Hi Babu, On 06/08/2024 23:00, Babu Moger wrote: > Introduce interface to switch between ABMC and legacy modes. > > By default ABMC is enabled on boot if the feature is available. > Provide the interface to go back to legacy mode if required. I may have missed it on an earlier version ... why would anyone want the non-ABMC behaviour on hardware that requires it: counters randomly reset and randomly return 'Unavailable'... is that actually useful? You default this to on, so there isn't a backward compatibility argument here. It seems like being able to disable this is a source of complexity - is it needed? For MPAM I'm looking at enabling this on any platform that is short of monitors. If user-space disables it I don't have a "at random" hardware behaviour to fall back on - its extra work to invent a behaviour I'm not sure is useful... > $ cat /sys/fs/resctrl/info/L3_MON/mbm_mode > [mbm_cntr_assign] > legacy > > To enable the "mbm_cntr_assign" mode: > $ echo "mbm_cntr_assign" > /sys/fs/resctrl/info/L3_MON/mbm_mode > > To enable the legacy monitoring feature: > $ echo "legacy" > /sys/fs/resctrl/info/L3_MON/mbm_mode > > MBM event counters will reset when mbm_mode is changed. Thanks, James
