Hi Maciej, On 12/16/24 7:18 AM, Maciej Wieczor-Retman wrote: > Sub-NUMA Cluster divides CPUs sharing an L3 cache into separate NUMA > nodes. Systems may support splitting into either two, three, four or six > nodes. When SNC mode is enabled the effective amount of L3 cache > available for allocation is divided by the number of nodes per L3. > > It's possible to detect which SNC mode is active by comparing the number > of CPUs that share a cache with CPU0, with the number of CPUs on node0. > > Detect SNC mode once and let other tests inherit that information. > > Update CFLAGS after including lib.mk in the Makefile so that fallthrough > macro can be used. > > To check if SNC detection is reliable one can check the > /sys/devices/system/cpu/offline file. If it's empty, it means all cores > are operational and the ratio should be calculated correctly. If it has > any contents, it means the detected SNC mode can't be trusted and should > be disabled. > > Check if detection was not reliable due to offline cpus. If it was skip > running tests since the results couldn't be trusted. > > Co-developed-by: Tony Luck <tony.luck@xxxxxxxxx> > Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx> > Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@xxxxxxxxx> > --- Thank you very much. Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx> Reinette
