From 12808db3b8c22d26c9bc3da6f41756890ce882e4 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Fri, 2 Feb 2024 18:28:53 +0800 Subject: [PATCH] migration/multifd: Cleanup multifd_save_cleanup() Shrink the function by moving relevant works into helpers: move the thread join()s into multifd_send_terminate_threads(), then create two more helpers to cover channel/state cleanups. Add a TODO entry for the thread terminate process because p->running is still buggy. We need to fix it at some point but not yet covered. Suggested-by: Fabiano Rosas Reviewed-by: Fabiano Rosas Link: https://lore.kernel.org/r/20240202102857.110210-20-peterx@redhat.com Signed-off-by: Peter Xu --- migration/multifd.c | 91 +++++++++++++++++++++++++++++---------------- 1 file changed, 59 insertions(+), 32 deletions(-) diff --git a/migration/multifd.c b/migration/multifd.c index 4ab8e6eff2..4cb0d2cc17 100644 --- a/migration/multifd.c +++ b/migration/multifd.c @@ -593,6 +593,11 @@ static void multifd_send_terminate_threads(void) * always set it. */ qatomic_set(&multifd_send_state->exiting, 1); + + /* + * Firstly, kick all threads out; no matter whether they are just idle, + * or blocked in an IO system call. + */ for (i = 0; i < migrate_multifd_channels(); i++) { MultiFDSendParams *p = &multifd_send_state->params[i]; @@ -601,6 +606,21 @@ static void multifd_send_terminate_threads(void) qio_channel_shutdown(p->c, QIO_CHANNEL_SHUTDOWN_BOTH, NULL); } } + + /* + * Finally recycle all the threads. + * + * TODO: p->running is still buggy, e.g. we can reach here without the + * corresponding multifd_new_send_channel_async() get invoked yet, + * then a new thread can even be created after this function returns. + */ + for (i = 0; i < migrate_multifd_channels(); i++) { + MultiFDSendParams *p = &multifd_send_state->params[i]; + + if (p->running) { + qemu_thread_join(&p->thread); + } + } } static int multifd_send_channel_destroy(QIOChannel *send) @@ -608,6 +628,41 @@ static int multifd_send_channel_destroy(QIOChannel *send) return socket_send_channel_destroy(send); } +static bool multifd_send_cleanup_channel(MultiFDSendParams *p, Error **errp) +{ + if (p->registered_yank) { + migration_ioc_unregister_yank(p->c); + } + multifd_send_channel_destroy(p->c); + p->c = NULL; + qemu_mutex_destroy(&p->mutex); + qemu_sem_destroy(&p->sem); + qemu_sem_destroy(&p->sem_sync); + g_free(p->name); + p->name = NULL; + multifd_pages_clear(p->pages); + p->pages = NULL; + p->packet_len = 0; + g_free(p->packet); + p->packet = NULL; + g_free(p->iov); + p->iov = NULL; + multifd_send_state->ops->send_cleanup(p, errp); + + return *errp == NULL; +} + +static void multifd_send_cleanup_state(void) +{ + qemu_sem_destroy(&multifd_send_state->channels_ready); + g_free(multifd_send_state->params); + multifd_send_state->params = NULL; + multifd_pages_clear(multifd_send_state->pages); + multifd_send_state->pages = NULL; + g_free(multifd_send_state); + multifd_send_state = NULL; +} + void multifd_save_cleanup(void) { int i; @@ -615,48 +670,20 @@ void multifd_save_cleanup(void) if (!migrate_multifd()) { return; } + multifd_send_terminate_threads(); - for (i = 0; i < migrate_multifd_channels(); i++) { - MultiFDSendParams *p = &multifd_send_state->params[i]; - if (p->running) { - qemu_thread_join(&p->thread); - } - } for (i = 0; i < migrate_multifd_channels(); i++) { MultiFDSendParams *p = &multifd_send_state->params[i]; Error *local_err = NULL; - if (p->registered_yank) { - migration_ioc_unregister_yank(p->c); - } - multifd_send_channel_destroy(p->c); - p->c = NULL; - qemu_mutex_destroy(&p->mutex); - qemu_sem_destroy(&p->sem); - qemu_sem_destroy(&p->sem_sync); - g_free(p->name); - p->name = NULL; - multifd_pages_clear(p->pages); - p->pages = NULL; - p->packet_len = 0; - g_free(p->packet); - p->packet = NULL; - g_free(p->iov); - p->iov = NULL; - multifd_send_state->ops->send_cleanup(p, &local_err); - if (local_err) { + if (!multifd_send_cleanup_channel(p, &local_err)) { migrate_set_error(migrate_get_current(), local_err); error_free(local_err); } } - qemu_sem_destroy(&multifd_send_state->channels_ready); - g_free(multifd_send_state->params); - multifd_send_state->params = NULL; - multifd_pages_clear(multifd_send_state->pages); - multifd_send_state->pages = NULL; - g_free(multifd_send_state); - multifd_send_state = NULL; + + multifd_send_cleanup_state(); } static int multifd_zero_copy_flush(QIOChannel *c) -- 2.39.5