+
+ if ((bytes_dirty_period > bytes_dirty_threshold) &&
+ (++rs->dirty_rate_high_cnt >= 2)) {
+ rs->dirty_rate_high_cnt = 0;
+ /*
+ * 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()) {
trace_migration_throttle();
- rs->dirty_rate_high_cnt = 0;
mig_throttle_guest_down(bytes_dirty_period,
bytes_dirty_threshold);
+ } else if (migrate_dirty_limit() &&
+ kvm_dirty_ring_enabled() &&
+ migration_is_active(s)) {
+ migration_dirty_limit_guest();