On Wed, May 11, 2022 at 7:42 PM Jonathan Lemon <jonathan.lemon@xxxxxxxxx> wrote: > > On 11 May 2022, at 10:33, Rafael J. Wysocki wrote: > > > On Wed, May 11, 2022 at 7:24 PM Jonathan Lemon <jonathan.lemon@xxxxxxxxx> wrote: > >> > >> This reverts commit a62d07e0006a3a3ce77041ca07f3c488ec880790. > >> > >> The change calls pxm_to_node(), which ends up returning -1 > >> (NUMA_NO_NODE) on some systems for the pci bus, as opposed > >> to the prior call to acpi_map_pxm_to_node(), which returns 0. > >> > >> The default numa node is then inherited by all pci devices, and is > >> visible in /sys/bus/pci/devices/*/numa_node > >> > >> The prior behavior shows: > >> # cat /sys/bus/pci/devices/*/numa_node | sort | uniq -c > >> 122 0 > >> > >> While the new behavior has: > >> # cat /sys/bus/pci/devices/*/numa_node | sort | uniq -c > >> 1 0 > >> 121 -1 > >> > >> While arguably NUMA_NO_NODE is correct on single-socket systems which > >> have only one numa domain, this breaks scripts that attempt to read the > >> NIC numa_node and pass that to numactl in order to pin memory allocation > >> when running applications (like iperf). E.g.: > >> > >> # numactl -p -1 iperf3 > >> libnuma: Warning: node argument -1 is out of range > >> <-1> is invalid > >> > >> Reverting this change restores the prior behavior. > > > > Well, that's not a recent commit and it fixed a real and serious issue. > > > > Isn't there a way to fix this other than reverting it? > > The userspace behavior changed - is there another way to fix things > so that a valid numa_node is returned? Well, that's my question.
