| Message ID | 20211110174156.3834330-1-chen.zhang@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] migration/colo: Optimize COLO start code path | expand |
Zhang Chen <chen.zhang@intel.com> wrote: > There is no need to start COLO through MIGRATION_STATUS_ACTIVE. Hi I don't understand what you are trying to do. In my reading, at least the commit message is wrong: void migrate_start_colo_process(MigrationState *s) { ... migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE, MIGRATION_STATUS_COLO); ... } and void *colo_process_incoming_thread(void *opaque) { ... migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, MIGRATION_STATUS_COLO); So colo starts with MIGRATION_STATUS_ACTIVE. > Signed-off-by: Zhang Chen <chen.zhang@intel.com> > --- > migration/colo.c | 2 -- > migration/migration.c | 18 +++++++++++------- > 2 files changed, 11 insertions(+), 9 deletions(-) > > diff --git a/migration/colo.c b/migration/colo.c > index 2415325262..ad1a4426b3 100644 > --- a/migration/colo.c > +++ b/migration/colo.c > @@ -667,8 +667,6 @@ void migrate_start_colo_process(MigrationState *s) > colo_checkpoint_notify, s); > > qemu_sem_init(&s->colo_exit_sem, 0); > - migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE, > - MIGRATION_STATUS_COLO); > colo_process_checkpoint(s); > qemu_mutex_lock_iothread(); > } > diff --git a/migration/migration.c b/migration/migration.c > index abaf6f9e3d..4c8662a839 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -3222,7 +3222,10 @@ static void migration_completion(MigrationState *s) > goto fail_invalidate; > } > > - if (!migrate_colo_enabled()) { > + if (migrate_colo_enabled()) { > + migrate_set_state(&s->state, current_active_state, > + MIGRATION_STATUS_COLO); > + } else { > migrate_set_state(&s->state, current_active_state, > MIGRATION_STATUS_COMPLETED); > } This moves the setup to MIGRATION_STATUS_COLO to completion time instead of the beggining of the process. I have no clue why. I guess you can put a comment/commit message to say what you ar.e trynig to do. > @@ -3607,12 +3610,7 @@ static void migration_iteration_finish(MigrationState *s) > migration_calculate_complete(s); > runstate_set(RUN_STATE_POSTMIGRATE); > break; > - > - case MIGRATION_STATUS_ACTIVE: > - /* > - * We should really assert here, but since it's during > - * migration, let's try to reduce the usage of assertions. > - */ > + case MIGRATION_STATUS_COLO: > if (!migrate_colo_enabled()) { > error_report("%s: critical error: calling COLO code without " > "COLO enabled", __func__); > @@ -3622,6 +3620,12 @@ static void migration_iteration_finish(MigrationState *s) > * Fixme: we will run VM in COLO no matter its old running state. > * After exited COLO, we will keep running. > */ > + /* Fallthrough */ > + case MIGRATION_STATUS_ACTIVE: > + /* > + * We should really assert here, but since it's during > + * migration, let's try to reduce the usage of assertions. > + */ > s->vm_was_running = true; > /* Fallthrough */ > case MIGRATION_STATUS_FAILED: I guess this change is related to the previous one, but I don't understand colo enough to review it. Later, Juan.
