Hi Reinette, On 3/12/24 10:13, Reinette Chatre wrote: > Hi Babu, > > On 3/11/2024 8:40 AM, Moger, Babu wrote: >> On 2/27/24 17:50, Reinette Chatre wrote: >>> On 2/27/2024 10:12 AM, Moger, Babu wrote: >>>> On 2/26/24 15:20, Reinette Chatre wrote: >>>>> On 2/26/2024 9:59 AM, Moger, Babu wrote: >>>>>> On 2/23/24 16:21, Reinette Chatre wrote: >>> >>>>>>> Apart from the "default behavior" there are two options to consider ... >>>>>>> (a) the "original" behavior(? I do not know what to call it) - this would be >>>>>>> where user space wants(?) to have the current non-ABMC behavior on an ABMC >>>>>>> system, where the previous "num_rmids" monitor groups can be created but >>>>>>> the counters are reset unpredictably ... should this still be supported >>>>>>> on ABMC systems though? >>>>>> >>>>>> I would say yes. For some reason user(hardware or software issues) is not >>>>>> able to use ABMC mode, they have an option to go back to legacy mode. >>>>> >>>>> I see. Should this perhaps be protected behind the resctrl "debug" mount option? >>>> >>>> The debug option gives wrong impression. It is better to keep the option >>>> open to enable the feature in normal mode. >>> >>> You mentioned that it would only be needed when there are hardware or >>> software issues ... so debug does sound appropriate. Could you please give >>> an example of how debug option gives wrong impression? Why would you want >>> users to keep using "legacy" mode on an ABMC system? >> >> We may not be able to use "-o debug" option to enable "legacy_mbm". >> With debug option it will always go to legcay mbm even if ABMC is supported. >> >> For example when ABMC is supported, I cannot mount the resctrl with debug >> option to test ABMC. >> >> I need to have a way to mount resctrl with ABMC and debug option. I can >> add "-o legacy_mbm" to enable lecacy_mbm. > > I do not think it is necessary to add a unique debug option for this. It makes the code simple. > What if instead the "-o debug" mount option exposes the "original/legacy" Can you please elaborate on this? Did you mean following command to enable legacy mode? $echo "original/legacy" /sys/fs/resctrl/info/L3_MON/mbm_assign_control It feels like a overkill and confusing. > behavior in the control file? This would enable users to only use this > behavior when in "debug" mode while still able to switch between > legacy and assigned counters. > > Reinette > -- Thanks Babu Moger
