[dpdk-dev] [PATCH v3] eal: Set numa node value for system which not support it.

nickcooper-zhangtonghao nic at opencloud.tech
Wed May 10 16:20:59 CEST 2017


Thanks for your review.

> On May 10, 2017, at 8:45 PM, Thomas Monjalon <thomas at monjalon.net> wrote:
> 
>> The NUMA node information for PCI devices provided through
>> sysfs is invalid for AMD Opteron(TM) Processor 62xx and 63xx
>> on Red Hat Enterprise Linux 6, and VMs on some hypervisors.
> 
> Sorry I don't understand the range of affected platforms.
> Is it only on Opteron? Opteron with RHEL6? Is it fixed in recent kernels?
> Which hypervisors? with which kernel?

I get numa info from web: https://access.redhat.com/solutions/349913 <https://access.redhat.com/solutions/349913>
and VMs which OS is CentOS 7.0 and kernel is 3.10, are running on VMware fusion.

This VMs numa node is -1. For example:

$ cat /sys/devices/pci0000:00/0000:00:18.6/numa_node
-1


>> It is good to see more checking for valid values.
> 
> If values are wrong, what can we do?
> Here you check that value is not too high.
> What about other kind of wrong values?
> 
>> Signed-off-by: Tonghao Zhang <nic at opencloud.tech <mailto:nic at opencloud.tech>>
> [...]
>> -	/* get numa node */
>> +	/* get numa node, default to 0 if not present */
>> 	snprintf(filename, sizeof(filename), "%s/numa_node",
>> 		 dirname);
>> -	if (access(filename, R_OK) != 0) {
>> -		/* if no NUMA support, set default to 0 */
>> -		dev->device.numa_node = 0;
> 
> Why removing the access() check?

I review the code of eal_parse_sysfs_value(). If the ‘filename’ cannot be accessed.
the eal_parse_sysfs_value cannot open it, and returen -1. so using eal_parse_sysfs_value is simple.

> 
>> -	} else {
>> -		if (eal_parse_sysfs_value(filename, &tmp) < 0) {
>> -			free(dev);
>> -			return -1;
>> -		}
>> +
>> +	if (eal_parse_sysfs_value(filename, &tmp) == 0 &&
>> +		tmp < RTE_MAX_NUMA_NODES)
>> 		dev->device.numa_node = tmp;
>> -	}
>> +	else
>> +		dev->device.numa_node = 0;
> 
> It would deserve at least a warning log.

Yes




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