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, -- Damien Millescamps
