diff mbox series

[v7,4/7] vhost: fix NUMA reallocation with multiqueue

Message ID 20210629161133.79472-5-maxime.coquelin@redhat.com (mailing list archive)
State Accepted, archived
Delegated to: Maxime Coquelin
Headers show
Series vhost: Fix and improve NUMA reallocation | expand

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Maxime Coquelin June 29, 2021, 4:11 p.m. UTC
Since the Vhost-user device initialization has been reworked,
enabling the application to start using the device as soon as
the first queue pair is ready, NUMA reallocation no more
happened on queue pairs other than the first one since
numa_realloc() was returning early if the device was running.

This patch fixes this issue by only preventing the device
metadata to be allocated if the device is running. For the
virtqueues, a vring state change notification is sent to
notify the application of its disablement. Since the callback
is supposed to be blocking, it is safe to reallocate it
afterwards.

Fixes: d0fcc38f5fa4 ("vhost: improve device readiness notifications")
Cc: stable@dpdk.org

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/vhost/vhost_user.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

Comments

Chenbo Xia June 30, 2021, 5:20 a.m. UTC | #1
> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Wednesday, June 30, 2021 12:12 AM
> To: dev@dpdk.org; Xia, Chenbo <chenbo.xia@intel.com>;
> david.marchand@redhat.com
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>; stable@dpdk.org
> Subject: [PATCH v7 4/7] vhost: fix NUMA reallocation with multiqueue
> 
> Since the Vhost-user device initialization has been reworked,
> enabling the application to start using the device as soon as
> the first queue pair is ready, NUMA reallocation no more
> happened on queue pairs other than the first one since
> numa_realloc() was returning early if the device was running.
> 
> This patch fixes this issue by only preventing the device
> metadata to be allocated if the device is running. For the
> virtqueues, a vring state change notification is sent to
> notify the application of its disablement. Since the callback
> is supposed to be blocking, it is safe to reallocate it
> afterwards.
> 
> Fixes: d0fcc38f5fa4 ("vhost: improve device readiness notifications")
> Cc: stable@dpdk.org
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  lib/vhost/vhost_user.c | 13 ++++++++++---
>  1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
> index 82adf80fe5..51b96a0716 100644
> --- a/lib/vhost/vhost_user.c
> +++ b/lib/vhost/vhost_user.c
> @@ -488,12 +488,16 @@ numa_realloc(struct virtio_net *dev, int index)
>  	struct batch_copy_elem *new_batch_copy_elems;
>  	int ret;
> 
> -	if (dev->flags & VIRTIO_DEV_RUNNING)
> -		return dev;
> -
>  	old_dev = dev;
>  	vq = old_vq = dev->virtqueue[index];
> 
> +	/*
> +	 * If VQ is ready, it is too late to reallocate, it certainly already
> +	 * happened anyway on VHOST_USER_SET_VRING_ADRR.
> +	 */
> +	if (vq->ready)
> +		return dev;
> +
>  	ret = get_mempolicy(&newnode, NULL, 0, old_vq->desc,
>  			    MPOL_F_NODE | MPOL_F_ADDR);
> 
> @@ -558,6 +562,9 @@ numa_realloc(struct virtio_net *dev, int index)
>  		rte_free(old_vq);
>  	}
> 
> +	if (dev->flags & VIRTIO_DEV_RUNNING)
> +		goto out;
> +
>  	/* check if we need to reallocate dev */
>  	ret = get_mempolicy(&oldnode, NULL, 0, old_dev,
>  			    MPOL_F_NODE | MPOL_F_ADDR);
> --
> 2.31.1

Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
David Marchand June 30, 2021, 7:24 a.m. UTC | #2
On Tue, Jun 29, 2021 at 6:11 PM Maxime Coquelin
<maxime.coquelin@redhat.com> wrote:
>
> Since the Vhost-user device initialization has been reworked,
> enabling the application to start using the device as soon as
> the first queue pair is ready, NUMA reallocation no more
> happened on queue pairs other than the first one since
> numa_realloc() was returning early if the device was running.
>
> This patch fixes this issue by only preventing the device
> metadata to be allocated if the device is running. For the

Hum, I understand the meaning, but I think we could make it easier to read:

This patch fixes this issue by reallocating the device metadata only
if the device is not running.

WDYT?

> virtqueues, a vring state change notification is sent to
> notify the application of its disablement. Since the callback
> is supposed to be blocking, it is safe to reallocate it
> afterwards.
Maxime Coquelin June 30, 2021, 7:47 a.m. UTC | #3
On 6/30/21 9:24 AM, David Marchand wrote:
> On Tue, Jun 29, 2021 at 6:11 PM Maxime Coquelin
> <maxime.coquelin@redhat.com> wrote:
>>
>> Since the Vhost-user device initialization has been reworked,
>> enabling the application to start using the device as soon as
>> the first queue pair is ready, NUMA reallocation no more
>> happened on queue pairs other than the first one since
>> numa_realloc() was returning early if the device was running.
>>
>> This patch fixes this issue by only preventing the device
>> metadata to be allocated if the device is running. For the
> 
> Hum, I understand the meaning, but I think we could make it easier to read:
> 
> This patch fixes this issue by reallocating the device metadata only
> if the device is not running.
> 
> WDYT?

It sounds better, I can be changed while applying if only issue.

>> virtqueues, a vring state change notification is sent to
>> notify the application of its disablement. Since the callback
>> is supposed to be blocking, it is safe to reallocate it
>> afterwards.
> 
>
diff mbox series

Patch

diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 82adf80fe5..51b96a0716 100644
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -488,12 +488,16 @@  numa_realloc(struct virtio_net *dev, int index)
 	struct batch_copy_elem *new_batch_copy_elems;
 	int ret;
 
-	if (dev->flags & VIRTIO_DEV_RUNNING)
-		return dev;
-
 	old_dev = dev;
 	vq = old_vq = dev->virtqueue[index];
 
+	/*
+	 * If VQ is ready, it is too late to reallocate, it certainly already
+	 * happened anyway on VHOST_USER_SET_VRING_ADRR.
+	 */
+	if (vq->ready)
+		return dev;
+
 	ret = get_mempolicy(&newnode, NULL, 0, old_vq->desc,
 			    MPOL_F_NODE | MPOL_F_ADDR);
 
@@ -558,6 +562,9 @@  numa_realloc(struct virtio_net *dev, int index)
 		rte_free(old_vq);
 	}
 
+	if (dev->flags & VIRTIO_DEV_RUNNING)
+		goto out;
+
 	/* check if we need to reallocate dev */
 	ret = get_mempolicy(&oldnode, NULL, 0, old_dev,
 			    MPOL_F_NODE | MPOL_F_ADDR);