Re: [dpdk-dev] [PATCH v4] eal: Set numa node value for system which not support it.

[Thomas Monjalon <thomas@monjalon.net>]

26/06/2017 14:50, Sergio Gonzalez Monroy:
> On 26/06/2017 10:39, Thomas Monjalon wrote:
> > 26/06/2017 11:14, Sergio Gonzalez Monroy:
> >> On 23/06/2017 14:02, Thomas Monjalon wrote:
> >>> 22/06/2017 17:15, Sergio Gonzalez Monroy:
> >>>> Just fyi, the summary line should be lowercase apart from acronyms (DPDK
> >>>> guidelines).
> >>>>
> >>>> On 11/05/2017 02:56, Tonghao Zhang wrote:
> >>>>> The NUMA node information for PCI devices provided through
> >>>>> sysfs is invalid for AMD Opteron(TM) Processor 62xx and 63xx
> >>>>> on Red Hat Enterprise Linux 6, and VMs on some hypervisors.
> >>>>> It is good to see more checking for valid values.
> >>>>>
> >>>>> Signed-off-by: Tonghao Zhang <nic@opencloud.tech>
> >>>>> ---
> >>>> IMHO the message could be slightly improved by adding some of the
> >>>> replies that you made to your v3.
> >>>> ie. Typical wrong numa node in VMs
> >>>>
> >>>> $ cat /sys/devices/pci0000:00/0000:00:18.6/numa_node
> >>>> -1
> >>> [...]
> >>>> The code changes look fine, so I leave it to Thomas regarding the commit
> >>>> message :)
> >>>>
> >>>> Acked-by: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>
> >>> Applied, thanks
> >> It looks like some systems have quite a few devices that report -1 as
> >> numa_node value causing lots of warning messages being printed.
> >> Quick fixes that come to mind would be:
> >> 1) Change log level to DEBUG
> > As it is important for performance, it should not be just for DEBUG.
> >
> >> 2) Add static var to only print the message once.
> > Yes good idea.
> >
> >> I also think that the message itself should show at least the BDF to at
> >> least know which devices are reporting bad numa_node values.
> > With the static variable, we will have only the first device BDF.
> > Is it relevant?
> >
> 
> I think it is relevant if it affects a device used by DPDK, but we don't 
> know that when doing full pci_scan.
> 
> At least on x86 platforms we usually see many PCI devices without numa_node:
> ls /sys/bus/pci/devices | xargs -n 1 -I {} head -v 
> "/sys/bus/pci/devices/{}/numa_node"
> 
> A single warning is not going to mean much if all platforms have PCI 
> devices without proper numa_node, right?
> 
> A more cleaner solution might be to leave -1 if we failed to parse 
> numa_node, then on rte_pci_probe_one_driver after checking if it is 
> blacklisted check if socket_id is -1 and show warning message defaulting 
> to 0?
> 
> I would be inclined to:
> a) leave it as it is with DEBUG log level, also showing PCI BDF (very 
> noisy in debug mode).
> b) show the warning and default to 0 in rte_pci_probe_one_driver, 
> showing only relevant devices.

Looks a good proposal Sergio!

Thanks