diff mbox series

[v5,2/2] examples/vhost: use API to check inflight packets

Message ID 20210928062446.101264-3-xuan.ding@intel.com (mailing list archive)
State Superseded, archived
Delegated to: Maxime Coquelin
Headers
Series add unsafe API to get inflight packets |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/github-robot: build success github build: passed
ci/Intel-compilation success Compilation OK
ci/intel-Testing success Testing PASS

Commit Message

Ding, Xuan Sept. 28, 2021, 6:24 a.m. UTC 
  In async data path, call rte_vhost_async_get_inflight_thread_unsafe()
API to directly return the number of inflight packets instead of
maintaining a local variable.

Signed-off-by: Xuan Ding <xuan.ding@intel.com>
---
 examples/vhost/main.c | 25 +++++++++++--------------
 examples/vhost/main.h |  1 -
 2 files changed, 11 insertions(+), 15 deletions(-)

Comments

Kevin Traynor Sept. 28, 2021, 9:17 a.m. UTC | #1 
On 28/09/2021 07:24, Xuan Ding wrote:
> In async data path, call rte_vhost_async_get_inflight_thread_unsafe()
> API to directly return the number of inflight packets instead of
> maintaining a local variable.
> 
> Signed-off-by: Xuan Ding <xuan.ding@intel.com>
> ---
>   examples/vhost/main.c | 25 +++++++++++--------------
>   examples/vhost/main.h |  1 -
>   2 files changed, 11 insertions(+), 15 deletions(-)
> 
> diff --git a/examples/vhost/main.c b/examples/vhost/main.c
> index d0bf1f31e3..3faac6d053 100644
> --- a/examples/vhost/main.c
> +++ b/examples/vhost/main.c
> @@ -842,11 +842,8 @@ complete_async_pkts(struct vhost_dev *vdev)
>   
>   	complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
>   					VIRTIO_RXQ, p_cpl, MAX_PKT_BURST);
> -	if (complete_count) {
> +	if (complete_count)
>   		free_pkts(p_cpl, complete_count);
> -		__atomic_sub_fetch(&vdev->pkts_inflight, complete_count, __ATOMIC_SEQ_CST);
> -	}
> -
>   }
>   
>   static __rte_always_inline void
> @@ -886,7 +883,6 @@ drain_vhost(struct vhost_dev *vdev)
>   
>   		complete_async_pkts(vdev);
>   		ret = rte_vhost_submit_enqueue_burst(vdev->vid, VIRTIO_RXQ, m, nr_xmit);
> -		__atomic_add_fetch(&vdev->pkts_inflight, ret, __ATOMIC_SEQ_CST);
>   
>   		enqueue_fail = nr_xmit - ret;
>   		if (enqueue_fail)
> @@ -1212,7 +1208,6 @@ drain_eth_rx(struct vhost_dev *vdev)
>   		complete_async_pkts(vdev);
>   		enqueue_count = rte_vhost_submit_enqueue_burst(vdev->vid,
>   					VIRTIO_RXQ, pkts, rx_count);
> -		__atomic_add_fetch(&vdev->pkts_inflight, enqueue_count, __ATOMIC_SEQ_CST);
>   
>   		enqueue_fail = rx_count - enqueue_count;
>   		if (enqueue_fail)
> @@ -1338,6 +1333,7 @@ destroy_device(int vid)
>   	struct vhost_dev *vdev = NULL;
>   	int lcore;
>   	uint16_t i;

> +	int pkts_inflight;

You can move this down to the block it is used in

>   
>   	TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
>   		if (vdev->vid == vid)
> @@ -1384,13 +1380,13 @@ destroy_device(int vid)
>   
>   	if (async_vhost_driver) {
>   		uint16_t n_pkt = 0;
> -		struct rte_mbuf *m_cpl[vdev->pkts_inflight];
> +		pkts_inflight = rte_vhost_async_get_inflight_thread_unsafe(vid, VIRTIO_RXQ);
> +		struct rte_mbuf *m_cpl[pkts_inflight];
>   
> -		while (vdev->pkts_inflight) {
> +		while (pkts_inflight) {
>   			n_pkt = rte_vhost_clear_queue_thread_unsafe(vid, VIRTIO_RXQ,
> -						m_cpl, vdev->pkts_inflight);
> +						m_cpl, pkts_inflight);
>   			free_pkts(m_cpl, n_pkt);
> -			__atomic_sub_fetch(&vdev->pkts_inflight, n_pkt, __ATOMIC_SEQ_CST);

This is an infinite loop if there are pkts_inflight, need to recheck 
pkts_inflight in the loop.

