From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39597) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ddGaO-0003A5-Cw for qemu-devel@nongnu.org; Thu, 03 Aug 2017 09:54:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ddGaJ-0007NE-Px for qemu-devel@nongnu.org; Thu, 03 Aug 2017 09:54:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47644) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ddGaJ-0007Lv-Gn for qemu-devel@nongnu.org; Thu, 03 Aug 2017 09:54:43 -0400 Date: Thu, 3 Aug 2017 14:54:35 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20170803135434.GB3673@work-vm> References: <1501229198-30588-1-git-send-email-peterx@redhat.com> <1501229198-30588-30-git-send-email-peterx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1501229198-30588-30-git-send-email-peterx@redhat.com> Subject: Re: [Qemu-devel] [RFC 29/29] migration: reset migrate thread vars when resumed List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Xu Cc: qemu-devel@nongnu.org, Laurent Vivier , Alexey Perevalov , Juan Quintela , Andrea Arcangeli * Peter Xu (peterx@redhat.com) wrote: > Firstly, MigThrError enumeration is introduced to describe the error in > migration_detect_error() better. This gives the migration_thread() a > chance to know whether a recovery has happened. > > Then, if a recovery is detected, migration_thread() will reset its local > variables to prepare for that. > > Signed-off-by: Peter Xu > --- > migration/migration.c | 40 +++++++++++++++++++++++++++++----------- > 1 file changed, 29 insertions(+), 11 deletions(-) > > diff --git a/migration/migration.c b/migration/migration.c > index ecebe30..439bc22 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -2159,6 +2159,15 @@ static bool postcopy_should_start(MigrationState *s) > return atomic_read(&s->start_postcopy) || s->start_postcopy_fast; > } > > +typedef enum MigThrError { > + /* No error detected */ > + MIG_THR_ERR_NONE = 0, > + /* Detected error, but resumed successfully */ > + MIG_THR_ERR_RECOVERED = 1, > + /* Detected fatal error, need to exit */ > + MIG_THR_ERR_FATAL = 2, > +} MigThrError; > + Could you move this patch earlier to when postcopy_pause is created so it's created with this enum? > static int postcopy_resume_handshake(MigrationState *s) > { > qemu_mutex_lock(&s->resume_lock); > @@ -2209,10 +2218,10 @@ static int postcopy_do_resume(MigrationState *s) > > /* > * We don't return until we are in a safe state to continue current > - * postcopy migration. Returns true to continue the migration, or > - * false to terminate current migration. > + * postcopy migration. Returns MIG_THR_ERR_RECOVERED if recovered, or > + * MIG_THR_ERR_FATAL if unrecovery failure happened. > */ > -static bool postcopy_pause(MigrationState *s) > +static MigThrError postcopy_pause(MigrationState *s) > { > assert(s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE); > > @@ -2247,7 +2256,7 @@ do_pause: > if (postcopy_do_resume(s) == 0) { > /* Let's continue! */ > trace_postcopy_pause_continued(); > - return true; > + return MIG_THR_ERR_RECOVERED; > } else { > /* > * Something wrong happened during the recovery, let's > @@ -2258,12 +2267,11 @@ do_pause: > } > } else { > /* This is not right... Time to quit. */ > - return false; > + return MIG_THR_ERR_FATAL; > } > } > > -/* Return true if we want to stop the migration, otherwise false. */ > -static bool migration_detect_error(MigrationState *s) > +static MigThrError migration_detect_error(MigrationState *s) > { > int ret; > > @@ -2272,7 +2280,7 @@ static bool migration_detect_error(MigrationState *s) > > if (!ret) { > /* Everything is fine */ > - return false; > + return MIG_THR_ERR_NONE; > } > > if (s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE && ret == -EIO) { > @@ -2281,7 +2289,7 @@ static bool migration_detect_error(MigrationState *s) > * while. After that, it can be continued by a > * recovery phase. > */ > - return !postcopy_pause(s); > + return postcopy_pause(s); > } else { > /* > * For precopy (or postcopy with error outside IO), we fail > @@ -2291,7 +2299,7 @@ static bool migration_detect_error(MigrationState *s) > trace_migration_thread_file_err(); > > /* Time to stop the migration, now. */ > - return true; > + return MIG_THR_ERR_FATAL; > } > } > > @@ -2319,6 +2327,7 @@ static void *migration_thread(void *opaque) > /* The active state we expect to be in; ACTIVE or POSTCOPY_ACTIVE */ > enum MigrationStatus current_active_state = MIGRATION_STATUS_ACTIVE; > bool enable_colo = migrate_colo_enabled(); > + MigThrError thr_error; > > rcu_register_thread(); > > @@ -2395,8 +2404,17 @@ static void *migration_thread(void *opaque) > * Try to detect any kind of failures, and see whether we > * should stop the migration now. > */ > - if (migration_detect_error(s)) { > + thr_error = migration_detect_error(s); > + if (thr_error == MIG_THR_ERR_FATAL) { > + /* Stop migration */ > break; > + } else if (thr_error == MIG_THR_ERR_RECOVERED) { > + /* > + * Just recovered from a e.g. network failure, reset all > + * the local variables. > + */ > + initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); > + initial_bytes = 0; They don't seem that important to reset? Dave > } > > current_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); > -- > 2.7.4 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK