migration/multifd: Stop checking p->quit in multifd_send_thread

We don't need to check p->quit in the multifd_send_thread() because it
is shadowed by the 'exiting' flag. Ever since that flag was added
p->quit became obsolete as a way to stop the thread.

Since p->quit is set at multifd_send_terminate_threads() under the
p->mutex lock, the thread will only see it once it loops, so 'exiting'
will always be seen first.

Note that setting p->quit at multifd_send_terminate_threads() still
makes sense because we need a way to inform multifd_send_pages() that
the channel has stopped.

Signed-off-by: Fabiano Rosas <farosas@suse.de>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <20231012140651.13122-3-farosas@suse.de>

diff --git a/migration/multifd.c b/migration/multifd.c
index 1fe53d3b980eb85160332f6db2ad6734ecc58849..e2a45c667aa780c123f697ea95d6fa0b86560f3a 100644 (file)
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -743,9 +743,6 @@ static void *multifd_send_thread(void *opaque)
             if (flags & MULTIFD_FLAG_SYNC) {
                 qemu_sem_post(&p->sem_sync);
             }
-        } else if (p->quit) {
-            qemu_mutex_unlock(&p->mutex);
-            break;
         } else {
             qemu_mutex_unlock(&p->mutex);
             /* sometimes there are spurious wakeups */