[PATCH 3/3] tree: add attribute numa_nodes for NVMe path object

[Hannes Reinecke]

On 4/8/25 13:42, Daniel Wagner wrote:
> On Tue, Apr 08, 2025 at 07:58:40AM +0200, Hannes Reinecke wrote:
>> On 4/7/25 17:19, Daniel Wagner wrote:
>>> On Mon, Apr 07, 2025 at 07:49:41PM +0530, Nilay Shroff wrote:
>>>> Both approaches — either adding a no-cache flag or introducing dedicated
>>>> __no_cached APIs — would work. However, in my opinion, we should aim to
>>>> use a consistent method across both libnvme 1.x and 2.x versions.
>>>
>>> There will be a lot of API changes for 2.x to address all the silly
>>> mistakes. That's way it will be a major version change.
>>>
>>>> As we discussed during LSFMM, if we plan to implement an "nvme top" command,
>>>> we would need non-cached versions of these APIs even for nvme-cli.
>>>
>>> Yes, that is why I brought up this discussion. For such a command we
>>> would need non cached versions. And I realize that we would need this
>>> feature also for other commands. So it's not just the queue depth which
>>> changes. Maybe we should just not try to add this feature to 1.x and
>>> rather start the 2.x project.
>>>
>>>> So, using the same mechanism for both versions makes sense. Otherwise,
>>>> we’d also have to maintain different logic in nvme top depending on
>>>> the libnvme version, which adds unnecessary complexity.
>>>
>>> I don't see a big problem here. Either use the 1.x or 2.x.
>>
>> Why don't we make this option as non-cached by default?
>> In the end, there is limited usability in having it cached.
> 
> Sure, this is also fine. I suppose there will be some more conversion
> from cached to non-cached necessary for the 'nvme top' feature.

And I dimly remember I did some of this work already during the python
binding work (where some attributes changed during the lifetime of the
tree). Not sure what happened to that, though.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
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