[dpdk-dev] [PATCH] pci: limit default numa node to used devices

[Sergio Gonzalez Monroy]

On 21/07/2017 16:37, Thomas Monjalon wrote:
> 21/07/2017 18:03, Sergio Gonzalez Monroy:
>> On 21/07/2017 15:53, Thomas Monjalon wrote:
>>> The title and the text below should explain that you move
>>> the warning log from scan to probe, thanks to a temporary
>>> negative value.
>> I thought that saying that I only check for devices managed by dpdk
>> explains the purpose,
>> and the patch itself shows the change from one file to another.
> It is obvious when you look carefully at the code, yes.
> I was just giving my help to better explain :)

Just giving my view of the commit message
If you think it can be improve,by all meansfeel free to change it :)

>>> 21/07/2017 12:11, Sergio Gonzalez Monroy:
>>>> Commit 8a04cb612589 ("pci: set default numa node for broken systems")
>>>> added logic to default to NUMA node 0 when sysfs numa_node information
>>>> was wrong or not available.
>>>>
>>>> Unfortunately there are many devices with wrong NUMA node information
>>>> that DPDK does not care about but still show warnings for them.
>>>>
>>>> Instead, only check for invalid NUMA node information for devices
>>>> managed by the DPDK.
>>>>
>>>> Signed-off-by: Sergio Gonzalez Monroy <sergio.gonzalez.monroy at intel.com>
>>> [...]
>>>> -	if (eal_parse_sysfs_value(filename, &tmp) == 0 &&
>>>> -		tmp < RTE_MAX_NUMA_NODES)
>>>> +	if (eal_parse_sysfs_value(filename, &tmp) == 0)
>>>>    		dev->device.numa_node = tmp;
>>> Why are you removing the check of the value?
>>> Are you going to accept invalid high values?
>>> This check was introduced on purpose by this commit:
>>> 	http://dpdk.org/commit/8a04cb6125
>> tmp is unsigned long type, so -1 is going to be a large number.
> Oh yes, I missed it was unsigned!
>
>> My understanding was that it was basically checking for -1 as numa_node.
>>
>> If we have valid numa_node greater than RTE_MAX_NUMA_NODES, defaulting
>> to 0 is not a good idea, is it?
>>
>> What I try to achieve with the patch is:
>> - if no numa_node avilable then parse is going to fail and we set -1.
>> - if numa_node is present but wrong, my understanding was that it would
>> be -1.
> All your explanations make sense when you realize that it is unsigned.
>
> I have one more question,
> Does it work to check for a negative value like this?
> 	if (dev->device.numa_node < 0)

numa_node is signed int type in struct rte_device, so it should work.

Regards,
Sergio