On Wed, Oct 09, 2019 at 11:17:16AM +0100, Dr. David Alan Gilbert wrote: >* 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! >
Yep, you are right. >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 -- Wei Yang Help you, Help me