Hi Reinette, On 3/19/25 15:53, Reinette Chatre wrote: > Hi Babu and Peter, > > On 3/17/25 4:00 PM, Moger, Babu wrote: >> Hi Peter, >> >> On 3/17/2025 11:27 AM, Peter Newman wrote: >>> Hi Reinette, >>> >>> On Thu, Mar 13, 2025 at 10:22 PM Reinette Chatre >>> <reinette.chatre@xxxxxxxxx> wrote: >>>> >>>> Hi Babu, >>>> >>>> On 3/13/25 1:13 PM, Moger, Babu wrote: >>>>> On 3/13/25 11:08, Reinette Chatre wrote: >>>>>> On 3/12/25 11:14 AM, Moger, Babu wrote: >>>>>>> On 3/12/25 12:14, Reinette Chatre wrote: >>>>>>>> On 3/12/25 9:03 AM, Moger, Babu wrote: >>>>>>>>> On 3/12/25 10:07, Reinette Chatre wrote: >>>> >>>> >>>>> Here are the steps. Just copying steps from Peters proposal. >>>>> https://lore.kernel.org/lkml/CALPaoCiii0vXOF06mfV=kVLBzhfNo0SFqt4kQGwGSGVUqvr2Dg@xxxxxxxxxxxxxx/ >>>> >>>> Thank you very much for detailing the steps. It is starting the fall into place >>>> for me. >>>> >>>>> >>>>> >>>>> 1. Mount the resctrl >>>>> mount -t resctrl resctrl /sys/fs/resctrl >>>> >>>> I assume that on ABMC system the plan remains to have ABMC enabled by default, which >>>> will continue to depend on BMEC. >>>> >>>> How would the k existing BMEC implementation be impacted in this case? >>>> >>>> Without any changes to BMEC support the mbm_total_bytes_config and mbm_local_bytes_config >>>> files will remain and user space may continue to use them to change the event >>>> configurations with confusing expecations/results on an ABMC system. >>>> >>>> One possibility may be that a user may see below on ABMC system even if BMEC is supported: >>>> # cat /sys/fs/resctrl/info/L3_MON/mon_features >>>> llc_occupancy >>>> mbm_total_bytes >>>> mbm_local_bytes >>>> >>>> With the above a user cannot be expected to want to interact with mbm_total_bytes_config >>>> and mbm_local_bytes_config, which may be the simplest to do. >>> >>> How about making mbm_local_bytes and mbm_total_bytes always be >>> configured using mbm_{local,total}_bytes_config and only allowing the >>> full ABMC configurability on user-defined configurations. This could >>> resolve the issue of backwards compatibility with the BMEC files and >>> remove the need for the user opting-in to ABMC mode. > > hmmm, yes, backward compatibility is a big issue with an earlier suggestion > from me. Users with scripts/tools using mbm_{local,total}_bytes_config > would expect that to continue to work on systems that support BMEC. > resctrl could continue to use mbm_{local,total}_bytes_config > even though the inconsistent interface is not ideal > >> >> There is no opt-in mode. ABMC will be enabled by default if supported. >> Users will have option to go back to legacy mode. > > I assume there will still be the opt-in for automatic counter assignment > on monitor group creation (mkdir)? Yes. It will be available. -- Thanks Babu Moger