>   		}
>   
>   		rte_vhost_async_channel_unregister(vid, VIRTIO_RXQ);
> @@ -1486,6 +1482,7 @@ static int
>   vring_state_changed(int vid, uint16_t queue_id, int enable)
>   {
>   	struct vhost_dev *vdev = NULL;
> +	int pkts_inflight;
>   
>   	TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
>   		if (vdev->vid == vid)
> @@ -1500,13 +1497,13 @@ vring_state_changed(int vid, uint16_t queue_id, int enable)
>   	if (async_vhost_driver) {
>   		if (!enable) {
>   			uint16_t n_pkt = 0;
> -			struct rte_mbuf *m_cpl[vdev->pkts_inflight];
> +			pkts_inflight = rte_vhost_async_get_inflight_thread_unsafe(vid, queue_id);
> +			struct rte_mbuf *m_cpl[pkts_inflight];
>   
> -			while (vdev->pkts_inflight) {
> +			while (pkts_inflight) {
>   				n_pkt = rte_vhost_clear_queue_thread_unsafe(vid, queue_id,
> -							m_cpl, vdev->pkts_inflight);
> +							m_cpl, pkts_inflight);
>   				free_pkts(m_cpl, n_pkt);
> -				__atomic_sub_fetch(&vdev->pkts_inflight, n_pkt, __ATOMIC_SEQ_CST);

Same comments as destroy_device

>   			}
>   		}
>   	}
> diff --git a/examples/vhost/main.h b/examples/vhost/main.h
> index e7b1ac60a6..0ccdce4b4a 100644
> --- a/examples/vhost/main.h
> +++ b/examples/vhost/main.h
> @@ -51,7 +51,6 @@ struct vhost_dev {
>   	uint64_t features;
>   	size_t hdr_len;
>   	uint16_t nr_vrings;
> -	uint16_t pkts_inflight;
>   	struct rte_vhost_memory *mem;
>   	struct device_statistics stats;
>   	TAILQ_ENTRY(vhost_dev) global_vdev_entry;
>
Ding, Xuan Sept. 28, 2021, 11:50 a.m. UTC | #2 
Hi Kevin,

> -----Original Message-----
> From: Kevin Traynor <ktraynor@redhat.com>
> Sent: Tuesday, September 28, 2021 5:18 PM
> To: Ding, Xuan <xuan.ding@intel.com>; dev@dpdk.org;
> maxime.coquelin@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>
> Cc: Hu, Jiayu <jiayu.hu@intel.com>; Jiang, Cheng1 <cheng1.jiang@intel.com>;
> Richardson, Bruce <bruce.richardson@intel.com>; Pai G, Sunil
> <sunil.pai.g@intel.com>; Wang, Yinan <yinan.wang@intel.com>; Yang, YvonneX
> <yvonnex.yang@intel.com>
> Subject: Re: [PATCH v5 2/2] examples/vhost: use API to check inflight packets
> 
> On 28/09/2021 07:24, Xuan Ding wrote:
> > In async data path, call rte_vhost_async_get_inflight_thread_unsafe()
> > API to directly return the number of inflight packets instead of
> > maintaining a local variable.
> >
> > Signed-off-by: Xuan Ding <xuan.ding@intel.com>
> > ---
> >   examples/vhost/main.c | 25 +++++++++++--------------
> >   examples/vhost/main.h |  1 -
> >   2 files changed, 11 insertions(+), 15 deletions(-)
> >
> > diff --git a/examples/vhost/main.c b/examples/vhost/main.c
> > index d0bf1f31e3..3faac6d053 100644
> > --- a/examples/vhost/main.c
> > +++ b/examples/vhost/main.c
> > @@ -842,11 +842,8 @@ complete_async_pkts(struct vhost_dev *vdev)
> >
> >   	complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
> >   					VIRTIO_RXQ, p_cpl, MAX_PKT_BURST);
> > -	if (complete_count) {
> > +	if (complete_count)
> >   		free_pkts(p_cpl, complete_count);
> > -		__atomic_sub_fetch(&vdev->pkts_inflight, complete_count,
> __ATOMIC_SEQ_CST);
> > -	}
> > -
> >   }
> >
> >   static __rte_always_inline void
> > @@ -886,7 +883,6 @@ drain_vhost(struct vhost_dev *vdev)
> >
> >   		complete_async_pkts(vdev);
> >   		ret = rte_vhost_submit_enqueue_burst(vdev->vid, VIRTIO_RXQ,
> m, nr_xmit);
> > -		__atomic_add_fetch(&vdev->pkts_inflight, ret,
> __ATOMIC_SEQ_CST);
> >
> >   		enqueue_fail = nr_xmit - ret;
> >   		if (enqueue_fail)
> > @@ -1212,7 +1208,6 @@ drain_eth_rx(struct vhost_dev *vdev)
> >   		complete_async_pkts(vdev);
> >   		enqueue_count = rte_vhost_submit_enqueue_burst(vdev->vid,
> >   					VIRTIO_RXQ, pkts, rx_count);
> > -		__atomic_add_fetch(&vdev->pkts_inflight, enqueue_count,
> __ATOMIC_SEQ_CST);
> >
> >   		enqueue_fail = rx_count - enqueue_count;
> >   		if (enqueue_fail)
> > @@ -1338,6 +1333,7 @@ destroy_device(int vid)
> >   	struct vhost_dev *vdev = NULL;
> >   	int lcore;
> >   	uint16_t i;
> 
> > +	int pkts_inflight;
> 
> You can move this down to the block it is used in

