From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: xuan.ding@intel.com, chenbo.xia@intel.com
Cc: dev@dpdk.org, jiayu.hu@intel.com, sunil.pai.g@intel.com
Subject: Re: [RFC 1/2] vhost: add unsafe API to check inflight packets
Date: Mon, 28 Mar 2022 17:05:20 +0200 [thread overview]
Message-ID: <010d6382-866e-2492-b4f2-3825adeadf2b@redhat.com> (raw)
In-Reply-To: <20220216070417.9597-2-xuan.ding@intel.com>
Hi Xuan,
On 2/16/22 08:04, xuan.ding@intel.com wrote:
> From: Xuan Ding <xuan.ding@intel.com>
>
> In async data path, when vring state changes or device is destroyed,
> it is necessary to know the number of inflight packets in DMA engine.
> This patch provides a thread unsafe API to return the number of
> inflight packets for a vhost queue without using any lock.
>
> Signed-off-by: Xuan Ding <xuan.ding@intel.com>
> ---
> doc/guides/prog_guide/vhost_lib.rst | 5 +++++
> doc/guides/rel_notes/release_22_03.rst | 4 ++++
> lib/vhost/rte_vhost_async.h | 14 ++++++++++++++
> lib/vhost/version.map | 1 +
> lib/vhost/vhost.c | 26 ++++++++++++++++++++++++++
> 5 files changed, 50 insertions(+)
>
> diff --git a/doc/guides/prog_guide/vhost_lib.rst b/doc/guides/prog_guide/vhost_lib.rst
> index 886f8f5e72..f95288d128 100644
> --- a/doc/guides/prog_guide/vhost_lib.rst
> +++ b/doc/guides/prog_guide/vhost_lib.rst
> @@ -271,6 +271,11 @@ The following is an overview of some key Vhost API functions:
> This function returns the amount of in-flight packets for the vhost
> queue using async acceleration.
>
> + * ``rte_vhost_async_get_inflight_thread_unsafe(vid, queue_id)``
> +
> + Get the number of inflight packets for a vhost queue without
> + performing any locking.
Here and below in the API doc, I would add that it should only be used
within the vhost ops, which already hold the lock.
> +
> * ``rte_vhost_clear_queue_thread_unsafe(vid, queue_id, **pkts, count, dma_id, vchan_id)``
>
> Clear inflight packets which are submitted to DMA engine in vhost async data
> diff --git a/doc/guides/rel_notes/release_22_03.rst b/doc/guides/rel_notes/release_22_03.rst
> index ff3095d742..37ef37bb20 100644
> --- a/doc/guides/rel_notes/release_22_03.rst
> +++ b/doc/guides/rel_notes/release_22_03.rst
> @@ -149,6 +149,10 @@ New Features
> * Called ``rte_ipv4/6_udptcp_cksum_mbuf()`` functions in testpmd csum mode
> to support software UDP/TCP checksum over multiple segments.
>
> +* **Added vhost API to get the number of inflight packets.**
> +
> + Added an API which can get the number of inflight packets in
> + vhost async data path without using lock.
>
> Removed Items
> -------------
> diff --git a/lib/vhost/rte_vhost_async.h b/lib/vhost/rte_vhost_async.h
> index 838c4778cc..06b0b0a579 100644
> --- a/lib/vhost/rte_vhost_async.h
> +++ b/lib/vhost/rte_vhost_async.h
> @@ -135,6 +135,20 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
> __rte_experimental
> int rte_vhost_async_get_inflight(int vid, uint16_t queue_id);
>
> +/**
> + * This function is lock-free version to return the amount of in-flight
> + * packets for the vhost queue which uses async channel acceleration.
> + *
> + * @param vid
> + * id of vhost device to enqueue data
> + * @param queue_id
> + * queue id to enqueue data
> + * @return
> + * the amount of in-flight packets on success; -1 on failure
> + */
> +__rte_experimental
> +int rte_vhost_async_get_inflight_thread_unsafe(int vid, uint16_t queue_id);
> +
> /**
> * This function checks async completion status and clear packets for
> * a specific vhost device queue. Packets which are inflight will be
> diff --git a/lib/vhost/version.map b/lib/vhost/version.map
> index 1202ba9c1a..03b46cb10e 100644
> --- a/lib/vhost/version.map
> +++ b/lib/vhost/version.map
> @@ -87,6 +87,7 @@ EXPERIMENTAL {
>
> # added in 22.03
> rte_vhost_async_dma_configure;
> + rte_vhost_async_get_inflight_thread_unsafe;
Don't forget to move it to "added in 22.07".
> };
>
> INTERNAL {
> diff --git a/lib/vhost/vhost.c b/lib/vhost/vhost.c
> index 6bcb716de0..33dca62c6c 100644
> --- a/lib/vhost/vhost.c
> +++ b/lib/vhost/vhost.c
> @@ -1907,6 +1907,32 @@ rte_vhost_async_get_inflight(int vid, uint16_t queue_id)
> return ret;
> }
>
> +int
> +rte_vhost_async_get_inflight_thread_unsafe(int vid, uint16_t queue_id)
> +{
> + struct vhost_virtqueue *vq;
> + struct virtio_net *dev = get_device(vid);
> + int ret = -1;
> +
> + if (dev == NULL)
> + return ret;
> +
> + if (queue_id >= VHOST_MAX_VRING)
> + return ret;
> +
> + vq = dev->virtqueue[queue_id];
> +
> + if (vq == NULL)
> + return ret;
> +
> + if (!vq->async)
> + return ret;
> +
> + ret = vq->async->pkts_inflight_n;
> +
> + return ret;
> +}
> +
> int
> rte_vhost_get_monitor_addr(int vid, uint16_t queue_id,
> struct rte_vhost_power_monitor_cond *pmc)
next prev parent reply other threads:[~2022-03-28 15:05 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-16 7:04 [RFC 0/2] add unsafe API to get " xuan.ding
2022-02-16 7:04 ` [RFC 1/2] vhost: add unsafe API to check " xuan.ding
2022-03-28 15:05 ` Maxime Coquelin [this message]
2022-03-29 2:21 ` Ding, Xuan
2022-02-16 7:04 ` [RFC 2/2] examples/vhost: use " xuan.ding
2022-03-28 15:19 ` Maxime Coquelin
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