static void *buffered_file_thread(void *opaque) { MigrationState *s = opaque; int64_t initial_time = qemu_get_clock_ms(rt_clock); int64_t sleep_time = 0; int64_t max_size = 0; bool last_round = false; int ret; qemu_mutex_lock_iothread(); DPRINTF("beginning savevm\n"); ret = qemu_savevm_state_begin(s->file, &s->params); qemu_mutex_unlock_iothread(); while (ret >= 0) { int64_t current_time; uint64_t pending_size; qemu_mutex_lock_iothread(); if (s->state != MIG_STATE_ACTIVE) { DPRINTF("put_ready returning because of non-active state\n"); qemu_mutex_unlock_iothread(); break; } if (s->complete) { qemu_mutex_unlock_iothread(); break; } if (s->bytes_xfer < s->xfer_limit) { DPRINTF("iterate\n"); pending_size = qemu_savevm_state_pending(s->file, max_size); DPRINTF("pending size %lu max %lu\n", pending_size, max_size); if (pending_size && pending_size >= max_size) { ret = qemu_savevm_state_iterate(s->file); if (ret < 0) { qemu_mutex_unlock_iothread(); break; } } else { int old_vm_running = runstate_is_running(); int64_t start_time, end_time; DPRINTF("done iterating\n"); start_time = qemu_get_clock_ms(rt_clock); qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER); vm_stop_force_state(RUN_STATE_FINISH_MIGRATE); ret = qemu_savevm_state_complete(s->file); if (ret < 0) { qemu_mutex_unlock_iothread(); break; } else { migrate_fd_completed(s); } end_time = qemu_get_clock_ms(rt_clock); s->total_time = end_time - s->total_time; s->downtime = end_time - start_time; if (s->state != MIG_STATE_COMPLETED) { if (old_vm_running) { vm_start(); } } last_round = true; } } qemu_mutex_unlock_iothread(); current_time = qemu_get_clock_ms(rt_clock); if (current_time >= initial_time + BUFFER_DELAY) { uint64_t transferred_bytes = s->bytes_xfer; uint64_t time_spent = current_time - initial_time - sleep_time; double bandwidth = transferred_bytes / time_spent; max_size = bandwidth * migrate_max_downtime() / 1000000; DPRINTF("transferred %" PRIu64 " time_spent %" PRIu64 " bandwidth %g max_size %" PRId64 "\n", transferred_bytes, time_spent, bandwidth, max_size); /* if we haven't sent anything, we don't want to recalculate 10000 is a small enough number for our purposes */ if (s->dirty_bytes_rate && transferred_bytes > 10000) { s->expected_downtime = s->dirty_bytes_rate / bandwidth; } s->bytes_xfer = 0; sleep_time = 0; initial_time = current_time; } if (!last_round && (s->bytes_xfer >= s->xfer_limit)) { /* usleep expects microseconds */ g_usleep((initial_time + BUFFER_DELAY - current_time)*1000); sleep_time += qemu_get_clock_ms(rt_clock) - current_time; } buffered_flush(s); ret = qemu_file_get_error(s->file); } if (ret < 0) { migrate_fd_error(s); } g_free(s->buffer); return NULL; }