diff --git a/migration/ram.c b/migration/ram.c index b9147bcca3..f946282adb 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -900,6 +900,12 @@ struct { uint64_t packet_num; /* send channels ready */ QemuSemaphore channels_ready; + /* + * Have we already run terminate threads. There is a race when it + * happens that we got one error while we are exiting. + * We will use atomic operations. Only valid values are 0 and 1. + */ + int exiting; } *multifd_send_state; /* @@ -928,6 +934,10 @@ static int multifd_send_pages(RAMState *rs) MultiFDPages_t *pages = multifd_send_state->pages; uint64_t transferred; + if (atomic_read(&multifd_send_state->exiting)) { + return -1; + } + qemu_sem_wait(&multifd_send_state->channels_ready); for (i = next_channel;; i = (i + 1) % migrate_multifd_channels()) { p = &multifd_send_state->params[i]; @@ -1009,6 +1019,16 @@ static void multifd_send_terminate_threads(Error *err) } } + /* + * We don't want to exit each threads twice. Depending on where + * we get the error, or if there are two independent errors in two + * threads at the same time, we can end calling this function + * twice. + */ + if (atomic_xchg(&multifd_send_state->exiting, 1)) { + return; + } + for (i = 0; i < migrate_multifd_channels(); i++) { MultiFDSendParams *p = &multifd_send_state->params[i]; @@ -1118,6 +1138,10 @@ static void *multifd_send_thread(void *opaque) while (true) { qemu_sem_wait(&p->sem); + + if (atomic_read(&multifd_send_state->exiting)) { + break; + } qemu_mutex_lock(&p->mutex); if (p->pending_job) { @@ -1224,6 +1248,7 @@ int multifd_save_setup(void) multifd_send_state->params = g_new0(MultiFDSendParams, thread_count); multifd_send_state->pages = multifd_pages_init(page_count); qemu_sem_init(&multifd_send_state->channels_ready, 0); + atomic_set(&multifd_send_state->exiting, 0); for (i = 0; i < thread_count; i++) { MultiFDSendParams *p = &multifd_send_state->params[i];