> -----Original Message----- > From: Juan Quintela <quintela@redhat.com> > Sent: Wednesday, November 17, 2021 12:28 AM > To: Zhang, Chen <chen.zhang@intel.com> > Cc: Hailiang Zhang <zhang.zhanghailiang@huawei.com>; Dr . David Alan > Gilbert <dgilbert@redhat.com>; qemu-dev <qemu-devel@nongnu.org> > Subject: Re: [PATCH 1/2] migration/colo: Optimize COLO start code path > > Zhang Chen <chen.zhang@intel.com> wrote: > > There is no need to start COLO through MIGRATION_STATUS_ACTIVE. > > Hi > > I don't understand what you are trying to do. In my reading, at least the > commit message is wrong: > > void migrate_start_colo_process(MigrationState *s) { > ... > migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE, > MIGRATION_STATUS_COLO); > ... > } > > and > > void *colo_process_incoming_thread(void *opaque) { > ... > migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, > MIGRATION_STATUS_COLO); > > So colo starts with MIGRATION_STATUS_ACTIVE. Yes, this patch just optimized COLO primary code path(migrate_start_colo_process()). We can see this patch removed the migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE, MIGRATION_STATUS_COLO); In the migrate_start_colo_process(). Current COLO status path: MIGRATION_STATUS_XXX ---> MIGRATION_STATUS_ACTIVE ---> MIGRATION_STATUS_COLO ---> MIGRATION_STATUS_COMPLETED This patch try to remove redundant " MIGRATION_STATUS_ACTIVE " in COLO start. MIGRATION_STATUS_XXX ---> MIGRATION_STATUS_COLO ---> MIGRATION_STATUS_COMPLETED Actually COLO primary code did nothing when running on "MIGRATION_STATUS_ACTIVE". But for COLO secondary (void *colo_process_incoming_thread()), it shared some code with normal migration. No need to do this. So, I will fix commit message to: Optimize COLO primary start path to: MIGRATION_STATUS_XXX ---> MIGRATION_STATUS_COLO ---> MIGRATION_STATUS_COMPLETED No need to start primary COLO through "MIGRATION_STATUS_ACTIVE". How about it? > > > > Signed-off-by: Zhang Chen <chen.zhang@intel.com> > > --- > > migration/colo.c | 2 -- > > migration/migration.c | 18 +++++++++++------- > > 2 files changed, 11 insertions(+), 9 deletions(-) > > > > diff --git a/migration/colo.c b/migration/colo.c index > > 2415325262..ad1a4426b3 100644 > > --- a/migration/colo.c > > +++ b/migration/colo.c > > @@ -667,8 +667,6 @@ void migrate_start_colo_process(MigrationState *s) > > colo_checkpoint_notify, s); > > > > qemu_sem_init(&s->colo_exit_sem, 0); > > - migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE, > > - MIGRATION_STATUS_COLO); > > colo_process_checkpoint(s); > > qemu_mutex_lock_iothread(); > > } > > diff --git a/migration/migration.c b/migration/migration.c index > > abaf6f9e3d..4c8662a839 100644 > > --- a/migration/migration.c > > +++ b/migration/migration.c > > @@ -3222,7 +3222,10 @@ static void migration_completion(MigrationState > *s) > > goto fail_invalidate; > > } > > > > - if (!migrate_colo_enabled()) { > > + if (migrate_colo_enabled()) { > > + migrate_set_state(&s->state, current_active_state, > > + MIGRATION_STATUS_COLO); > > + } else { > > migrate_set_state(&s->state, current_active_state, > > MIGRATION_STATUS_COMPLETED); > > } > > This moves the setup to MIGRATION_STATUS_COLO to completion time > instead of the beggining of the process. I have no clue why. I guess you can > put a comment/commit message to say what you ar.e trynig to do. You are right, no need to setup here. I will remove this in next version. > > > @@ -3607,12 +3610,7 @@ static void > migration_iteration_finish(MigrationState *s) > > migration_calculate_complete(s); > > runstate_set(RUN_STATE_POSTMIGRATE); > > break; > > - > > - case MIGRATION_STATUS_ACTIVE: > > - /* > > - * We should really assert here, but since it's during > > - * migration, let's try to reduce the usage of assertions. > > - */ > > + case MIGRATION_STATUS_COLO: > > if (!migrate_colo_enabled()) { > > error_report("%s: critical error: calling COLO code without " > > "COLO enabled", __func__); @@ -3622,6 > > +3620,12 @@ static void migration_iteration_finish(MigrationState *s) > > * Fixme: we will run VM in COLO no matter its old running state. > > * After exited COLO, we will keep running. > > */ > > + /* Fallthrough */ > > + case MIGRATION_STATUS_ACTIVE: > > + /* > > + * We should really assert here, but since it's during > > + * migration, let's try to reduce the usage of assertions. > > + */ > > s->vm_was_running = true; > > /* Fallthrough */ > > case MIGRATION_STATUS_FAILED: > > I guess this change is related to the previous one, but I don't understand colo > enough to review it. I think this patch is the general code, little background needed. You can simple understand COLO is two VMs(primary node and secondary node) entered a state of cyclic migration. Thanks your comments. Thanks Chen > > Later, Juan.
