Re: [PATCH 1/9] PCI: sysfs: Export available PCIe bandwidth

[Alex G.]

On 09/05/2018 02:26 AM, Stephen Hemminger wrote:
> On Mon,  3 Sep 2018 13:02:28 -0500
> Alexandru Gagniuc <mr.nuke.me@xxxxxxxxx> wrote:
>
> > For certain bandwidth-critical devices (e.g. multi-port network cards)
> > it is useful to know the available bandwidth to the root complex. This
> > information is only available via the system log, which doesn't
> > account for link degradation after probing.
> >
> > With a sysfs attribute, we can computes the bandwidth on-demand, and
> > will detect degraded links.
> >
> > Signed-off-by: Alexandru Gagniuc <mr.nuke.me@xxxxxxxxx>
>
> In other places (like /sys/class/net/eth0/speed) only the raw value is printed
> without suffix.  The general convention in sysfs is that it should be one value
> per file and in more raw format.  So why not just print it in bits/sec without
> suffix?

I wanted to be consistent with other PCIe exports that use units.For 
example:

/sys/devices/pci0000:3a/0000:3a:00.0/0000:3b:00.0/0000:3c:05.0/max_link_speed:8 
GT/s
/sys/devices/pci0000:3a/0000:3a:00.0/0000:3b:00.0/0000:3c:05.0/current_link_speed:2.5 
GT/s
/sys/bus/pci/slots/182/cur_bus_speed:2.5 GT/s PCIe
/sys/bus/pci/slots/182/max_bus_speed:8.0 GT/s PCIe