* Juan Quintela (quintela@xxxxxxxxxx) wrote:
> From: Ivan Ren <renyime@xxxxxxxxx>
>
> When we 'migrate_cancel' a multifd migration, live_migration thread may
> hung forever at some points, because of multifd_send_thread has already
> exit for socket error:
> 1. multifd_send_pages may hung at qemu_sem_wait(&multifd_send_state->
> channels_ready)
> 2. multifd_send_sync_main my hung at qemu_sem_wait(&multifd_send_state->
> sem_sync)
>
> Signed-off-by: Ivan Ren <ivanren@xxxxxxxxxxx>
> Message-Id: <1561468699-9819-3-git-send-email-ivanren@xxxxxxxxxxx>
> Reviewed-by: Juan Quintela <quintela@xxxxxxxxxx>
> Signed-off-by: Juan Quintela <quintela@xxxxxxxxxx>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@xxxxxxxxxx>
>
> ---
>
> Remove spurious not needed bits
> ---
> migration/ram.c | 16 ++++++++++++++--
> 1 file changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/migration/ram.c b/migration/ram.c
> index 52a2d498e4..87bb7da8e2 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -1097,7 +1097,8 @@ static void *multifd_send_thread(void *opaque)
> {
> MultiFDSendParams *p = opaque;
> Error *local_err = NULL;
> - int ret;
> + int ret = 0;
> + uint32_t flags = 0;
>
> trace_multifd_send_thread_start(p->id);
> rcu_register_thread();
> @@ -1115,7 +1116,7 @@ static void *multifd_send_thread(void *opaque)
> if (p->pending_job) {
> uint32_t used = p->pages->used;
> uint64_t packet_num = p->packet_num;
> - uint32_t flags = p->flags;
> + flags = p->flags;
>
> p->next_packet_size = used * qemu_target_page_size();
> multifd_send_fill_packet(p);
> @@ -1164,6 +1165,17 @@ out:
> multifd_send_terminate_threads(local_err);
> }
>
> + /*
> + * Error happen, I will exit, but I can't just leave, tell
> + * who pay attention to me.
> + */
> + if (ret != 0) {
> + if (flags & MULTIFD_FLAG_SYNC) {
> + qemu_sem_post(&multifd_send_state->sem_sync);
> + }
> + qemu_sem_post(&multifd_send_state->channels_ready);
> + }
> +
> qemu_mutex_lock(&p->mutex);
> p->running = false;
> qemu_mutex_unlock(&p->mutex);
> --
> 2.21.0
>
--
Dr. David Alan Gilbert / dgilbert@xxxxxxxxxx / Manchester, UK
