Hi Reinette, On 5/9/24 13:07, Reinette Chatre wrote: > Hi Babu, > > On 5/8/2024 4:29 PM, Moger, Babu wrote: >> On 5/8/24 15:41, Reinette Chatre wrote: >>> On 5/8/2024 1:07 PM, Moger, Babu wrote: >>>> On 5/7/24 15:26, Reinette Chatre wrote: >>>>> On 5/6/2024 10:18 AM, Moger, Babu wrote: >>>>>> On 5/3/24 18:24, Reinette Chatre wrote: >>>>>>> On 3/28/2024 6:06 PM, Babu Moger wrote: >>>>>>> >>>>>>>> a. Check if ABMC support is available >>>>>>>> #mount -t resctrl resctrl /sys/fs/resctrl/ >>>>>>>> >>>>>>>> #cat /sys/fs/resctrl/info/L3_MON/mbm_assign >>>>>>>> [abmc] >>>>>>>> legacy_mbm >>>>>>>> >>>>>>>> Linux kernel detected ABMC feature and it is enabled. >>>>>>> >>>>>>> Please note that this adds the "abmc" feature to the resctrl >>>>>>> *filesystem* that supports more architectures than just AMD. Calling the >>>>>>> resctrl filesystem feature "abmc" means that (a) AMD needs to be ok with >>>>>>> other architectures calling their features that are >>>>>>> similar-but-maybe-not-identical-to-AMD-ABMC "abmc", or (b) this needs >>>>>>> a new generic name. >>>>>> >>>>>> It should not a problem if other architecture calling abmc for similar >>>>>> feature. But generic name is always better if there is a suggestion. >>>>> >>>>> "should not a problem" does not instill confidence that AMD is >>>>> actually ok with this. >>>> >>>> The feature "ABMC" has been used in the public document already to refer >>>> this feature. >>>> https://www.amd.com/content/dam/amd/en/documents/processor-tech-docs/programmer-references/24594.pdf >>> >>> It is clear to me that Assignable Bandwidth Monitoring Counters (ABMC) is the >>> name of the AMD feature. The question is whether users can use the >>> same name to interact with "similar but maybe not identical" features from other >>> architectures, which is what this series enables. >>> >>>> If there comes a conflict then we can change it to amd_abmc. Didn't see >>>> any conflict at this pint. >>> >>> How do you envision this? The resctrl filesystem interface is intended to be >>> architecture neutral so it is not obvious to me how "amd_abmc" is expected >>> to look? Why would it be necessary to have different architecture specific names >>> for a similar feature from different architectures that users interact with in >>> the same way? Sounds to me as though this just needs a new non-AMD marketing name. >> >> I think I misunderstood it. >> It is not a concern to have a same name("abmc") for similar feature across >> the architectures. > > Thank you for confirming. This joins BMEC and SMBA in this regard. Yes. Sure. > >> ABMC is also kind of generic. I am open to other generic suggestions. I >> think we should have "assign" and "monitor" words in them. > > One thing we can consider is to move to a simple "enable"/"disable" > interface for events. Users do not really need to know that hardware > needs to "assign a counter" to an event for it to measure. Yes, > user space can infer some of this by the number of events that > can be "enabled" at a time, but the concept of "assign a hardware counter" > is abstract and does not directly map to (as I understand) the soft-RMID > approach for other AMD hardware. Peter reminded us a while back [1] that > "assign" has a variety of meanings, even among AMD, so we should aim to > avoid any confusion. Documentation will refer the events as enabled or disabled instead of assigned or unassigned. For example: Event flags can be one of the following: t MBM total event is enabled l MBM local event is enabled tl MBM total and local events are enabled _ None of the MBM events are enabled It is fine. > > Reinette > > [1] https://lore.kernel.org/lkml/CALPaoCjg-W3w8OKLHP_g6Evoo03fbgaOQZrGTLX6vdSLp70=SA@xxxxxxxxxxxxxx/ > > -- Thanks Babu Moger
