[v4,1/7] vhost: fix missing memory table NUMA realloc

Message ID 20210617153739.178011-2-maxime.coquelin@redhat.com (mailing list archive)
State Superseded, archived
Delegated to: Maxime Coquelin
Headers
Series vhost: Fix and improve NUMA reallocation |

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Maxime Coquelin June 17, 2021, 3:37 p.m. UTC
  When the guest allocates virtqueues on a different NUMA node
than the one the Vhost metadata are allocated, both the Vhost
device struct and the virtqueues struct are reallocated.

However, reallocating the Vhost memory table was missing, which
likely causes iat least one cross-NUMA accesses for every burst
of packets.

This patch reallocates this table on the same NUMA node as the
other metadata.

Fixes: 552e8fd3d2b4 ("vhost: simplify memory regions handling")
Cc: stable@dpdk.org

Reported-by: David Marchand <david.marchand@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/vhost/vhost_user.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
  

Comments

Chenbo Xia June 18, 2021, 4:34 a.m. UTC | #1
Hi Maxime,

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Thursday, June 17, 2021 11:38 PM
> To: dev@dpdk.org; david.marchand@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>; stable@dpdk.org
> Subject: [PATCH v4 1/7] vhost: fix missing memory table NUMA realloc
> 
> When the guest allocates virtqueues on a different NUMA node
> than the one the Vhost metadata are allocated, both the Vhost
> device struct and the virtqueues struct are reallocated.
> 
> However, reallocating the Vhost memory table was missing, which
> likely causes iat least one cross-NUMA accesses for every burst
> of packets.

'at least' ?

> 
> This patch reallocates this table on the same NUMA node as the
> other metadata.
> 
> Fixes: 552e8fd3d2b4 ("vhost: simplify memory regions handling")
> Cc: stable@dpdk.org
> 
> Reported-by: David Marchand <david.marchand@redhat.com>
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  lib/vhost/vhost_user.c | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
> index 8f0eba6412..031e3bfa2f 100644
> --- a/lib/vhost/vhost_user.c
> +++ b/lib/vhost/vhost_user.c
> @@ -557,6 +557,9 @@ numa_realloc(struct virtio_net *dev, int index)

As we are realloc more things now, the comment above 'numa_realloc(XXX)'
should also be changed like:

Reallocate related data structure to make them on the same numa node as
the memory of vring descriptor.

Thanks,
Chenbo

>  		goto out;
>  	}
>  	if (oldnode != newnode) {
> +		struct rte_vhost_memory *old_mem;
> +		ssize_t mem_size;
> +
>  		VHOST_LOG_CONFIG(INFO,
>  			"reallocate dev from %d to %d node\n",
>  			oldnode, newnode);
> @@ -568,6 +571,18 @@ numa_realloc(struct virtio_net *dev, int index)
> 
>  		memcpy(dev, old_dev, sizeof(*dev));
>  		rte_free(old_dev);
> +
> +		mem_size = sizeof(struct rte_vhost_memory) +
> +			sizeof(struct rte_vhost_mem_region) * dev->mem->nregions;
> +		old_mem = dev->mem;
> +		dev->mem = rte_malloc_socket(NULL, mem_size, 0, newnode);
> +		if (!dev->mem) {
> +			dev->mem = old_mem;
> +			goto out;
> +		}
> +
> +		memcpy(dev->mem, old_mem, mem_size);
> +		rte_free(old_mem);
>  	}
> 
>  out:
> --
> 2.31.1
  
Maxime Coquelin June 18, 2021, 7:40 a.m. UTC | #2
On 6/18/21 6:34 AM, Xia, Chenbo wrote:
> Hi Maxime,
> 
>> -----Original Message-----
>> From: Maxime Coquelin <maxime.coquelin@redhat.com>
>> Sent: Thursday, June 17, 2021 11:38 PM
>> To: dev@dpdk.org; david.marchand@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>
>> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>; stable@dpdk.org
>> Subject: [PATCH v4 1/7] vhost: fix missing memory table NUMA realloc
>>
>> When the guest allocates virtqueues on a different NUMA node
>> than the one the Vhost metadata are allocated, both the Vhost
>> device struct and the virtqueues struct are reallocated.
>>
>> However, reallocating the Vhost memory table was missing, which
>> likely causes iat least one cross-NUMA accesses for every burst
>> of packets.
> 
> 'at least' ?

yes.

>>
>> This patch reallocates this table on the same NUMA node as the
>> other metadata.
>>
>> Fixes: 552e8fd3d2b4 ("vhost: simplify memory regions handling")
>> Cc: stable@dpdk.org
>>
>> Reported-by: David Marchand <david.marchand@redhat.com>
>> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
>> ---
>>  lib/vhost/vhost_user.c | 15 +++++++++++++++
>>  1 file changed, 15 insertions(+)
>>
>> diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
>> index 8f0eba6412..031e3bfa2f 100644
>> --- a/lib/vhost/vhost_user.c
>> +++ b/lib/vhost/vhost_user.c
>> @@ -557,6 +557,9 @@ numa_realloc(struct virtio_net *dev, int index)
> 
> As we are realloc more things now, the comment above 'numa_realloc(XXX)'
> should also be changed like:
> 
> Reallocate related data structure to make them on the same numa node as
> the memory of vring descriptor.

Agree, I'll put this:

"
Reallocate virtio_dev, vhost_virtqueue and related data structures to
make them on the same numa node as the memory of vring descriptor.
"

Thanks,
Maxime

> Thanks,
> Chenbo
> 
>>  		goto out;
>>  	}
>>  	if (oldnode != newnode) {
>> +		struct rte_vhost_memory *old_mem;
>> +		ssize_t mem_size;
>> +
>>  		VHOST_LOG_CONFIG(INFO,
>>  			"reallocate dev from %d to %d node\n",
>>  			oldnode, newnode);
>> @@ -568,6 +571,18 @@ numa_realloc(struct virtio_net *dev, int index)
>>
>>  		memcpy(dev, old_dev, sizeof(*dev));
>>  		rte_free(old_dev);
>> +
>> +		mem_size = sizeof(struct rte_vhost_memory) +
>> +			sizeof(struct rte_vhost_mem_region) * dev->mem->nregions;
>> +		old_mem = dev->mem;
>> +		dev->mem = rte_malloc_socket(NULL, mem_size, 0, newnode);
>> +		if (!dev->mem) {
>> +			dev->mem = old_mem;
>> +			goto out;
>> +		}
>> +
>> +		memcpy(dev->mem, old_mem, mem_size);
>> +		rte_free(old_mem);
>>  	}
>>
>>  out:
>> --
>> 2.31.1
>
  

Patch

diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c
index 8f0eba6412..031e3bfa2f 100644
--- a/lib/vhost/vhost_user.c
+++ b/lib/vhost/vhost_user.c
@@ -557,6 +557,9 @@  numa_realloc(struct virtio_net *dev, int index)
 		goto out;
 	}
 	if (oldnode != newnode) {
+		struct rte_vhost_memory *old_mem;
+		ssize_t mem_size;
+
 		VHOST_LOG_CONFIG(INFO,
 			"reallocate dev from %d to %d node\n",
 			oldnode, newnode);
@@ -568,6 +571,18 @@  numa_realloc(struct virtio_net *dev, int index)
 
 		memcpy(dev, old_dev, sizeof(*dev));
 		rte_free(old_dev);
+
+		mem_size = sizeof(struct rte_vhost_memory) +
+			sizeof(struct rte_vhost_mem_region) * dev->mem->nregions;
+		old_mem = dev->mem;
+		dev->mem = rte_malloc_socket(NULL, mem_size, 0, newnode);
+		if (!dev->mem) {
+			dev->mem = old_mem;
+			goto out;
+		}
+
+		memcpy(dev->mem, old_mem, mem_size);
+		rte_free(old_mem);
 	}
 
 out: