diff mbox series

[v2] vhost: support async copy free segmentations

Message ID 20200715111520.2755307-1-patrick.fu@intel.com (mailing list archive)
State Changes Requested, archived
Delegated to: Maxime Coquelin
Headers
Series [v2] vhost: support async copy free segmentations |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK
ci/travis-robot success Travis build: passed
ci/iol-intel-Performance success Performance Testing PASS
ci/iol-testing success Testing PASS
ci/iol-broadcom-Performance success Performance Testing PASS

Commit Message

Patrick Fu July 15, 2020, 11:15 a.m. UTC 
  From: Patrick Fu <patrick.fu@intel.com>

Vhost async enqueue assumes that all async copies should break at packet
boundary. i.e. if a packet is splited into multiple copy segments, the
async engine should always report copy completion when entire packet is
finished. This patch removes the assumption.

Fixes: cd6760da1076 ("vhost: introduce async enqueue for split ring")

Signed-off-by: Patrick Fu <patrick.fu@intel.com>
---
v2:
 - fix an issue that can stuck async poll when packets buffer is full
 - rename a local variable to better reflect its usage

 lib/librte_vhost/vhost.h      |  3 +++
 lib/librte_vhost/virtio_net.c | 17 ++++++++++++-----
 2 files changed, 15 insertions(+), 5 deletions(-)

Comments

Chenbo Xia July 17, 2020, 3:21 a.m. UTC | #1 
> -----Original Message-----
> From: Fu, Patrick <patrick.fu@intel.com>
> Sent: Wednesday, July 15, 2020 7:15 PM
> To: dev@dpdk.org; maxime.coquelin@redhat.com; Xia, Chenbo
> <chenbo.xia@intel.com>
> Cc: Fu, Patrick <patrick.fu@intel.com>; Wang, Yinan <yinan.wang@intel.com>
> Subject: [PATCH v2] vhost: support async copy free segmentations
> 
> From: Patrick Fu <patrick.fu@intel.com>
> 
> Vhost async enqueue assumes that all async copies should break at packet
> boundary. i.e. if a packet is splited into multiple copy segments, the async engine
> should always report copy completion when entire packet is finished. This patch
> removes the assumption.
> 
> Fixes: cd6760da1076 ("vhost: introduce async enqueue for split ring")
> 
> Signed-off-by: Patrick Fu <patrick.fu@intel.com>
> ---
> v2:
>  - fix an issue that can stuck async poll when packets buffer is full
>  - rename a local variable to better reflect its usage
> 
>  lib/librte_vhost/vhost.h      |  3 +++
>  lib/librte_vhost/virtio_net.c | 17 ++++++++++++-----
>  2 files changed, 15 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h index
> 8c01cee42..0f7212f88 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -46,6 +46,8 @@
> 
>  #define MAX_PKT_BURST 32
> 
> +#define ASYNC_MAX_POLL_SEG 255
> +
>  #define VHOST_MAX_ASYNC_IT (MAX_PKT_BURST * 2)  #define
> VHOST_MAX_ASYNC_VEC (BUF_VECTOR_MAX * 2)
> 
> @@ -225,6 +227,7 @@ struct vhost_virtqueue {
>  	uint64_t	*async_pending_info;
>  	uint16_t	async_pkts_idx;
>  	uint16_t	async_pkts_inflight_n;
> +	uint16_t	async_last_seg_n;
> 
>  	/* vq async features */
>  	bool		async_inorder;
> diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c index
> 1d0be3dd4..17808ab29 100644
> --- a/lib/librte_vhost/virtio_net.c
> +++ b/lib/librte_vhost/virtio_net.c
> @@ -1633,6 +1633,7 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid,
> uint16_t queue_id,
>  	struct vhost_virtqueue *vq;
>  	uint16_t n_pkts_cpl, n_pkts_put = 0, n_descs = 0;
>  	uint16_t start_idx, pkts_idx, vq_size;
> +	uint16_t n_inflight;
>  	uint64_t *async_pending_info;
> 
>  	VHOST_LOG_DATA(DEBUG, "(%d) %s\n", dev->vid, __func__); @@ -
> 1646,28 +1647,32 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid,
> uint16_t queue_id,
> 
>  	rte_spinlock_lock(&vq->access_lock);
> 
> +	n_inflight = vq->async_pkts_inflight_n;
>  	pkts_idx = vq->async_pkts_idx;
>  	async_pending_info = vq->async_pending_info;
>  	vq_size = vq->size;
>  	start_idx = virtio_dev_rx_async_get_info_idx(pkts_idx,
>  		vq_size, vq->async_pkts_inflight_n);
> 
> -	n_pkts_cpl =
> -		vq->async_ops.check_completed_copies(vid, queue_id, 0,
> count);
> +	n_pkts_cpl = vq->async_ops.check_completed_copies(vid, queue_id,
> +		0, ASYNC_MAX_POLL_SEG - vq->async_last_seg_n) +
> +		vq->async_last_seg_n;
> 
>  	rte_smp_wmb();
> 
> -	while (likely(((start_idx + n_pkts_put) & (vq_size - 1)) != pkts_idx)) {
> +	while (likely((n_pkts_put < count) && n_inflight)) {
>  		uint64_t info = async_pending_info[
>  			(start_idx + n_pkts_put) & (vq_size - 1)];
>  		uint64_t n_segs;
>  		n_pkts_put++;
> +		n_inflight--;
>  		n_descs += info & ASYNC_PENDING_INFO_N_MSK;
>  		n_segs = info >> ASYNC_PENDING_INFO_N_SFT;
> 
>  		if (n_segs) {
> -			if (!n_pkts_cpl || n_pkts_cpl < n_segs) {
> +			if (unlikely(n_pkts_cpl < n_segs)) {
>  				n_pkts_put--;
> +				n_inflight++;
>  				n_descs -= info &
> ASYNC_PENDING_INFO_N_MSK;
>  				if (n_pkts_cpl) {
>  					async_pending_info[
> @@ -1684,8 +1689,10 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid,
> uint16_t queue_id,
>  		}
>  	}
> 
> +	vq->async_last_seg_n = n_pkts_cpl;
> +
>  	if (n_pkts_put) {
> -		vq->async_pkts_inflight_n -= n_pkts_put;
> +		vq->async_pkts_inflight_n = n_inflight;
>  		__atomic_add_fetch(&vq->used->idx, n_descs,
> __ATOMIC_RELEASE);
> 
>  		vhost_vring_call_split(dev, vq);
> --
> 2.18.4

Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
Ferruh Yigit July 17, 2020, 11:52 a.m. UTC | #2 
On 7/17/2020 4:21 AM, Xia, Chenbo wrote:
> 
>> -----Original Message-----
>> From: Fu, Patrick <patrick.fu@intel.com>
>> Sent: Wednesday, July 15, 2020 7:15 PM
>> To: dev@dpdk.org; maxime.coquelin@redhat.com; Xia, Chenbo
>> <chenbo.xia@intel.com>
>> Cc: Fu, Patrick <patrick.fu@intel.com>; Wang, Yinan <yinan.wang@intel.com>
>> Subject: [PATCH v2] vhost: support async copy free segmentations
>>
>> From: Patrick Fu <patrick.fu@intel.com>
>>
>> Vhost async enqueue assumes that all async copies should break at packet
>> boundary. i.e. if a packet is splited into multiple copy segments, the async engine
>> should always report copy completion when entire packet is finished. This patch
>> removes the assumption.
>>
>> Fixes: cd6760da1076 ("vhost: introduce async enqueue for split ring")
>>
>> Signed-off-by: Patrick Fu <patrick.fu@intel.com>
> 
> Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
> 

Applied to dpdk-next-net/master, thanks.
Maxime Coquelin July 20, 2020, 2:58 p.m. UTC | #3 
Hi Patrick,

On 7/15/20 1:15 PM, patrick.fu@intel.com wrote:
> From: Patrick Fu <patrick.fu@intel.com>
> 
> Vhost async enqueue assumes that all async copies should break at packet
> boundary. i.e. if a packet is splited into multiple copy segments, the
> async engine should always report copy completion when entire packet is
> finished. This patch removes the assumption.

Could you please rework the commit message and title?
It is hard to understand what the patch is doing and why.

