On 04/20/2017 05:44 PM, Gavin Shan wrote: > On Thu, Apr 20, 2017 at 05:26:14PM -0700, Florian Fainelli wrote: >> On 04/20/2017 04:38 PM, Gavin Shan wrote: >>> On Thu, Apr 20, 2017 at 01:21:03PM -0400, David Miller wrote: >>>> From: Gavin Shan <gws...@linux.vnet.ibm.com> >>>> Date: Tue, 18 Apr 2017 16:51:32 +1000 >>>> >>>>> This creates /sys/kernel/debug/ncsi/<eth0>/stats to dump the NCSI >>>>> packets sent and received over all packages and channels. It's useful >>>>> to diagnose NCSI problems, especially when NCSI packages and channels >>>>> aren't probed properly. The statistics can be gained from debugfs file >>>>> as below: >>>>> >>>>> # cat /sys/kernel/debug/ncsi/eth0/stats >>>> >>>> There is no reason you cannot use ethtool statistics to provide this >>>> information to the user. >>>> >>> >>> It can be dumped by ethtool, but it's more reasonable to dump them >>> through debugfs for couple of reasons: (1) ethtool usually dumps >>> statistics collected by hardware, but this debugfs file dumps the >>> statistics of packets seen (collected) by software. They are different >>> things. Note that NCSI channel collects statistics in hardware and it's >>> not exposed or dumped by this patchset. They are candidates for ethtool. >>> (2) To expose this through ethtool relies on the availability of the tool. >>> It's nicer not to depend on it. (3) This interface can be used to check >>> the debug packet has been sent successfully through >>> /sys/kernel/debug/ncsi/eth0/pkt, >>> dumping the statistics through debugfs make this (debugging) mechanism >>> consistent. >> >> Can't you create a ncsi folder under /sys/class/net/eth0/nsci/ and then >> put your stats in there? That would at least look slightly consistent >> with what is already existing for the non-NC-SI networking stack. > > Do you think it's good place to have /sys/class/net/eth0/ncsi/pkt? > Note this file accepts commands to send NCSI comands and dumps the > corresponding response on read. Also, it's a debugging interface > and disabled (invisible) for the most time. I think all directories > and files in /sys/class/net/eth0/ should be visible and the structure > is stable all the time.
Statistics should not be debugging features having them all the time is invaluable, so in that regard they could probably be part of a sysfs interface of some kind. If this "pkt" file is special, then yes, maybe debugfs is appropriate here. It sounds like you may also want to consider doing a NC-SI generic netlink family at some point, because chances are that are you going to export more and more information over time, just like there could be additional commands/actions to be performed as well as asynchronous events. Netlink is great for that, downside is that you have to write a custom user-space tool (or extend iproute2). -- Florian
