From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-comment-return-1428-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Date: Mon, 24 Aug 2020 17:19:35 +0200 From: Cornelia Huck Message-ID: <20200824171935.67055848.cohuck@redhat.com> In-Reply-To: <159827822200.192353.2054100263606468640.stgit@ahduyck-workstation> References: <159827814858.192353.8993077724330545555.stgit@ahduyck-workstation> <159827822200.192353.2054100263606468640.stgit@ahduyck-workstation> MIME-Version: 1.0 Subject: [virtio-comment] Re: [PATCH v7 1/3] content: Document balloon feature free page hints Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit To: Alexander Duyck Cc: mst@redhat.com, david@redhat.com, virtio-comment@lists.oasis-open.org, virtio-dev@lists.oasis-open.org, wei.w.wang@intel.com List-ID: On Mon, 24 Aug 2020 07:10:22 -0700 Alexander Duyck wrote: > From: Alexander Duyck > > Free page hints allow the balloon driver to provide information on what > pages are not currently in use so that we can avoid the cost of copying > them in migration scenarios. Add a feature description for free page hints > describing basic functioning and requirements. > > In working on this the specification as pointed out certain issues with the > Linux driver and QEMU device implementation. The issues include: > 1. The Linux driver does not re-initialize pages when it reuses them > before receiving the "DONE" command, as such this can lead to possible data > corruption. > 2. The QEMU device is not returning the "DONE" command if a migration > fails. This results in the guest holding onto pages until forced out by the > shrinker. > > There are also additional issues that have been found not related to the > specification. > > There is currently discussion on if the feature should be removed so this > patch is a place-holder for if we decide to keep the feature and fix the > issues. Otherwise this patch can be dropped and we can work on a patch to > document the need to avoid the feature. I think we should drop this paragraph? Otherwise, Acked-by: Cornelia Huck > > Reviewed-by: David Hildenbrand > Signed-off-by: Alexander Duyck > --- > conformance.tex | 2 + > content.tex | 161 +++++++++++++++++++++++++++++++++++++++++++++++++++++-- > 2 files changed, 157 insertions(+), 6 deletions(-) This publicly archived list offers a means to provide input to the OASIS Virtual I/O Device (VIRTIO) TC. In order to verify user consent to the Feedback License terms and to minimize spam in the list archive, subscription is required before posting. Subscribe: virtio-comment-subscribe@lists.oasis-open.org Unsubscribe: virtio-comment-unsubscribe@lists.oasis-open.org List help: virtio-comment-help@lists.oasis-open.org List archive: https://lists.oasis-open.org/archives/virtio-comment/ Feedback License: https://www.oasis-open.org/who/ipr/feedback_license.pdf List Guidelines: https://www.oasis-open.org/policies-guidelines/mailing-lists Committee: https://www.oasis-open.org/committees/virtio/ Join OASIS: https://www.oasis-open.org/join/