Thanks in advance,
Maxime

> Fixes: cd6760da1076 ("vhost: introduce async enqueue for split ring")
> 
> Signed-off-by: Patrick Fu <patrick.fu@intel.com>
> ---
> v2:
>  - fix an issue that can stuck async poll when packets buffer is full
>  - rename a local variable to better reflect its usage
> 
>  lib/librte_vhost/vhost.h      |  3 +++
>  lib/librte_vhost/virtio_net.c | 17 ++++++++++++-----
>  2 files changed, 15 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
> index 8c01cee42..0f7212f88 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -46,6 +46,8 @@
>  
>  #define MAX_PKT_BURST 32
>  
> +#define ASYNC_MAX_POLL_SEG 255
> +
>  #define VHOST_MAX_ASYNC_IT (MAX_PKT_BURST * 2)
>  #define VHOST_MAX_ASYNC_VEC (BUF_VECTOR_MAX * 2)
>  
> @@ -225,6 +227,7 @@ struct vhost_virtqueue {
>  	uint64_t	*async_pending_info;
>  	uint16_t	async_pkts_idx;
>  	uint16_t	async_pkts_inflight_n;
> +	uint16_t	async_last_seg_n;
>  
>  	/* vq async features */
>  	bool		async_inorder;
> diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
> index 1d0be3dd4..17808ab29 100644
> --- a/lib/librte_vhost/virtio_net.c
> +++ b/lib/librte_vhost/virtio_net.c
> @@ -1633,6 +1633,7 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
>  	struct vhost_virtqueue *vq;
>  	uint16_t n_pkts_cpl, n_pkts_put = 0, n_descs = 0;
>  	uint16_t start_idx, pkts_idx, vq_size;
> +	uint16_t n_inflight;
>  	uint64_t *async_pending_info;
>  
>  	VHOST_LOG_DATA(DEBUG, "(%d) %s\n", dev->vid, __func__);
> @@ -1646,28 +1647,32 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
>  
>  	rte_spinlock_lock(&vq->access_lock);
>  
> +	n_inflight = vq->async_pkts_inflight_n;
>  	pkts_idx = vq->async_pkts_idx;
>  	async_pending_info = vq->async_pending_info;
>  	vq_size = vq->size;
>  	start_idx = virtio_dev_rx_async_get_info_idx(pkts_idx,
>  		vq_size, vq->async_pkts_inflight_n);
>  
> -	n_pkts_cpl =
> -		vq->async_ops.check_completed_copies(vid, queue_id, 0, count);
> +	n_pkts_cpl = vq->async_ops.check_completed_copies(vid, queue_id,
> +		0, ASYNC_MAX_POLL_SEG - vq->async_last_seg_n) +
> +		vq->async_last_seg_n;
>  
>  	rte_smp_wmb();
>  
> -	while (likely(((start_idx + n_pkts_put) & (vq_size - 1)) != pkts_idx)) {
> +	while (likely((n_pkts_put < count) && n_inflight)) {
>  		uint64_t info = async_pending_info[
>  			(start_idx + n_pkts_put) & (vq_size - 1)];
>  		uint64_t n_segs;
>  		n_pkts_put++;
> +		n_inflight--;
>  		n_descs += info & ASYNC_PENDING_INFO_N_MSK;
>  		n_segs = info >> ASYNC_PENDING_INFO_N_SFT;
>  
>  		if (n_segs) {
> -			if (!n_pkts_cpl || n_pkts_cpl < n_segs) {
> +			if (unlikely(n_pkts_cpl < n_segs)) {
>  				n_pkts_put--;
> +				n_inflight++;
>  				n_descs -= info & ASYNC_PENDING_INFO_N_MSK;
>  				if (n_pkts_cpl) {
>  					async_pending_info[
> @@ -1684,8 +1689,10 @@ uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
>  		}
>  	}
>  
> +	vq->async_last_seg_n = n_pkts_cpl;
> +
>  	if (n_pkts_put) {
> -		vq->async_pkts_inflight_n -= n_pkts_put;
> +		vq->async_pkts_inflight_n = n_inflight;
>  		__atomic_add_fetch(&vq->used->idx, n_descs, __ATOMIC_RELEASE);
>  
>  		vhost_vring_call_split(dev, vq);
>
Ferruh Yigit July 20, 2020, 4:49 p.m. UTC | #4 
On 7/20/2020 3:58 PM, Maxime Coquelin wrote:
> Hi Patrick,
> 
> On 7/15/20 1:15 PM, patrick.fu@intel.com wrote:
>> From: Patrick Fu <patrick.fu@intel.com>
>>
>> Vhost async enqueue assumes that all async copies should break at packet
>> boundary. i.e. if a packet is splited into multiple copy segments, the
>> async engine should always report copy completion when entire packet is
>> finished. This patch removes the assumption.
> 
> Could you please rework the commit message and title?
> It is hard to understand what the patch is doing and why.

Existing commit dropped from next-net and patchwork status updated.

