From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:34884) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gonak-0002o3-Uu for qemu-devel@nongnu.org; Wed, 30 Jan 2019 05:59:40 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gonaf-0004ZY-CK for qemu-devel@nongnu.org; Wed, 30 Jan 2019 05:59:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:35890) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gonaX-0004St-6k for qemu-devel@nongnu.org; Wed, 30 Jan 2019 05:59:29 -0500 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D7B49804F4 for ; Wed, 30 Jan 2019 10:59:21 +0000 (UTC) Date: Wed, 30 Jan 2019 10:59:10 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Message-ID: <20190130105910.GI15904@redhat.com> Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= References: <20190130103236.18302-1-dgilbert@redhat.com> <20190130103236.18302-3-dgilbert@redhat.com> <20190130104331.GG15904@redhat.com> <20190130105404.GA2677@work-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20190130105404.GA2677@work-vm> 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: "Dr. David Alan Gilbert" Cc: qemu-devel@nongnu.org, jasowang@redhat.com, quintela@redhat.com, mst@redhat.com, eblake@redhat.com, armbru@redhat.com, germano@redhat.com On Wed, Jan 30, 2019 at 10:54:04AM +0000, Dr. David Alan Gilbert wrote: > * Daniel P. Berrang=C3=A9 (berrange@redhat.com) wrote: > > On Wed, Jan 30, 2019 at 10:32:29AM +0000, Dr. David Alan Gilbert (git= ) wrote: > > > From: "Dr. David Alan Gilbert" > > >=20 > > > Add migration parameters that control RARP/GARP announcement timeou= ts. > > >=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 firs= t announce > > > +# (Since 4.0) > > > +# > > > +# @announce-max: Maximum delay (in ms) between packets in the anno= uncment > > > +# (Since 4.0) > > > +# > > > +# @announce-rounds: Number of self-announce packets sent after mig= ration > > > +# (Since 4.0) > > > +# > > > +# @announce-step: Increase in delay (in ms) between subsequent pac= kets 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, but > > 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 downsid= e > > I see is that for HMP it would need to be flattened to what it is her= e. > > 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 pretty > hairy. Yes, this different design would mean that the overall 'announce' parmaet= er was optional. If you did provide one of the parameters though, you would need to provide all 4 of them. I don't think that's a bad thing though, a= s the values really only make sense when considered as a whole. So setting one announce parameter without knowing what the other values are is somew= hat unreliable.=20 Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberran= ge :| |: https://libvirt.org -o- https://fstop138.berrange.c= om :| |: https://entangle-photo.org -o- https://www.instagram.com/dberran= ge :|