Commit f193bc0c authored by Ivan Ren's avatar Ivan Ren Committed by Juan Quintela
Browse files

migration: fix migrate_cancel multifd migration leads destination hung forever 



When migrate_cancel a multifd migration, if run sequence like this:

        [source]                              [destination]

multifd_send_sync_main[finish]
                                    multifd_recv_thread wait &p->sem_sync
shutdown to_dst_file
                                    detect error from_src_file
send  RAM_SAVE_FLAG_EOS[fail]       [no chance to run multifd_recv_sync_main]
                                    multifd_load_cleanup
                                    join multifd receive thread forever

will lead destination qemu hung at following stack:

pthread_join
qemu_thread_join
multifd_load_cleanup
process_incoming_migration_co
coroutine_trampoline

Signed-off-by: default avatarIvan Ren <ivanren@tencent.com>
Reviewed-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: default avatarJuan Quintela <quintela@redhat.com>
Message-Id: <1561468699-9819-4-git-send-email-ivanren@tencent.com>
Signed-off-by: default avatarJuan Quintela <quintela@redhat.com>
parent 3c3ca25d

migration/ram.c

+5 −0
Original line number Diff line number Diff line
@@ -1292,6 +1292,11 @@ int multifd_load_cleanup(Error **errp) 


        if (p->running) {

            p->quit = true;

            /*

             * multifd_recv_thread may hung at MULTIFD_FLAG_SYNC handle code,

             * however try to wakeup it without harm in cleanup phase.

             */

            qemu_sem_post(&p->sem_sync);

            qemu_thread_join(&p->thread);

        }

        object_unref(OBJECT(p->c));