Thanks for the suggestion.
I consider calling the unsafe API in while (condition), and there is no need to define this variable.

> 
> >
> >   	TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
> >   		if (vdev->vid == vid)
> > @@ -1384,13 +1380,13 @@ destroy_device(int vid)
> >
> >   	if (async_vhost_driver) {
> >   		uint16_t n_pkt = 0;
> > -		struct rte_mbuf *m_cpl[vdev->pkts_inflight];
> > +		pkts_inflight = rte_vhost_async_get_inflight_thread_unsafe(vid,
> VIRTIO_RXQ);
> > +		struct rte_mbuf *m_cpl[pkts_inflight];
> >
> > -		while (vdev->pkts_inflight) {
> > +		while (pkts_inflight) {
> >   			n_pkt = rte_vhost_clear_queue_thread_unsafe(vid,
> VIRTIO_RXQ,
> > -						m_cpl, vdev->pkts_inflight);
> > +						m_cpl, pkts_inflight);
> >   			free_pkts(m_cpl, n_pkt);
> > -			__atomic_sub_fetch(&vdev->pkts_inflight, n_pkt,
> __ATOMIC_SEQ_CST);
> 
> This is an infinite loop if there are pkts_inflight, need to recheck
> pkts_inflight in the loop.

Thanks for the catch, will call the unsafe API directly in the while (condition).

> 
> >   		}
> >
> >   		rte_vhost_async_channel_unregister(vid, VIRTIO_RXQ);
> > @@ -1486,6 +1482,7 @@ static int
> >   vring_state_changed(int vid, uint16_t queue_id, int enable)
> >   {
> >   	struct vhost_dev *vdev = NULL;
> > +	int pkts_inflight;
> >
> >   	TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
> >   		if (vdev->vid == vid)
> > @@ -1500,13 +1497,13 @@ vring_state_changed(int vid, uint16_t queue_id,
> int enable)
> >   	if (async_vhost_driver) {
> >   		if (!enable) {
> >   			uint16_t n_pkt = 0;
> > -			struct rte_mbuf *m_cpl[vdev->pkts_inflight];
> > +			pkts_inflight =
> rte_vhost_async_get_inflight_thread_unsafe(vid, queue_id);
> > +			struct rte_mbuf *m_cpl[pkts_inflight];
> >
> > -			while (vdev->pkts_inflight) {
> > +			while (pkts_inflight) {
> >   				n_pkt =
> rte_vhost_clear_queue_thread_unsafe(vid, queue_id,
> > -							m_cpl, vdev-
> >pkts_inflight);
> > +							m_cpl, pkts_inflight);
> >   				free_pkts(m_cpl, n_pkt);
> > -				__atomic_sub_fetch(&vdev->pkts_inflight,
> n_pkt, __ATOMIC_SEQ_CST);
> 
> Same comments as destroy_device

Same as vring_state_changed.

Regards,
Xuan

> 
> >   			}
> >   		}
> >   	}
> > diff --git a/examples/vhost/main.h b/examples/vhost/main.h
> > index e7b1ac60a6..0ccdce4b4a 100644
> > --- a/examples/vhost/main.h
> > +++ b/examples/vhost/main.h
> > @@ -51,7 +51,6 @@ struct vhost_dev {
> >   	uint64_t features;
> >   	size_t hdr_len;
> >   	uint16_t nr_vrings;
> > -	uint16_t pkts_inflight;
> >   	struct rte_vhost_memory *mem;
> >   	struct device_statistics stats;
> >   	TAILQ_ENTRY(vhost_dev) global_vdev_entry;
> >
Ding, Xuan Sept. 28, 2021, 11:59 a.m. UTC | #3 
Hi,

> -----Original Message-----
> From: Ding, Xuan
> Sent: Tuesday, September 28, 2021 7:51 PM
> To: Kevin Traynor <ktraynor@redhat.com>; dev@dpdk.org;
> maxime.coquelin@redhat.com; Xia, Chenbo <Chenbo.Xia@intel.com>
> Cc: Hu, Jiayu <Jiayu.Hu@intel.com>; Jiang, Cheng1 <Cheng1.Jiang@intel.com>;
> Richardson, Bruce <bruce.richardson@intel.com>; Pai G, Sunil
> <Sunil.Pai.G@intel.com>; Wang, Yinan <yinan.wang@intel.com>; Yang,
> YvonneX <YvonneX.Yang@intel.com>
> Subject: RE: [PATCH v5 2/2] examples/vhost: use API to check inflight packets
> 
> Hi Kevin,
> 
> > -----Original Message-----
> > From: Kevin Traynor <ktraynor@redhat.com>
> > Sent: Tuesday, September 28, 2021 5:18 PM
> > To: Ding, Xuan <xuan.ding@intel.com>; dev@dpdk.org;
> > maxime.coquelin@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>
> > Cc: Hu, Jiayu <jiayu.hu@intel.com>; Jiang, Cheng1 <cheng1.jiang@intel.com>;
> > Richardson, Bruce <bruce.richardson@intel.com>; Pai G, Sunil
> > <sunil.pai.g@intel.com>; Wang, Yinan <yinan.wang@intel.com>; Yang,
> YvonneX
> > <yvonnex.yang@intel.com>
> > Subject: Re: [PATCH v5 2/2] examples/vhost: use API to check inflight packets
> >
> > On 28/09/2021 07:24, Xuan Ding wrote:
> > > In async data path, call rte_vhost_async_get_inflight_thread_unsafe()
> > > API to directly return the number of inflight packets instead of
> > > maintaining a local variable.
> > >
> > > Signed-off-by: Xuan Ding <xuan.ding@intel.com>
> > > ---
> > >   examples/vhost/main.c | 25 +++++++++++--------------
> > >   examples/vhost/main.h |  1 -
> > >   2 files changed, 11 insertions(+), 15 deletions(-)
> > >
> > > diff --git a/examples/vhost/main.c b/examples/vhost/main.c
> > > index d0bf1f31e3..3faac6d053 100644
> > > --- a/examples/vhost/main.c
> > > +++ b/examples/vhost/main.c
> > > @@ -842,11 +842,8 @@ complete_async_pkts(struct vhost_dev *vdev)
> > >
> > >   	complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
> > >   					VIRTIO_RXQ, p_cpl, MAX_PKT_BURST);
> > > -	if (complete_count) {
> > > +	if (complete_count)
> > >   		free_pkts(p_cpl, complete_count);
> > > -		__atomic_sub_fetch(&vdev->pkts_inflight, complete_count,
> > __ATOMIC_SEQ_CST);
> > > -	}
> > > -
> > >   }
> > >
> > >   static __rte_always_inline void
> > > @@ -886,7 +883,6 @@ drain_vhost(struct vhost_dev *vdev)
> > >
> > >   		complete_async_pkts(vdev);
> > >   		ret = rte_vhost_submit_enqueue_burst(vdev->vid, VIRTIO_RXQ,
> > m, nr_xmit);
> > > -		__atomic_add_fetch(&vdev->pkts_inflight, ret,
> > __ATOMIC_SEQ_CST);
> > >
> > >   		enqueue_fail = nr_xmit - ret;
> > >   		if (enqueue_fail)
> > > @@ -1212,7 +1208,6 @@ drain_eth_rx(struct vhost_dev *vdev)
> > >   		complete_async_pkts(vdev);
> > >   		enqueue_count = rte_vhost_submit_enqueue_burst(vdev->vid,
> > >   					VIRTIO_RXQ, pkts, rx_count);
> > > -		__atomic_add_fetch(&vdev->pkts_inflight, enqueue_count,
> > __ATOMIC_SEQ_CST);
> > >
> > >   		enqueue_fail = rx_count - enqueue_count;
> > >   		if (enqueue_fail)
> > > @@ -1338,6 +1333,7 @@ destroy_device(int vid)
> > >   	struct vhost_dev *vdev = NULL;
> > >   	int lcore;
> > >   	uint16_t i;
> >
> > > +	int pkts_inflight;
> >
> > You can move this down to the block it is used in
> 
> Thanks for the suggestion.
> I consider calling the unsafe API in while (condition), and there is no need to
> define this variable.
> 
> >
> > >
> > >   	TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
> > >   		if (vdev->vid == vid)
> > > @@ -1384,13 +1380,13 @@ destroy_device(int vid)
> > >
> > >   	if (async_vhost_driver) {
> > >   		uint16_t n_pkt = 0;
> > > -		struct rte_mbuf *m_cpl[vdev->pkts_inflight];
> > > +		pkts_inflight = rte_vhost_async_get_inflight_thread_unsafe(vid,
> > VIRTIO_RXQ);
> > > +		struct rte_mbuf *m_cpl[pkts_inflight];
> > >
> > > -		while (vdev->pkts_inflight) {
> > > +		while (pkts_inflight) {
> > >   			n_pkt = rte_vhost_clear_queue_thread_unsafe(vid,
> > VIRTIO_RXQ,
> > > -						m_cpl, vdev->pkts_inflight);
> > > +						m_cpl, pkts_inflight);
> > >   			free_pkts(m_cpl, n_pkt);
> > > -			__atomic_sub_fetch(&vdev->pkts_inflight, n_pkt,
> > __ATOMIC_SEQ_CST);
> >
> > This is an infinite loop if there are pkts_inflight, need to recheck
> > pkts_inflight in the loop.
> 
> Thanks for the catch, will call the unsafe API directly in the while (condition).