> 
> Thanks in advance,
> Maxime
> 
>> Fixes: cd6760da1076 ("vhost: introduce async enqueue for split ring")
>>
>> Signed-off-by: Patrick Fu <patrick.fu@intel.com>

<...>
Patrick Fu July 21, 2020, 5:52 a.m. UTC | #5 
Hi Maxime,

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Monday, July 20, 2020 10:58 PM
> To: Fu, Patrick <patrick.fu@intel.com>; dev@dpdk.org; Xia, Chenbo
> <chenbo.xia@intel.com>
> Cc: Wang, Yinan <yinan.wang@intel.com>
> Subject: Re: [PATCH v2] vhost: support async copy free segmentations
> 
> Hi Patrick,
> 
> On 7/15/20 1:15 PM, patrick.fu@intel.com wrote:
> > From: Patrick Fu <patrick.fu@intel.com>
> >
> > Vhost async enqueue assumes that all async copies should break at
> > packet boundary. i.e. if a packet is splited into multiple copy
> > segments, the async engine should always report copy completion when
> > entire packet is finished. This patch removes the assumption.
> 
> Could you please rework the commit message and title?
> It is hard to understand what the patch is doing and why.

I  revise the commit message and title in my v3 patch. Hope that one will be more clear.

Thanks,

Patrick
diff mbox series

Patch

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 8c01cee42..0f7212f88 100644
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -46,6 +46,8 @@ 
 
 #define MAX_PKT_BURST 32
 
+#define ASYNC_MAX_POLL_SEG 255
+
 #define VHOST_MAX_ASYNC_IT (MAX_PKT_BURST * 2)
 #define VHOST_MAX_ASYNC_VEC (BUF_VECTOR_MAX * 2)
 
@@ -225,6 +227,7 @@  struct vhost_virtqueue {
 	uint64_t	*async_pending_info;
 	uint16_t	async_pkts_idx;
 	uint16_t	async_pkts_inflight_n;
+	uint16_t	async_last_seg_n;
 
 	/* vq async features */
 	bool		async_inorder;
diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 1d0be3dd4..17808ab29 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -1633,6 +1633,7 @@  uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
 	struct vhost_virtqueue *vq;
 	uint16_t n_pkts_cpl, n_pkts_put = 0, n_descs = 0;
 	uint16_t start_idx, pkts_idx, vq_size;
+	uint16_t n_inflight;
 	uint64_t *async_pending_info;
 
 	VHOST_LOG_DATA(DEBUG, "(%d) %s\n", dev->vid, __func__);
@@ -1646,28 +1647,32 @@  uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
 
 	rte_spinlock_lock(&vq->access_lock);
 
+	n_inflight = vq->async_pkts_inflight_n;
 	pkts_idx = vq->async_pkts_idx;
 	async_pending_info = vq->async_pending_info;
 	vq_size = vq->size;
 	start_idx = virtio_dev_rx_async_get_info_idx(pkts_idx,
 		vq_size, vq->async_pkts_inflight_n);
 
-	n_pkts_cpl =
-		vq->async_ops.check_completed_copies(vid, queue_id, 0, count);
+	n_pkts_cpl = vq->async_ops.check_completed_copies(vid, queue_id,
+		0, ASYNC_MAX_POLL_SEG - vq->async_last_seg_n) +
+		vq->async_last_seg_n;
 
 	rte_smp_wmb();
 
-	while (likely(((start_idx + n_pkts_put) & (vq_size - 1)) != pkts_idx)) {
+	while (likely((n_pkts_put < count) && n_inflight)) {
 		uint64_t info = async_pending_info[
 			(start_idx + n_pkts_put) & (vq_size - 1)];
 		uint64_t n_segs;
 		n_pkts_put++;
+		n_inflight--;
 		n_descs += info & ASYNC_PENDING_INFO_N_MSK;
 		n_segs = info >> ASYNC_PENDING_INFO_N_SFT;
 
 		if (n_segs) {
-			if (!n_pkts_cpl || n_pkts_cpl < n_segs) {
+			if (unlikely(n_pkts_cpl < n_segs)) {
 				n_pkts_put--;
+				n_inflight++;
 				n_descs -= info & ASYNC_PENDING_INFO_N_MSK;
 				if (n_pkts_cpl) {
 					async_pending_info[
@@ -1684,8 +1689,10 @@  uint16_t rte_vhost_poll_enqueue_completed(int vid, uint16_t queue_id,
 		}
 	}
 
+	vq->async_last_seg_n = n_pkts_cpl;
+
 	if (n_pkts_put) {
-		vq->async_pkts_inflight_n -= n_pkts_put;
+		vq->async_pkts_inflight_n = n_inflight;
 		__atomic_add_fetch(&vq->used->idx, n_descs, __ATOMIC_RELEASE);
 
 		vhost_vring_call_split(dev, vq);