Re: [PATCH] PCI/LINK: Account for BW notification in vector calculation

Alex G
2019-04-23T14:33:57Z

On 4/22/19 7:33 PM, Alex Williamson wrote:
> On Mon, 22 Apr 2019 19:05:57 -0500
> Alex G <mr.nuke.me@gmail.com> wrote:
>> echo 0000:07:00.0:pcie010 |
>> sudo tee /sys/bus/pci_express/drivers/pcie_bw_notification/unbind
>
> That's a bad solution for users, this is meaningless tracking of a
> device whose driver is actively managing the link bandwidth for power
> purposes.

0.5W savings on a 100+W GPU? I agree it's meaningless.

> There is nothing wrong happening here that needs to fill
> logs. I thought maybe if I enabled notification of autonomous
> bandwidth changes that it might categorize these as something we could
> ignore, but it doesn't.
> How can we identify only cases where this is
> an erroneous/noteworthy situation? Thanks,

You don't. Ethernet doesn't. USB doesn't. This logging behavior is
consistent with every other subsystem that deals with multi-speed links.
I realize some people are very resistant to change (and use very ancient
kernels). I do not, however, agree that this is a sufficient argument to
dis-unify behavior.

Alex