* Wei Yang (richardw.y...@linux.intel.com) wrote: > On Tue, Oct 08, 2019 at 08:15:51PM +0100, Dr. David Alan Gilbert wrote: > >* Wei Yang (richardw.y...@linux.intel.com) wrote: > >> After previous cleanup, postcopy thread is running only when > >> PostcopyState is LISTENNING or RUNNING. This means it is not necessary > >> to spare a variable have_listen_thread to represent the state. > >> > >> Replace the check on have_listen_thread with PostcopyState and remove > >> the variable. > >> > >> Signed-off-by: Wei Yang <richardw.y...@linux.intel.com> > >> --- > >> migration/migration.h | 1 - > >> migration/ram.c | 2 +- > >> migration/ram.h | 1 + > >> migration/savevm.c | 4 +--- > >> 4 files changed, 3 insertions(+), 5 deletions(-) > >> > >> diff --git a/migration/migration.h b/migration/migration.h > >> index 4f2fe193dc..a4d639663d 100644 > >> --- a/migration/migration.h > >> +++ b/migration/migration.h > >> @@ -63,7 +63,6 @@ struct MigrationIncomingState { > >> /* Set this when we want the fault thread to quit */ > >> bool fault_thread_quit; > >> > >> - bool have_listen_thread; > >> QemuThread listen_thread; > >> QemuSemaphore listen_thread_sem; > >> > >> diff --git a/migration/ram.c b/migration/ram.c > >> index 769d3f6454..dfc50d57d5 100644 > >> --- a/migration/ram.c > >> +++ b/migration/ram.c > >> @@ -4188,7 +4188,7 @@ static bool postcopy_is_advised(void) > >> return ps >= POSTCOPY_INCOMING_ADVISE && ps < POSTCOPY_INCOMING_END; > >> } > >> > >> -static bool postcopy_is_running(void) > >> +bool postcopy_is_running(void) > >> { > >> PostcopyState ps = postcopy_state_get(); > >> return ps >= POSTCOPY_INCOMING_LISTENING && ps < > >> POSTCOPY_INCOMING_END; > >> diff --git a/migration/ram.h b/migration/ram.h > >> index bd0eee79b6..44fe4753ad 100644 > >> --- a/migration/ram.h > >> +++ b/migration/ram.h > >> @@ -59,6 +59,7 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms); > >> /* For incoming postcopy discard */ > >> int ram_discard_range(const char *block_name, uint64_t start, size_t > >> length); > >> int ram_postcopy_incoming_init(MigrationIncomingState *mis); > >> +bool postcopy_is_running(void); > >> > >> void ram_handle_compressed(void *host, uint8_t ch, uint64_t size); > >> > >> diff --git a/migration/savevm.c b/migration/savevm.c > >> index dcad8897a3..2a0e0b94df 100644 > >> --- a/migration/savevm.c > >> +++ b/migration/savevm.c > >> @@ -1836,7 +1836,6 @@ static void *postcopy_ram_listen_thread(void *opaque) > >> qemu_loadvm_state_cleanup(); > >> > >> rcu_unregister_thread(); > >> - mis->have_listen_thread = false; > >> postcopy_state_set(POSTCOPY_INCOMING_END, NULL); > > > >That now needs a big comment saying it must be the last thing in the > >thread, because now it's got meaning that it's here. > > > >> > >> return NULL; > >> @@ -1880,7 +1879,6 @@ static int > >> loadvm_postcopy_handle_listen(MigrationIncomingState *mis) > >> return -1; > >> } > >> > >> - mis->have_listen_thread = true; > >> /* Start up the listening thread and wait for it to signal ready */ > >> qemu_sem_init(&mis->listen_thread_sem, 0); > >> qemu_thread_create(&mis->listen_thread, "postcopy/listen", > >> @@ -2518,7 +2516,7 @@ int qemu_loadvm_state(QEMUFile *f) > >> > >> trace_qemu_loadvm_state_post_main(ret); > >> > >> - if (mis->have_listen_thread) { > >> + if (postcopy_is_running()) { > >> /* Listen thread still going, can't clean up yet */ > >> return ret; > >> } > > > >Can you explain to me why this is afe in the case of a failure in > >loadvm_postcopy_handle_listen between the start where it sets > >the state to LISTENING, and the point where it currently sets > >hasve_listen_thread ? Wouldn't this cause qemu_loadvm_state > >not to cleanup? > > > > I have to say you are right. listen_thread may not started when PostcopyState > is already set to LISTENING. > > The ugly fix may be set PostcopyState back to original one. Not sure whether > you would like this.
I think the 'have_listen_thread' might be the simplest solution though; it's very simple! Dave > >Dave > > > >> -- > >> 2.17.1 > >> > >-- > >Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK > > -- > Wei Yang > Help you, Help me -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK