Hi Reinette, On 2/23/24 11:17, Reinette Chatre wrote: > > > On 2/20/2024 12:48 PM, Moger, Babu wrote: >> On 2/20/24 09:21, James Morse wrote: >>> On 19/01/2024 18:22, Babu Moger wrote: > >>>> e. Enable ABMC mode. >>>> >>>> #echo 1 > /sys/fs/resctrl/info/L3_MON/mbm_assign_enable >>>> #cat /sys/fs/resctrl/info/L3_MON/mbm_assign_enable >>>> 1 >>> >>> Why does this mode need enabling? Can't it be enabled automatically on hardware that >>> supports it, or enabled implicitly when the first assignment attempt arrives? >>> >>> I guess this is really needed for a reset - could we implement that instead? This way >>> there isn't an extra step user-space has to do to make the assignments work. >> >> Mostly the new features are added as an opt-in method. So, kept it that >> way. If we enable this feature automatically, then we have provide an >> option to disable it. >> > > At the same time it sounds to me like ABMC can improve current users' > experience without requiring them to do anything. This sounds appealing. > For example, if I understand correctly, it may be possible to start resctrl > with ABMC enabled by default and the number of monitoring groups (currently > exposed to user space via "num_rmids") limited to the number of counters > supported by ABMC. Existing users would then by default obtain better behavior > of counters not resetting. Yes, I like the idea. But i will break compatibility with pqos tool(intel_cmt_cat utility). pqos tool monitoring will not work without supporting ABMC enablement in the tool. ABMC feature requires an extra step to assign the counters for monitor to work. > > The "new feature" could then be viewed as adding support for more monitoring > groups than what hardware can support concurrently. > > Reinette -- Thanks Babu Moger
