From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:48450) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gooZD-0006Cx-72 for qemu-devel@nongnu.org; Wed, 30 Jan 2019 07:02:08 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gooZ7-000100-6U for qemu-devel@nongnu.org; Wed, 30 Jan 2019 07:02:07 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33260) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gooZ5-0000yw-9q for qemu-devel@nongnu.org; Wed, 30 Jan 2019 07:01:59 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B4ED18553D for ; Wed, 30 Jan 2019 12:01:57 +0000 (UTC) Date: Wed, 30 Jan 2019 12:01:46 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20190130120145.GC2677@work-vm> References: <20190130103236.18302-1-dgilbert@redhat.com> <20190130103236.18302-3-dgilbert@redhat.com> <20190130104331.GG15904@redhat.com> <20190130105404.GA2677@work-vm> <20190130105910.GI15904@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20190130105910.GI15904@redhat.com> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH v2 2/9] migration: Add announce parameters List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= Cc: qemu-devel@nongnu.org, jasowang@redhat.com, quintela@redhat.com, mst@redhat.com, eblake@redhat.com, armbru@redhat.com, germano@redhat.com * Daniel P. Berrang=E9 (berrange@redhat.com) wrote: > On Wed, Jan 30, 2019 at 10:54:04AM +0000, Dr. David Alan Gilbert wrote: > > * Daniel P. Berrang=E9 (berrange@redhat.com) wrote: > > > On Wed, Jan 30, 2019 at 10:32:29AM +0000, Dr. David Alan Gilbert (g= it) wrote: > > > > From: "Dr. David Alan Gilbert" > > > >=20 > > > > Add migration parameters that control RARP/GARP announcement time= outs. > > > >=20 > > > > Based on earlier patches by myself and > > > > Vladislav Yasevich > > > >=20 > > > > Signed-off-by: Dr. David Alan Gilbert > > > > --- > > > > hmp.c | 28 +++++++++++ > > > > include/migration/misc.h | 2 + > > > > include/qemu/typedefs.h | 1 + > > > > migration/migration.c | 100 +++++++++++++++++++++++++++++++++= ++++++ > > > > qapi/migration.json | 54 +++++++++++++++++++-- > > > > 5 files changed, 182 insertions(+), 3 deletions(-) > > > >=20 > > > > diff --git a/qapi/migration.json b/qapi/migration.json > > > > index 7a795ecc16..113bb5d925 100644 > > > > --- a/qapi/migration.json > > > > +++ b/qapi/migration.json > > > > @@ -6,6 +6,7 @@ > > > > ## > > > > =20 > > > > { 'include': 'common.json' } > > > > +{ 'include': 'net.json' } > > >=20 > > >=20 > > > > @@ -572,6 +588,18 @@ > > > > ## > > > > # @MigrateSetParameters: > > > > # > > > > +# @announce-initial: Initial delay (in ms) before sending the fi= rst announce > > > > +# (Since 4.0) > > > > +# > > > > +# @announce-max: Maximum delay (in ms) between packets in the an= nouncment > > > > +# (Since 4.0) > > > > +# > > > > +# @announce-rounds: Number of self-announce packets sent after m= igration > > > > +# (Since 4.0) > > > > +# > > > > +# @announce-step: Increase in delay (in ms) between subsequent p= ackets in > > > > +# the announcement (Since 4.0) > > > > +# > > > > # @compress-level: compression level > > > > # > > > > # @compress-threads: compression thread count > > > > @@ -653,7 +681,11 @@ > > > > # TODO either fuse back into MigrationParameters, or make > > > > # MigrationParameters members mandatory > > > > { 'struct': 'MigrateSetParameters', > > > > - 'data': { '*compress-level': 'int', > > > > + 'data': { '*announce-initial': 'size', > > > > + '*announce-max': 'size', > > > > + '*announce-rounds': 'size', > > > > + '*announce-step': 'size', > > > > + '*compress-level': 'int', > > > > '*compress-threads': 'int', > > > > '*compress-wait-thread': 'bool', > > > > '*decompress-threads': 'int', > > >=20 > > > Historically we've just had a flat list of migration parameters, bu= t > > > QAPI doesn't require this. So I wonder about just referencing the > > > type you defined in the previous patch: > > >=20 > > > '*announce': 'AnnounceParameters > > >=20 > > > from a QMP pov this is trivial & feels more natural. The only downs= ide > > > I see is that for HMP it would need to be flattened to what it is h= ere. > > > We generally tend to prefer QMP's natural style, even if it doesn't > > > match what's nicest for HMP. > >=20 > > I don't trust that's true from QMP; the logic to keep the parameters > > optional so that you can set a parameter individually is already pret= ty > > hairy. >=20 > Yes, this different design would mean that the overall 'announce' parma= eter > was optional. If you did provide one of the parameters though, you woul= d > need to provide all 4 of them. I don't think that's a bad thing though,= as > the values really only make sense when considered as a whole. So settin= g > one announce parameter without knowing what the other values are is som= ewhat > unreliable.=20 Actually, some of them make a lot of sense; for example just setting 'rounds' to 0 to stop any announce works really well, or doubling it if you want to keep it shouting longer; my suspicion is that very few people would fiddle with anything except 'rounds'. Dave >=20 > Regards, > Daniel > --=20 > |: https://berrange.com -o- https://www.flickr.com/photos/dberr= ange :| > |: https://libvirt.org -o- https://fstop138.berrange= .com :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberr= ange :| -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK