* Lidong Chen (jemmy858...@gmail.com) wrote: > ibv_dereg_mr wait for a long time for big memory size virtual server. > > The test result is: > 10GB 326ms > 20GB 699ms > 30GB 1021ms > 40GB 1387ms > 50GB 1712ms > 60GB 2034ms > 70GB 2457ms > 80GB 2807ms > 90GB 3107ms > 100GB 3474ms > 110GB 3735ms > 120GB 4064ms > 130GB 4567ms > 140GB 4886ms > > this will cause the guest os hang for a while when migration finished. > So create a dedicated thread to release rdma resource. > > Signed-off-by: Lidong Chen <lidongc...@tencent.com> > --- > migration/migration.c | 6 ++++++ > migration/migration.h | 3 +++ > migration/rdma.c | 47 +++++++++++++++++++++++++++++++---------------- > 3 files changed, 40 insertions(+), 16 deletions(-) > > diff --git a/migration/migration.c b/migration/migration.c > index f7d6e26..25d9009 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -1499,6 +1499,7 @@ void migrate_init(MigrationState *s) > s->vm_was_running = false; > s->iteration_initial_bytes = 0; > s->threshold_size = 0; > + s->rdma_cleanup_thread_quit = true; > } > > static GSList *migration_blockers; > @@ -1660,6 +1661,10 @@ static bool migrate_prepare(MigrationState *s, bool > blk, bool blk_inc, > return false; > } > > + if (s->rdma_cleanup_thread_quit != true) { > + return false; > + }
That's not good! We error out without saying anything to the user about why; if we error we must always say why, otherwise we'll get bug reports from people without anyway to debug them. However, we also don't need to; all we need to do is turn this into a semaphore or similar, and then wait for it at the start of 'rdma_start_outgoing_migration' - that way there's no error exit, it just waits a few seconds and then carries on correctly. (Maybe we need to wait in incoming as well to cope with postcopy-recovery). Dave > if (runstate_check(RUN_STATE_INMIGRATE)) { > error_setg(errp, "Guest is waiting for an incoming migration"); > return false; > @@ -3213,6 +3218,7 @@ static void migration_instance_init(Object *obj) > > ms->state = MIGRATION_STATUS_NONE; > ms->mbps = -1; > + ms->rdma_cleanup_thread_quit = true; > qemu_sem_init(&ms->pause_sem, 0); > qemu_mutex_init(&ms->error_mutex); > > diff --git a/migration/migration.h b/migration/migration.h > index 64a7b33..60138dd 100644 > --- a/migration/migration.h > +++ b/migration/migration.h > @@ -224,6 +224,9 @@ struct MigrationState > * do not trigger spurious decompression errors. > */ > bool decompress_error_check; > + > + /* Set this when rdma resource have released */ > + bool rdma_cleanup_thread_quit; > }; > > void migrate_set_state(int *state, int old_state, int new_state); > diff --git a/migration/rdma.c b/migration/rdma.c > index e1498f2..3282f35 100644 > --- a/migration/rdma.c > +++ b/migration/rdma.c > @@ -2995,35 +2995,50 @@ static void > qio_channel_rdma_set_aio_fd_handler(QIOChannel *ioc, > } > } > > -static int qio_channel_rdma_close(QIOChannel *ioc, > - Error **errp) > +static void *qio_channel_rdma_close_thread(void *arg) > { > - QIOChannelRDMA *rioc = QIO_CHANNEL_RDMA(ioc); > - RDMAContext *rdmain, *rdmaout; > - trace_qemu_rdma_close(); > - > - rdmain = rioc->rdmain; > - if (rdmain) { > - atomic_rcu_set(&rioc->rdmain, NULL); > - } > + RDMAContext **rdma = arg; > + RDMAContext *rdmain = rdma[0]; > + RDMAContext *rdmaout = rdma[1]; > + MigrationState *s = migrate_get_current(); > > - rdmaout = rioc->rdmaout; > - if (rdmaout) { > - atomic_rcu_set(&rioc->rdmaout, NULL); > - } > + rcu_register_thread(); > > synchronize_rcu(); > - > if (rdmain) { > qemu_rdma_cleanup(rdmain); > } > - > if (rdmaout) { > qemu_rdma_cleanup(rdmaout); > } > > g_free(rdmain); > g_free(rdmaout); > + g_free(rdma); > + > + rcu_unregister_thread(); > + s->rdma_cleanup_thread_quit = true; > + return NULL; > +} > + > +static int qio_channel_rdma_close(QIOChannel *ioc, > + Error **errp) > +{ > + QemuThread t; > + QIOChannelRDMA *rioc = QIO_CHANNEL_RDMA(ioc); > + RDMAContext **rdma = g_new0(RDMAContext*, 2); > + MigrationState *s = migrate_get_current(); > + > + trace_qemu_rdma_close(); > + if (rioc->rdmain || rioc->rdmaout) { > + rdma[0] = rioc->rdmain; > + rdma[1] = rioc->rdmaout; > + atomic_rcu_set(&rioc->rdmain, NULL); > + atomic_rcu_set(&rioc->rdmaout, NULL); > + s->rdma_cleanup_thread_quit = false; > + qemu_thread_create(&t, "rdma cleanup", qio_channel_rdma_close_thread, > + rdma, QEMU_THREAD_DETACHED); > + } > > return 0; > } > -- > 1.8.3.1 > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK