From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jason Wang <jasowang@redhat.com>
Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
wexu@redhat.com, jfreimann@redhat.com, tiwei.bie@intel.com,
maxime.coquelin@redhat.com
Subject: Re: [PATCH net-next V2 0/8] Packed virtqueue support for vhost
Date: Mon, 16 Jul 2018 11:39:11 +0300 [thread overview]
Message-ID: <20180716113720-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <1531711691-6769-1-git-send-email-jasowang@redhat.com>
On Mon, Jul 16, 2018 at 11:28:03AM +0800, Jason Wang wrote:
> Hi all:
>
> This series implements packed virtqueues. The code were tested with
> Tiwei's guest driver series at https://patchwork.ozlabs.org/cover/942297/
>
>
> Pktgen test for both RX and TX does not show obvious difference with
> split virtqueues. The main bottleneck is the guest Linux driver, since
> it can not stress vhost for a 100% CPU utilization. A full TCP
> benchmark is ongoing. Will test virtio-net pmd as well when it was
> ready.
Well the question then is why we should bother merging this
if this doesn't give a performance gain. Do you see
a gain in CPU utilization maybe?
If not - let's wait for that TCP benchmark result?
> Notes:
> - This version depends on Tiwei's series at https://patchwork.ozlabs.org/cover/942297/
>
> This version were tested with:
>
> - Zerocopy (Out of Order) support
> - vIOMMU support
> - mergeable buffer on/off
> - busy polling on/off
> - vsock (nc-vsock)
>
> Changes from V1:
> - drop uapi patch and use Tiwei's
> - split the enablement of packed virtqueue into a separate patch
>
> Changes from RFC V5:
>
> - save unnecessary barriers during vhost_add_used_packed_n()
> - more compact math for event idx
> - fix failure of SET_VRING_BASE when avail_wrap_counter is true
> - fix not copy avail_wrap_counter during GET_VRING_BASE
> - introduce SET_VRING_USED_BASE/GET_VRING_USED_BASE for syncing last_used_idx
> - rename used_wrap_counter to last_used_wrap_counter
> - rebase to net-next
>
> Changes from RFC V4:
>
> - fix signalled_used index recording
> - track avail index correctly
> - various minor fixes
>
> Changes from RFC V3:
>
> - Fix math on event idx checking
> - Sync last avail wrap counter through GET/SET_VRING_BASE
> - remove desc_event prefix in the driver/device structure
>
> Changes from RFC V2:
>
> - do not use & in checking desc_event_flags
> - off should be most significant bit
> - remove the workaround of mergeable buffer for dpdk prototype
> - id should be in the last descriptor in the chain
> - keep _F_WRITE for write descriptor when adding used
> - device flags updating should use ADDR_USED type
> - return error on unexpected unavail descriptor in a chain
> - return false in vhost_ve_avail_empty is descriptor is available
> - track last seen avail_wrap_counter
> - correctly examine available descriptor in get_indirect_packed()
> - vhost_idx_diff should return u16 instead of bool
>
> Changes from RFC V1:
>
> - Refactor vhost used elem code to avoid open coding on used elem
> - Event suppression support (compile test only).
> - Indirect descriptor support (compile test only).
> - Zerocopy support.
> - vIOMMU support.
> - SCSI/VSOCK support (compile test only).
> - Fix several bugs
>
> Jason Wang (8):
> vhost: move get_rx_bufs to vhost.c
> vhost: hide used ring layout from device
> vhost: do not use vring_used_elem
> vhost_net: do not explicitly manipulate vhost_used_elem
> vhost: vhost_put_user() can accept metadata type
> vhost: packed ring support
> vhost: event suppression for packed ring
> vhost: enable packed virtqueues
>
> drivers/vhost/net.c | 143 ++-----
> drivers/vhost/scsi.c | 62 +--
> drivers/vhost/vhost.c | 994 ++++++++++++++++++++++++++++++++++++++++-----
> drivers/vhost/vhost.h | 55 ++-
> drivers/vhost/vsock.c | 42 +-
> include/uapi/linux/vhost.h | 7 +
> 6 files changed, 1035 insertions(+), 268 deletions(-)
>
> --
> 2.7.4
next prev parent reply other threads:[~2018-07-16 8:39 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-16 3:28 [PATCH net-next V2 0/8] Packed virtqueue support for vhost Jason Wang
2018-07-16 3:28 ` [PATCH net-next V2 1/8] vhost: move get_rx_bufs to vhost.c Jason Wang
2018-07-16 3:28 ` [PATCH net-next V2 2/8] vhost: hide used ring layout from device Jason Wang
2018-07-16 3:28 ` [PATCH net-next V2 3/8] vhost: do not use vring_used_elem Jason Wang
2018-07-16 3:28 ` [PATCH net-next V2 4/8] vhost_net: do not explicitly manipulate vhost_used_elem Jason Wang
2018-07-16 3:28 ` [PATCH net-next V2 5/8] vhost: vhost_put_user() can accept metadata type Jason Wang
2018-07-16 3:28 ` [PATCH net-next V2 6/8] vhost: packed ring support Jason Wang
2018-10-12 14:32 ` Tiwei Bie
2018-10-12 17:23 ` Michael S. Tsirkin
2018-10-15 2:22 ` Jason Wang
2018-10-15 2:43 ` Michael S. Tsirkin
2018-10-15 2:51 ` Jason Wang
2018-10-15 10:25 ` Michael S. Tsirkin
2018-10-18 2:44 ` Jason Wang
2018-10-16 13:58 ` Maxime Coquelin
2018-10-17 6:54 ` Jason Wang
2018-10-17 12:02 ` Maxime Coquelin
2018-07-16 3:28 ` [PATCH net-next V2 7/8] vhost: event suppression for packed ring Jason Wang
2018-07-16 3:28 ` [PATCH net-next V2 8/8] vhost: enable packed virtqueues Jason Wang
2018-07-16 8:39 ` Michael S. Tsirkin [this message]
2018-07-16 9:46 ` [PATCH net-next V2 0/8] Packed virtqueue support for vhost Jason Wang
2018-07-16 12:49 ` Michael S. Tsirkin
2018-07-17 0:45 ` Jason Wang
2018-07-22 16:56 ` Michael S. Tsirkin
2018-07-18 4:09 ` David Miller
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