From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34715) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eWTzD-000673-1b for qemu-devel@nongnu.org; Tue, 02 Jan 2018 16:20:39 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eWTz8-00005y-QO for qemu-devel@nongnu.org; Tue, 02 Jan 2018 16:20:39 -0500 Received: from mx1.redhat.com ([209.132.183.28]:54946) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eWTz8-00005j-Fv for qemu-devel@nongnu.org; Tue, 02 Jan 2018 16:20:34 -0500 References: <1509369390-8285-1-git-send-email-a.perevalov@samsung.com> <1509369390-8285-2-git-send-email-a.perevalov@samsung.com> From: Eric Blake Message-ID: <6edfb28b-09fe-5fe9-7457-ed1cf1064a89@redhat.com> Date: Tue, 2 Jan 2018 15:20:28 -0600 MIME-Version: 1.0 In-Reply-To: <1509369390-8285-2-git-send-email-a.perevalov@samsung.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="3nAL2poncJxc1WI7Vfld3sPPov9fpQ5hp" Subject: Re: [Qemu-devel] [PATCH v12 1/6] migration: introduce postcopy-blocktime capability List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Perevalov , qemu-devel@nongnu.org Cc: heetae82.ahn@samsung.com, quintela@redhat.com, dgilbert@redhat.com, peterx@redhat.com, i.maximets@samsung.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --3nAL2poncJxc1WI7Vfld3sPPov9fpQ5hp From: Eric Blake To: Alexey Perevalov , qemu-devel@nongnu.org Cc: heetae82.ahn@samsung.com, quintela@redhat.com, dgilbert@redhat.com, peterx@redhat.com, i.maximets@samsung.com Message-ID: <6edfb28b-09fe-5fe9-7457-ed1cf1064a89@redhat.com> Subject: Re: [Qemu-devel] [PATCH v12 1/6] migration: introduce postcopy-blocktime capability References: <1509369390-8285-1-git-send-email-a.perevalov@samsung.com> <1509369390-8285-2-git-send-email-a.perevalov@samsung.com> In-Reply-To: <1509369390-8285-2-git-send-email-a.perevalov@samsung.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 10/30/2017 08:16 AM, Alexey Perevalov wrote: > Right now it could be used on destination side to > enable vCPU blocktime calculation for postcopy live migration. > vCPU blocktime - it's time since vCPU thread was put into > interruptible sleep, till memory page was copied and thread awake. >=20 > Reviewed-by: Dr. David Alan Gilbert > Signed-off-by: Alexey Perevalov > --- > migration/migration.c | 9 +++++++++ > migration/migration.h | 1 + > qapi/migration.json | 6 +++++- > 3 files changed, 15 insertions(+), 1 deletion(-) >=20 Is there any reason this has to be a new capability rather than unconditionally enabled? What are the trade-offs for enabling vs. disabling the capability that warrant it being a knob? Can we do a better job of documenting in which cases the user would want to change the knob from its default value, if we even need it to be a knob? > +++ b/qapi/migration.json > @@ -352,12 +352,16 @@ > # > # @x-multifd: Use more than one fd for migration (since 2.11) > # > +# @postcopy-blocktime: Calculate downtime for postcopy live migration > +# (since 2.11) > +# > # Since: 1.2 > ## > { 'enum': 'MigrationCapability', > 'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks', > 'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ra= m', > - 'block', 'return-path', 'pause-before-switchover', 'x-multi= fd' ] } > + 'block', 'return-path', 'pause-before-switchover', 'x-multi= fd', > + 'postcopy-blocktime' ] } > =20 > ## > # @MigrationCapabilityStatus: >=20 --=20 Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org --3nAL2poncJxc1WI7Vfld3sPPov9fpQ5hp Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Comment: Public key at http://people.redhat.com/eblake/eblake.gpg Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEzBAEBCAAdFiEEccLMIrHEYCkn0vOqp6FrSiUnQ2oFAlpL95wACgkQp6FrSiUn Q2p1QQgAksCbwnkYSj+p0MmMKByzfi2tJSOstByU1KPcu+7GweeqkppjQW7jL619 wxa237APox6XQtQjNFYJ1/+Qpoq0tqohq0pKE8Mc/YdxdJBqlckHtgeBBQw5jBbk 3Xwy4xDP8RuOIHpgY8bqC0DPRksdQQsOZQjcAsXfConFdbplDcxbCR8cwqo7S2Uu F8Rb+YUoL0OpKUF9pIj3rLTvM0FN6irNn8UGPlDwBcbGewislLGwKcCmcBCGedOi 51UYHVc9Z90jLHBDsRb93B/QJ29XjntFjrBzjdA5GxZZtauZPXrLsJjtonbuuJQl gdMo9PwXnfTPIaiVzC0H7hOniCLHuA== =2YbS -----END PGP SIGNATURE----- --3nAL2poncJxc1WI7Vfld3sPPov9fpQ5hp--