Re: [PATCH 02/12] pci-p2p: Add sysfs group to display p2pmem stats

Logan Gunthorpe
2018-01-04T23:13:09Z

On 04/01/18 02:50 PM, Bjorn Helgaas wrote:
> On Thu, Jan 04, 2018 at 12:01:27PM -0700, Logan Gunthorpe wrote:
>> Attributes display the total amount of P2P memory, the ammount available
>> and whether it is published or not.
>
> s/ammount/amount/ (also below)

Will fix.

> I wonder if "p2pdma" would be a more suggestive term? It's not really
> the *memory* that is peer-to-peer; the peer-to-peer part is referring
> to *access* to the memory.

I agree with Jason on this point. For now, it only describes the
peer-to-peer memory attributes. If we change the directory to p2pdma
then we'd have to add a mem prefix or something to each attribute.

>> @@ -82,6 +130,9 @@ static int pci_p2pmem_setup(struct pci_dev *pdev)
>> if (error)
>> goto out_pool_destroy;
>>
>> + if (sysfs_create_group(&pdev->dev.kobj, &p2pmem_group))
>> + dev_warn(&pdev->dev, "failed to create p2p sysfs group\n");
>
> Not sure the warning (by itself) is worthwhile. If we were going to
> disable the feature if sysfs_create_group() failed, that's one thing,
> but we aren't doing anything except generating a warning, which the
> user can't really do anything with. If the user is looking for the
> sysfs file, its absence will be obvious even without the message.

Unfortunately, sysfs_create_group() has the warn_unused_result flag set.
So I need to do something with the result to squash the warning. I could
just assign it to an unused variable but something seemed like it needed
to be done and printing a warning was the easiest thing...

Logan