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[Qemu-devel] [PATCH 10/11] migration: major cleanup for migrate iteratio
From: |
Peter Xu |
Subject: |
[Qemu-devel] [PATCH 10/11] migration: major cleanup for migrate iterations |
Date: |
Wed, 3 Jan 2018 13:40:42 +0800 |
The major work for migration iterations are to move RAM/block/... data
via qemu_savevm_state_iterate(). Generalize those part into a single
function.
Signed-off-by: Peter Xu <address@hidden>
---
migration/migration.c | 90 +++++++++++++++++++++++++++++++--------------------
1 file changed, 55 insertions(+), 35 deletions(-)
diff --git a/migration/migration.c b/migration/migration.c
index 2629f907e9..c6c39738d2 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -2056,11 +2056,11 @@ static int migration_maybe_pause(MigrationState *s,
* The caller 'breaks' the loop when this returns.
*
* @s: Current migration state
- * @current_active_state: The migration state we expect to be in
*/
-static void migration_completion(MigrationState *s, int current_active_state)
+static void migration_completion(MigrationState *s)
{
int ret;
+ int current_active_state = s->state;
if (s->state == MIGRATION_STATUS_ACTIVE) {
qemu_mutex_lock_iothread();
@@ -2199,6 +2199,51 @@ static void migration_update_statistics(MigrationState
*s,
bandwidth, threshold_size);
}
+/* Migration thread iteration status */
+typedef enum {
+ MIG_ITERATE_RESUME, /* Resume current iteration */
+ MIG_ITERATE_SKIP, /* Skip current iteration */
+ MIG_ITERATE_BREAK, /* Break the loop */
+} MigIterateState;
+
+/*
+ * Return true if continue to the next iteration directly, false
+ * otherwise.
+ */
+static MigIterateState migration_iteration_run(MigrationState *s)
+{
+ uint64_t pending_size, pend_post, pend_nonpost;
+ bool in_postcopy = s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE;
+
+ qemu_savevm_state_pending(s->to_dst_file, s->threshold_size,
+ &pend_nonpost, &pend_post);
+ pending_size = pend_nonpost + pend_post;
+
+ trace_migrate_pending(pending_size, s->threshold_size,
+ pend_post, pend_nonpost);
+
+ if (pending_size && pending_size >= s->threshold_size) {
+ /* Still a significant amount to transfer */
+ if (migrate_postcopy() && !in_postcopy &&
+ pend_nonpost <= s->threshold_size &&
+ atomic_read(&s->start_postcopy)) {
+ if (postcopy_start(s)) {
+ error_report("%s: postcopy failed to start", __func__);
+ }
+ return MIG_ITERATE_SKIP;
+ }
+ /* Just another iteration step */
+ qemu_savevm_state_iterate(s->to_dst_file,
+ s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE);
+ } else {
+ trace_migration_thread_low_pending(pending_size);
+ migration_completion(s);
+ return MIG_ITERATE_BREAK;
+ }
+
+ return MIG_ITERATE_RESUME;
+}
+
/*
* Master migration thread on the source VM.
* It drives the migration and pumps the data down the outgoing channel.
@@ -2207,9 +2252,6 @@ static void *migration_thread(void *opaque)
{
MigrationState *s = opaque;
int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST);
- bool entered_postcopy = false;
- /* The active state we expect to be in; ACTIVE or POSTCOPY_ACTIVE */
- enum MigrationStatus current_active_state = MIGRATION_STATUS_ACTIVE;
rcu_register_thread();
@@ -2249,43 +2291,21 @@ static void *migration_thread(void *opaque)
while (s->state == MIGRATION_STATUS_ACTIVE ||
s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) {
int64_t current_time;
- uint64_t pending_size;
if (!qemu_file_rate_limit(s->to_dst_file)) {
- uint64_t pend_post, pend_nonpost;
-
- qemu_savevm_state_pending(s->to_dst_file, s->threshold_size,
- &pend_nonpost, &pend_post);
- pending_size = pend_nonpost + pend_post;
- trace_migrate_pending(pending_size, s->threshold_size,
- pend_post, pend_nonpost);
- if (pending_size && pending_size >= s->threshold_size) {
- /* Still a significant amount to transfer */
-
- if (migrate_postcopy() &&
- s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE &&
- pend_nonpost <= s->threshold_size &&
- atomic_read(&s->start_postcopy)) {
-
- if (!postcopy_start(s)) {
- current_active_state =
MIGRATION_STATUS_POSTCOPY_ACTIVE;
- entered_postcopy = true;
- }
-
- continue;
- }
- /* Just another iteration step */
- qemu_savevm_state_iterate(s->to_dst_file, entered_postcopy);
- } else {
- trace_migration_thread_low_pending(pending_size);
- migration_completion(s, current_active_state);
+ MigIterateState iter_state = migration_iteration_run(s);
+ if (iter_state == MIG_ITERATE_SKIP) {
+ continue;
+ } else if (iter_state == MIG_ITERATE_BREAK) {
break;
}
}
if (qemu_file_get_error(s->to_dst_file)) {
- migrate_set_state(&s->state, current_active_state,
- MIGRATION_STATUS_FAILED);
+ if (migration_is_setup_or_active(s->state)) {
+ migrate_set_state(&s->state, s->state,
+ MIGRATION_STATUS_FAILED);
+ }
trace_migration_thread_file_err();
break;
}
--
2.14.3