topic for network card devices it in Software Archive

Programmatically detecting CPU affinity of PCI card for sandybridge

stardust496 — Fri, 22 Jun 2012 16:47:56 GMT

Folks,

With Sandybrdige, a PCI card has a natural affinity to one CPU. How can I programmatically determine which CPU it is, so that I can affinitize my program to the right CPU?

Many thanks!

Hi,

Roman_D_Intel — Thu, 20 Sep 2012 11:04:17 GMT

Hi, in Linux you can identify which processor your PCIe device is connected to by reading the "/sys/devices/[PCI root]/[PCIe function]/numa_node" or "/sys/class/[device class]/[interface]/device/numa_node" virtual files. However BIOS should support the proper ACPI feature for such detection, otherwise numa_node will report -1. Best regards, Roman

in Linux you can look it up

Roman_D_Intel — Thu, 20 Sep 2012 11:07:58 GMT

in Linux you can look it up in the /sys/devices/[PCI root]/[PCIe function]/numa_node virtual file. However BIOS should support the proper ACPI feature, otherwise you will read -1.

for network card devices it

Roman_D_Intel — Thu, 20 Sep 2012 11:10:36 GMT

for network card devices it is also available through "/sys/class/net/[interface]/device/numa_node" file.