"Zhang, Chen" <chen.zhang@intel.com> wrote: >> -----Original Message----- >> From: Juan Quintela <quintela@redhat.com> >> Sent: Wednesday, November 17, 2021 12:28 AM >> To: Zhang, Chen <chen.zhang@intel.com> >> Cc: Hailiang Zhang <zhang.zhanghailiang@huawei.com>; Dr . David Alan >> Gilbert <dgilbert@redhat.com>; qemu-dev <qemu-devel@nongnu.org> >> Subject: Re: [PATCH 1/2] migration/colo: Optimize COLO start code path >> >> Zhang Chen <chen.zhang@intel.com> wrote: >> > There is no need to start COLO through MIGRATION_STATUS_ACTIVE. >> >> Hi >> >> I don't understand what you are trying to do. In my reading, at least the >> commit message is wrong: >> >> void migrate_start_colo_process(MigrationState *s) { >> ... >> migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE, >> MIGRATION_STATUS_COLO); >> ... >> } >> >> and >> >> void *colo_process_incoming_thread(void *opaque) { >> ... >> migrate_set_state(&mis->state, MIGRATION_STATUS_ACTIVE, >> MIGRATION_STATUS_COLO); >> >> So colo starts with MIGRATION_STATUS_ACTIVE. > > Yes, this patch just optimized COLO primary code path(migrate_start_colo_process()). > We can see this patch removed the > migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE, > MIGRATION_STATUS_COLO); > In the migrate_start_colo_process(). > > Current COLO status path: > MIGRATION_STATUS_XXX ---> MIGRATION_STATUS_ACTIVE ---> MIGRATION_STATUS_COLO ---> MIGRATION_STATUS_COMPLETED > > This patch try to remove redundant " MIGRATION_STATUS_ACTIVE " in COLO start. > MIGRATION_STATUS_XXX ---> MIGRATION_STATUS_COLO ---> MIGRATION_STATUS_COMPLETED > > Actually COLO primary code did nothing when running on "MIGRATION_STATUS_ACTIVE". > But for COLO secondary (void *colo_process_incoming_thread()), it shared some code with normal migration. No need to do this. > > So, I will fix commit message to: > Optimize COLO primary start path to: > MIGRATION_STATUS_XXX ---> MIGRATION_STATUS_COLO ---> MIGRATION_STATUS_COMPLETED > No need to start primary COLO through "MIGRATION_STATUS_ACTIVE". > > How about it? Much better, thank.s >> > Signed-off-by: Zhang Chen <chen.zhang@intel.com> >> > --- >> > migration/colo.c | 2 -- >> > migration/migration.c | 18 +++++++++++------- >> > 2 files changed, 11 insertions(+), 9 deletions(-) >> > >> > diff --git a/migration/colo.c b/migration/colo.c index >> > 2415325262..ad1a4426b3 100644 >> > --- a/migration/colo.c >> > +++ b/migration/colo.c >> > @@ -667,8 +667,6 @@ void migrate_start_colo_process(MigrationState *s) >> > colo_checkpoint_notify, s); >> > >> > qemu_sem_init(&s->colo_exit_sem, 0); >> > - migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE, >> > - MIGRATION_STATUS_COLO); >> > colo_process_checkpoint(s); >> > qemu_mutex_lock_iothread(); >> > } >> > diff --git a/migration/migration.c b/migration/migration.c index >> > abaf6f9e3d..4c8662a839 100644 >> > --- a/migration/migration.c >> > +++ b/migration/migration.c >> > @@ -3222,7 +3222,10 @@ static void migration_completion(MigrationState >> *s) >> > goto fail_invalidate; >> > } >> > >> > - if (!migrate_colo_enabled()) { >> > + if (migrate_colo_enabled()) { >> > + migrate_set_state(&s->state, current_active_state, >> > + MIGRATION_STATUS_COLO); >> > + } else { >> > migrate_set_state(&s->state, current_active_state, >> > MIGRATION_STATUS_COMPLETED); >> > } >> >> This moves the setup to MIGRATION_STATUS_COLO to completion time >> instead of the beggining of the process. I have no clue why. I guess you can >> put a comment/commit message to say what you