From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34741) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dcUtS-0001g2-Lw for qemu-devel@nongnu.org; Tue, 01 Aug 2017 06:59:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dcUtO-0000gg-IR for qemu-devel@nongnu.org; Tue, 01 Aug 2017 06:59:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40002) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dcUtO-0000gN-9E for qemu-devel@nongnu.org; Tue, 01 Aug 2017 06:59:14 -0400 Date: Tue, 1 Aug 2017 11:59:07 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20170801105906.GJ2079@work-vm> References: <1501229198-30588-1-git-send-email-peterx@redhat.com> <1501229198-30588-18-git-send-email-peterx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1501229198-30588-18-git-send-email-peterx@redhat.com> Subject: Re: [Qemu-devel] [RFC 17/29] migration: rebuild channel on source 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: > This patch detects the "resume" flag of migration command, rebuild the > channels only if the flag is set. > > Signed-off-by: Peter Xu > --- > migration/migration.c | 52 ++++++++++++++++++++++++++++++++++++++++----------- > 1 file changed, 41 insertions(+), 11 deletions(-) > > diff --git a/migration/migration.c b/migration/migration.c > index 36ff8c3..64de0ee 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -1244,6 +1244,15 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk, > MigrationState *s = migrate_get_current(); > const char *p; > > + if (has_resume && resume) { > + if (s->state != MIGRATION_STATUS_POSTCOPY_PAUSED) { > + error_setg(errp, "Cannot resume if there is no " > + "paused migration"); > + return; > + } > + goto do_resume; > + } > + > if (migration_is_setup_or_active(s->state) || > s->state == MIGRATION_STATUS_CANCELLING || > s->state == MIGRATION_STATUS_COLO) { > @@ -1279,6 +1288,7 @@ void qmp_migrate(const char *uri, bool has_blk, bool blk, > > s = migrate_init(); > > +do_resume: Can we find a way to avoid this label? Perhaps split the bottom half of this function out into a separate function? Dave > if (strstart(uri, "tcp:", &p)) { > tcp_start_outgoing_migration(s, p, &local_err); > #ifdef CONFIG_RDMA > @@ -1700,7 +1710,8 @@ out: > return NULL; > } > > -static int open_return_path_on_source(MigrationState *ms) > +static int open_return_path_on_source(MigrationState *ms, > + bool create_thread) > { > > ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file); > @@ -1709,6 +1720,12 @@ static int open_return_path_on_source(MigrationState *ms) > } > > trace_open_return_path_on_source(); > + > + if (!create_thread) { > + /* We're done */ > + return 0; > + } > + > qemu_thread_create(&ms->rp_state.rp_thread, "return path", > source_return_path_thread, ms, QEMU_THREAD_JOINABLE); > > @@ -2249,15 +2266,24 @@ static void *migration_thread(void *opaque) > > void migrate_fd_connect(MigrationState *s) > { > - s->expected_downtime = s->parameters.downtime_limit; > - s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s); > + int64_t rate_limit; > + bool resume = s->state == MIGRATION_STATUS_POSTCOPY_PAUSED; > > - qemu_file_set_blocking(s->to_dst_file, true); > - qemu_file_set_rate_limit(s->to_dst_file, > - s->parameters.max_bandwidth / XFER_LIMIT_RATIO); > + if (resume) { > + /* This is a resumed migration */ > + rate_limit = INT64_MAX; > + } else { > + /* This is a fresh new migration */ > + rate_limit = s->parameters.max_bandwidth / XFER_LIMIT_RATIO; > + s->expected_downtime = s->parameters.downtime_limit; > + s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s); > > - /* Notify before starting migration thread */ > - notifier_list_notify(&migration_state_notifiers, s); > + /* Notify before starting migration thread */ > + notifier_list_notify(&migration_state_notifiers, s); > + } > + > + qemu_file_set_rate_limit(s->to_dst_file, rate_limit); > + qemu_file_set_blocking(s->to_dst_file, true); > > /* > * Open the return path. For postcopy, it is used exclusively. For > @@ -2265,15 +2291,19 @@ void migrate_fd_connect(MigrationState *s) > * QEMU uses the return path. > */ > if (migrate_postcopy_ram() || migrate_use_return_path()) { > - if (open_return_path_on_source(s)) { > + if (open_return_path_on_source(s, !resume)) { > error_report("Unable to open return-path for postcopy"); > - migrate_set_state(&s->state, MIGRATION_STATUS_SETUP, > - MIGRATION_STATUS_FAILED); > + migrate_set_state(&s->state, s->state, MIGRATION_STATUS_FAILED); > migrate_fd_cleanup(s); > return; > } > } > > + if (resume) { > + /* TODO: do the resume logic */ > + return; > + } > + > qemu_thread_create(&s->thread, "live_migration", migration_thread, s, > QEMU_THREAD_JOINABLE); > s->migration_thread_running = true; > -- > 2.7.4 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK