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From: "Michael S. Tsirkin" <mst@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
	netdev@vger.kernel.org, Jason Wang <jasowang@redhat.com>
Subject: [PATCH RFC v2 0/2] vhost: ring format independence
Date: Sat, 12 Oct 2019 15:18:44 -0400
Message-ID: <20191012191820.8050-1-mst@redhat.com> (raw)

This adds infrastructure required for supporting
multiple ring formats.

The idea is as follows: we convert descriptors to an
independent format first, and process that converting to
iov later.

The point is that we have a tight loop that fetches
descriptors, which is good for cache utilization.
This will also allow all kind of batching tricks -
e.g. it seems possible to keep SMAP disabled while
we are fetching multiple descriptors.

This seems to perform exactly the same as the original
code already based on a microbenchmark.
More testing would be very much appreciated.

Biggest TODO before this first step is ready to go in is to
batch indirect descriptors as well.

Integrating into vhost-net is basically
s/vhost_get_vq_desc/vhost_get_vq_desc_batch/ -
or add a module parameter like I did in the test module.

Changes from v1:
	- typo fixes

Michael S. Tsirkin (2):
  vhost: option to fetch descriptors through an independent struct
  vhost: batching fetches

 drivers/vhost/test.c  |  19 ++-
 drivers/vhost/vhost.c | 333 +++++++++++++++++++++++++++++++++++++++++-
 drivers/vhost/vhost.h |  20 ++-
 3 files changed, 365 insertions(+), 7 deletions(-)


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Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-12 19:18 Michael S. Tsirkin [this message]
2019-10-12 19:18 ` [PATCH RFC v2 1/2] vhost: option to fetch descriptors through an independent struct Michael S. Tsirkin
2019-10-12 19:18 ` [PATCH RFC v2 2/2] vhost: batching fetches Michael S. Tsirkin

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