ar.e trynig to do. > > You are right, no need to setup here. > I will remove this in next version. Thanks. >> > @@ -3607,12 +3610,7 @@ static void >> migration_iteration_finish(MigrationState *s) >> > migration_calculate_complete(s); >> > runstate_set(RUN_STATE_POSTMIGRATE); >> > break; >> > - >> > - case MIGRATION_STATUS_ACTIVE: >> > - /* >> > - * We should really assert here, but since it's during >> > - * migration, let's try to reduce the usage of assertions. >> > - */ >> > + case MIGRATION_STATUS_COLO: >> > if (!migrate_colo_enabled()) { >> > error_report("%s: critical error: calling COLO code without " >> > "COLO enabled", __func__); @@ -3622,6 >> > +3620,12 @@ static void migration_iteration_finish(MigrationState *s) >> > * Fixme: we will run VM in COLO no matter its old running state. >> > * After exited COLO, we will keep running. >> > */ >> > + /* Fallthrough */ >> > + case MIGRATION_STATUS_ACTIVE: >> > + /* >> > + * We should really assert here, but since it's during >> > + * migration, let's try to reduce the usage of assertions. >> > + */ >> > s->vm_was_running = true; >> > /* Fallthrough */ >> > case MIGRATION_STATUS_FAILED: >> >> I guess this change is related to the previous one, but I don't understand colo >> enough to review it. > > I think this patch is the general code, little background needed. > You can simple understand COLO is two VMs(primary node and secondary node) entered a state of cyclic migration. > Thanks your comments. Later, Juan.
diff --git a/migration/colo.c b/migration/colo.c index 2415325262..ad1a4426b3 100644 --- a/migration/colo.c +++ b/migration/colo.c @@ -667,8 +667,6 @@ void migrate_start_colo_process(MigrationState *s) colo_checkpoint_notify, s); qemu_sem_init(&s->colo_exit_sem, 0); - migrate_set_state(&s->state, MIGRATION_STATUS_ACTIVE, - MIGRATION_STATUS_COLO); colo_process_checkpoint(s); qemu_mutex_lock_iothread(); } diff --git a/migration/migration.c b/migration/migration.c index abaf6f9e3d..4c8662a839 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -3222,7 +3222,10 @@ static void migration_completion(MigrationState *s) goto fail_invalidate; } - if (!migrate_colo_enabled()) { + if (migrate_colo_enabled()) { + migrate_set_state(&s->state, current_active_state, + MIGRATION_STATUS_COLO); + } else { migrate_set_state(&s->state, current_active_state, MIGRATION_STATUS_COMPLETED); } @@ -3607,12 +3610,7 @@ static void migration_iteration_finish(MigrationState *s) migration_calculate_complete(s); runstate_set(RUN_STATE_POSTMIGRATE); break; - - case MIGRATION_STATUS_ACTIVE: - /* - * We should really assert here, but since it's during - * migration, let's try to reduce the usage of assertions. - */ + case MIGRATION_STATUS_COLO: if (!migrate_colo_enabled()) { error_report("%s: critical error: calling COLO code without " "COLO enabled", __func__); @@ -3622,6 +3620,12 @@ static void migration_iteration_finish(MigrationState *s) * Fixme: we will run VM in COLO no matter its old running state. * After exited COLO, we will keep running. */ + /* Fallthrough */ + case MIGRATION_STATUS_ACTIVE: + /* + * We should really assert here, but since it's during + * migration, let's try to reduce the usage of assertions. + */ s->vm_was_running = true; /* Fallthrough */ case MIGRATION_STATUS_FAILED:
There is no need to start COLO through MIGRATION_STATUS_ACTIVE. Signed-off-by: Zhang Chen <chen.zhang@intel.com> --- migration/colo.c | 2 -- migration/migration.c | 18 +++++++++++------- 2 files changed, 11 insertions(+), 9 deletions(-)