| Message ID | 20191006000249.29926-4-richardw.yang@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | migration/postcopy: replace have_listen_thread check with PostcopyState check | expand |
* Wei Yang (richardw.yang@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.yang@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? Dave > -- > 2.17.1 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On Tue, Oct 08, 2019 at 08:15:51PM +0100, Dr. David Alan Gilbert wrote: >* Wei Yang (richardw.yang@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.yang@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. >Dave > >> -- >> 2.17.1 >> >-- >Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
* Wei Yang (richardw.yang@linux.intel.com) wrote: > On Tue, Oct 08, 2019 at 08:15:51PM +0100, Dr. David Alan Gilbert wrote: > >* Wei Yang (richardw.yang@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.yang@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 / dgilbert@redhat.com / Manchester, UK > > -- > Wei Yang > Help you, Help me -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
On Wed, Oct 09, 2019 at 11:17:16AM +0100, Dr. David Alan Gilbert wrote: >* Wei Yang (richardw.yang@linux.intel.com) wrote: >> On Tue, Oct 08, 2019 at 08:15:51PM +0100, Dr. David Alan Gilbert wrote: >> >* Wei Yang (richardw.yang@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.yang@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 / dgilbert@redhat.com / Manchester, UK >> >> -- >> Wei Yang >> Help you, Help me >-- >Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
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); 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; }
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.yang@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(-)