Re: [PATCH] net/af_xdp: parse numa node id from sysfs

[Ferruh Yigit <ferruh.yigit@amd.com>]

On 1/17/2023 1:35 AM, Du, Frank wrote:

Moved down, please don't top post.

>> 
>> -----Original Message-----
>> From: Ferruh Yigit, <ferruh.yigit@amd.com> 
>> Sent: Monday, January 16, 2023 9:15 PM
>> To: Du, Frank <frank.du@intel.com>; Loftus, Ciara <ciara.loftus@intel.com>
>> Cc: dev@dpdk.org
>> Subject: Re: [PATCH] net/af_xdp: parse numa node id from sysfs
>> 
>> On 12/12/2022 12:48 AM, Frank Du wrote:
>>> Get from /sys/class/net/{if}/device/numa_node.
>>>
>>> Signed-off-by: Frank Du <frank.du@intel.com>
>>> ---
>>>  drivers/net/af_xdp/rte_eth_af_xdp.c | 17 ++++++++++++++---
>>>  1 file changed, 14 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c 
>>> b/drivers/net/af_xdp/rte_eth_af_xdp.c
>>> index b6ec9bf490..38b9d36ab5 100644
>>> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
>>> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
>>> @@ -39,6 +39,7 @@
>>>  #include <rte_power_intrinsics.h>
>>>  
>>>  #include "compat.h"
>>> +#include "eal_filesystem.h"
>>>  
>>>  #ifndef SO_PREFER_BUSY_POLL
>>>  #define SO_PREFER_BUSY_POLL 69
>>> @@ -2038,9 +2039,6 @@ rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
>>>  		return -EINVAL;
>>>  	}
>>>  
>>> -	if (dev->device.numa_node == SOCKET_ID_ANY)
>>> -		dev->device.numa_node = rte_socket_id();
>>> -
>>>  	if (parse_parameters(kvlist, if_name, &xsk_start_queue_idx,
>>>  			     &xsk_queue_cnt, &shared_umem, prog_path,
>>>  			     &busy_budget, &force_copy) < 0) { @@ -2053,6 +2051,19 @@ 
>>> rte_pmd_af_xdp_probe(struct rte_vdev_device *dev)
>>>  		return -EINVAL;
>>>  	}
>>>  
>>> +	/* get numa node id from net sysfs */
>>> +	if (dev->device.numa_node == SOCKET_ID_ANY) {
>>> +		unsigned long numa = 0;
>>> +		char numa_path[PATH_MAX];
>>> +
>>> +		snprintf(numa_path, sizeof(numa_path), "/sys/class/net/%s/device/numa_node",
>>> +			 if_name);
>>> +		if (eal_parse_sysfs_value(numa_path, &numa) != 0)
>>> +			dev->device.numa_node = rte_socket_id();
>>> +		else
>>> +			dev->device.numa_node = numa;
>>> +	}
>>> +
>>>  	busy_budget = busy_budget == -1 ? ETH_AF_XDP_DFLT_BUSY_BUDGET :
>>>  					busy_budget;
>>>  
>> 
>> Hi Frank,
>> 
>> It looks reasonable to set virtual DPDK af_xdp device socket to actual underlying device socket. And as I checked quickly, it works as expected.
>> 
>> But what is the impact and motivation of the patch? In other words why you are doing this patch and what output you are expecting as a result?
>> Did you able to do any performance testing, and are you observing any difference before and after this test?
>> 
> 
> Hi ferruh,
> 
> Our application use rte_eth_dev_socket_id to query the socket that a NIC port connected, then allocate lcore/memory according to this affinity.
> 
> The remote memory access is really slow compared to local.
> 

As you observing any performance gain after change? If so, how much?