Sorry for replying myself, as rte_mbuf *m_cpl also needs pkts_inflight here.
Will follow your suggestion, see next version, thanks!

Regards,
Xuan

> 
> >
> > >   		}
> > >
> > >   		rte_vhost_async_channel_unregister(vid, VIRTIO_RXQ);
> > > @@ -1486,6 +1482,7 @@ static int
> > >   vring_state_changed(int vid, uint16_t queue_id, int enable)
> > >   {
> > >   	struct vhost_dev *vdev = NULL;
> > > +	int pkts_inflight;
> > >
> > >   	TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
> > >   		if (vdev->vid == vid)
> > > @@ -1500,13 +1497,13 @@ vring_state_changed(int vid, uint16_t queue_id,
> > int enable)
> > >   	if (async_vhost_driver) {
> > >   		if (!enable) {
> > >   			uint16_t n_pkt = 0;
> > > -			struct rte_mbuf *m_cpl[vdev->pkts_inflight];
> > > +			pkts_inflight =
> > rte_vhost_async_get_inflight_thread_unsafe(vid, queue_id);
> > > +			struct rte_mbuf *m_cpl[pkts_inflight];
> > >
> > > -			while (vdev->pkts_inflight) {
> > > +			while (pkts_inflight) {
> > >   				n_pkt =
> > rte_vhost_clear_queue_thread_unsafe(vid, queue_id,
> > > -							m_cpl, vdev-
> > >pkts_inflight);
> > > +							m_cpl, pkts_inflight);
> > >   				free_pkts(m_cpl, n_pkt);
> > > -				__atomic_sub_fetch(&vdev->pkts_inflight,
> > n_pkt, __ATOMIC_SEQ_CST);
> >
> > Same comments as destroy_device
> 
> Same as vring_state_changed.
> 
> Regards,
> Xuan
> 
> >
> > >   			}
> > >   		}
> > >   	}
> > > diff --git a/examples/vhost/main.h b/examples/vhost/main.h
> > > index e7b1ac60a6..0ccdce4b4a 100644
> > > --- a/examples/vhost/main.h
> > > +++ b/examples/vhost/main.h
> > > @@ -51,7 +51,6 @@ struct vhost_dev {
> > >   	uint64_t features;
> > >   	size_t hdr_len;
> > >   	uint16_t nr_vrings;
> > > -	uint16_t pkts_inflight;
> > >   	struct rte_vhost_memory *mem;
> > >   	struct device_statistics stats;
> > >   	TAILQ_ENTRY(vhost_dev) global_vdev_entry;
> > >
diff mbox series

Patch

diff --git a/examples/vhost/main.c b/examples/vhost/main.c
index d0bf1f31e3..3faac6d053 100644
--- a/examples/vhost/main.c
+++ b/examples/vhost/main.c
@@ -842,11 +842,8 @@  complete_async_pkts(struct vhost_dev *vdev)
 
 	complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
 					VIRTIO_RXQ, p_cpl, MAX_PKT_BURST);
-	if (complete_count) {
+	if (complete_count)
 		free_pkts(p_cpl, complete_count);
-		__atomic_sub_fetch(&vdev->pkts_inflight, complete_count, __ATOMIC_SEQ_CST);
-	}
-
 }
 
 static __rte_always_inline void
@@ -886,7 +883,6 @@  drain_vhost(struct vhost_dev *vdev)
 
 		complete_async_pkts(vdev);
 		ret = rte_vhost_submit_enqueue_burst(vdev->vid, VIRTIO_RXQ, m, nr_xmit);
-		__atomic_add_fetch(&vdev->pkts_inflight, ret, __ATOMIC_SEQ_CST);
 
 		enqueue_fail = nr_xmit - ret;
 		if (enqueue_fail)
@@ -1212,7 +1208,6 @@  drain_eth_rx(struct vhost_dev *vdev)
 		complete_async_pkts(vdev);
 		enqueue_count = rte_vhost_submit_enqueue_burst(vdev->vid,
 					VIRTIO_RXQ, pkts, rx_count);
-		__atomic_add_fetch(&vdev->pkts_inflight, enqueue_count, __ATOMIC_SEQ_CST);
 
 		enqueue_fail = rx_count - enqueue_count;
 		if (enqueue_fail)
@@ -1338,6 +1333,7 @@  destroy_device(int vid)
 	struct vhost_dev *vdev = NULL;
 	int lcore;
 	uint16_t i;
+	int pkts_inflight;
 
 	TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
 		if (vdev->vid == vid)
@@ -1384,13 +1380,13 @@  destroy_device(int vid)
 
 	if (async_vhost_driver) {
 		uint16_t n_pkt = 0;
-		struct rte_mbuf *m_cpl[vdev->pkts_inflight];
+		pkts_inflight = rte_vhost_async_get_inflight_thread_unsafe(vid, VIRTIO_RXQ);
+		struct rte_mbuf *m_cpl[pkts_inflight];
 
-		while (vdev->pkts_inflight) {
+		while (pkts_inflight) {
 			n_pkt = rte_vhost_clear_queue_thread_unsafe(vid, VIRTIO_RXQ,
-						m_cpl, vdev->pkts_inflight);
+						m_cpl, pkts_inflight);
 			free_pkts(m_cpl, n_pkt);
-			__atomic_sub_fetch(&vdev->pkts_inflight, n_pkt, __ATOMIC_SEQ_CST);
 		}
 
 		rte_vhost_async_channel_unregister(vid, VIRTIO_RXQ);
@@ -1486,6 +1482,7 @@  static int
 vring_state_changed(int vid, uint16_t queue_id, int enable)
 {
 	struct vhost_dev *vdev = NULL;
+	int pkts_inflight;
 
 	TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
 		if (vdev->vid == vid)
@@ -1500,13 +1497,13 @@  vring_state_changed(int vid, uint16_t queue_id, int enable)
 	if (async_vhost_driver) {
 		if (!enable) {
 			uint16_t n_pkt = 0;
-			struct rte_mbuf *m_cpl[vdev->pkts_inflight];
+			pkts_inflight = rte_vhost_async_get_inflight_thread_unsafe(vid, queue_id);
+			struct rte_mbuf *m_cpl[pkts_inflight];
 
-			while (vdev->pkts_inflight) {
+			while (pkts_inflight) {
 				n_pkt = rte_vhost_clear_queue_thread_unsafe(vid, queue_id,
-							m_cpl, vdev->pkts_inflight);
+							m_cpl, pkts_inflight);
 				free_pkts(m_cpl, n_pkt);
-				__atomic_sub_fetch(&vdev->pkts_inflight, n_pkt, __ATOMIC_SEQ_CST);
 			}
 		}
 	}
diff --git a/examples/vhost/main.h b/examples/vhost/main.h
index e7b1ac60a6..0ccdce4b4a 100644
--- a/examples/vhost/main.h
+++ b/examples/vhost/main.h
@@ -51,7 +51,6 @@  struct vhost_dev {
 	uint64_t features;
 	size_t hdr_len;
 	uint16_t nr_vrings;
-	uint16_t pkts_inflight;
 	struct rte_vhost_memory *mem;
 	struct device_statistics stats;
 	TAILQ_ENTRY(vhost_dev) global_vdev_entry;