Re: [dpdk-dev] problem: Cannot allocate memzone for ethernet port data

[Stephen Hemminger <stephen@networkplumber.org>]

On Wed, 22 Apr 2015 14:34:17 +0100
Bruce Richardson <bruce.richardson@intel.com> wrote:

> On Wed, Apr 22, 2015 at 07:36:59PM +0800, ChenXiaodong wrote:
> > Thanks for you reply!  There is actually only one NUMA node. here is what the commands return:
> > 
> 
> Hi,
> 
> there seems to be a mismatch in terms of the numa node the memory is reported
> as being on (node 0) and the numa node that the cores are detected as being on
> - as reported by the physical package id value. That's why the app is failing
> as it's looking for the memory on the wrong numa node.
> Can you try applying the patch I've just posted to change how we detect
> the numa node of a core, and see if it helps in your case.
> 
> thanks,
> /Bruce

This issue has been around a long time.
Older kernels (pre 3.3) don't have a good solution and are really broken.

Some old history:

> On Fri, 31 May 2013 11:29:09 +0200
> Damien Millescamps <damien.millescamps at 6wind.com> wrote:
> 
> > On 05/30/2013 07:12 PM, Stephen Hemminger wrote:
> > > One fix not included is the NUMA cpu assignment. The original Intel code
> > > in 1.2 incorrectly used /proc/cpuinfo to try and assign CPU's to NUMA socket.
> > > The problem is that /proc/cpuinfo physical_id corresponds to what the BIOS
> > > tells the kernel and is intended for messages only. For example, on our
> > > Dell boxes the first CPU and only CPU is reported as physical_id 1!
> > > The fix is to use sysfs instead,
> > Hi Stephen,
> > 
> > Are you using the
> > /sys/devices/system/node/nodeX/cpuX/topology/physical_package_id special
> > file ?
> > 
> > If so, then it is only usable starting from Kernel 3.3 according to this
> > fix:
> > http://git.kernel.org/cgit/linux/kernel/git/tip/tip.git/commit/?id=64be4c1c2428e148de6081af235e2418e6a66dda
> > 
> > The value returned for kernel prior to 3.3 is really not better than the
> > one from /proc/cpuinfo, so that's kind of a robbing Peter to pay Paul
> > example...
> > 
> > There is obviously a problem with the NUMA node ID detection right now
> > since both /proc/cpuinfo and /sys can return incorrect values, however
> > the node and cpu numbering is always good in the kernel boot log from
> > what I know. So there might be a better way to find the real node ID
> > whatever the kernel version used.
> > 
> > Cheers,
> 
> You need to use /sys/devices/system/cpu/cpuN/topology/physical_package_id
> as documented in kernel (Documentation/cputopology.txt).
> This was confirmed by several kernel developers including Andi Kleen from
> Intel. The value in /proc/cpuinfo comes from the APCI tables and is the value
> reported by the BIOS. There are machines that report socket 1 and 2.
> Haven't played with older kernels, but the topology information in sysfs
> has existed since 2.6.16.
> 
> The final Intel solution was to use physical_packate_id and fall back
> to /proc/cpuinfo as last resort.