From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60507) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dcFny-0005rD-R0 for qemu-devel@nongnu.org; Mon, 31 Jul 2017 14:52:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dcFnt-0001ef-Sq for qemu-devel@nongnu.org; Mon, 31 Jul 2017 14:52:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57724) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dcFnt-0001eP-JZ for qemu-devel@nongnu.org; Mon, 31 Jul 2017 14:52:33 -0400 Date: Mon, 31 Jul 2017 19:52:24 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20170731185224.GB3095@work-vm> References: <1501229198-30588-1-git-send-email-peterx@redhat.com> <1501229198-30588-11-git-send-email-peterx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1501229198-30588-11-git-send-email-peterx@redhat.com> Subject: Re: [Qemu-devel] [RFC 10/29] migration: new property "x-postcopy-fast" 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 provides a way to start postcopy ASAP when migration starts. To do > this, we need both: > > -global migration.x-postcopy-ram=on \ > -global migration.x-postcopy-fast=on Can you explain why this is necessary? Both sides already know they're doing a postcopy recovery don't they? Dave > > Signed-off-by: Peter Xu > --- > migration/migration.c | 9 ++++++++- > migration/migration.h | 2 ++ > 2 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/migration/migration.c b/migration/migration.c > index 5b2602e..efee87e 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -1936,6 +1936,11 @@ bool migrate_colo_enabled(void) > return s->enabled_capabilities[MIGRATION_CAPABILITY_X_COLO]; > } > > +static bool postcopy_should_start(MigrationState *s) > +{ > + return atomic_read(&s->start_postcopy) || s->start_postcopy_fast; > +} > + > /* > * Master migration thread on the source VM. > * It drives the migration and pumps the data down the outgoing channel. > @@ -2013,7 +2018,7 @@ static void *migration_thread(void *opaque) > if (migrate_postcopy_ram() && > s->state != MIGRATION_STATUS_POSTCOPY_ACTIVE && > pend_nonpost <= threshold_size && > - atomic_read(&s->start_postcopy)) { > + postcopy_should_start(s)) { > > if (!postcopy_start(s, &old_vm_running)) { > current_active_state = MIGRATION_STATUS_POSTCOPY_ACTIVE; > @@ -2170,6 +2175,8 @@ static Property migration_properties[] = { > send_configuration, true), > DEFINE_PROP_BOOL("send-section-footer", MigrationState, > send_section_footer, true), > + DEFINE_PROP_BOOL("x-postcopy-fast", MigrationState, > + start_postcopy_fast, false), > > /* Migration parameters */ > DEFINE_PROP_INT64("x-compress-level", MigrationState, > diff --git a/migration/migration.h b/migration/migration.h > index 70e3094..e902bae 100644 > --- a/migration/migration.h > +++ b/migration/migration.h > @@ -113,6 +113,8 @@ struct MigrationState > > /* Flag set once the migration has been asked to enter postcopy */ > bool start_postcopy; > + /* Set the flag if we want to start postcopy ASAP when migration starts */ > + bool start_postcopy_fast; > /* Flag set after postcopy has sent the device state */ > bool postcopy_after_devices; > > -- > 2.7.4 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK