Re: [PATCH v6] numa: make node_to_cpumask_map() NUMA_NO_NODE aware

Yunsheng Lin
2019-10-30T01:58:45Z

On 2019/10/29 16:53, Michal Hocko wrote:
> On Mon 28-10-19 17:20:33, Yunsheng Lin wrote:
>> On 2019/10/12 15:40, Greg KH wrote:
>>> On Sat, Oct 12, 2019 at 02:17:26PM +0800, Yunsheng Lin wrote:
>>>> add pci and acpi maintainer
>>>> cc linux-pci@vger.kernel.org and linux-acpi@vger.kernel.org
>>>>
>>>> On 2019/10/11 19:15, Peter Zijlstra wrote:
>>>>> On Fri, Oct 11, 2019 at 11:27:54AM +0800, Yunsheng Lin wrote:
>>>>>> But I failed to see why the above is related to making node_to_cpumask_map()
>>>>>> NUMA_NO_NODE aware?
>>>>>
>>>>> Your initial bug is for hns3, which is a PCI device, which really _MUST_
>>>>> have a node assigned.
>>>>>
>>>>> It not having one, is a straight up bug. We must not silently accept
>>>>> NO_NODE there, ever.
>>>>>
>>>>
>>>> I suppose you mean reporting a lack of affinity when the node of a pcie
>>>> device is not set by "not silently accept NO_NODE".
>>>
>>> If the firmware of a pci device does not provide the node information,
>>> then yes, warn about that.
>>>
>>>> As Greg has asked about in [1]:
>>>> what is a user to do when the user sees the kernel reporting that?
>>>>
>>>> We may tell user to contact their vendor for info or updates about
>>>> that when they do not know about their system well enough, but their
>>>> vendor may get away with this by quoting ACPI spec as the spec
>>>> considering this optional. Should the user believe this is indeed a
>>>> fw bug or a misreport from the kernel?
>>>
>>> Say it is a firmware bug, if it is a firmware bug, that's simple.
>>>
>>>> If this kind of reporting is common pratice and will not cause any
>>>> misunderstanding, then maybe we can report that.
>>>
>>> Yes, please do so, that's the only way those boxes are ever going to get
>>> fixed. And go add the test to the "firmware testing" tool that is based
>>> on Linux that Intel has somewhere, to give vendors a chance to fix this
>>> before they ship hardware.
>>>
>>> This shouldn't be a big deal, we warn of other hardware bugs all the
>>> time.
>>
>> Hi, all.
>>
>> The warning for the above case has been added in [1].
>>
>> So maybe it makes sense to make node_to_cpumask_map() NUMA_NO_NODE aware
>> now?
>>
>> If Yes, this patch still can be applied to the latest linus' tree cleanly,
>> Do I need to resend it?
>>
>
> By this patch you mean http://lkml.kernel.org/r/1568724534-146242-1-git-send-email-linyunsheng@huawei.com
> right?

Yes.

>
> I would just resend it unless there is still a clear disagreement over
> it.

Ok, thanks.

Will resend it to see if there is still a disagreement over it.

>
>> [1] https://lore.kernel.org/linux-pci/1571467543-26125-1-git-send-email-linyunsheng@huawei.com/
>