* Juan Quintela (quint...@redhat.com) wrote:
> If we are exiting due to an error/finish/.... Just don't try to even
> touch the channel with one IO operation.
>
> Signed-off-by: Juan Quintela <quint...@redhat.com>
> Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> Signed-off-by: Juan Quintela <quint...@redhat.com>
> ---
> migration/ram.c | 25 +++++++++++++++++++++++++
> 1 file changed, 25 insertions(+)
>
> diff --git a/migration/ram.c b/migration/ram.c
> index 96feb4062c..6e678dbd2e 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.
> + */
Yeh that makes it cleaer. Thanks
> + 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];
> --
> 2.24.1
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
