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. What if instead the "-o debug" mount option exposes the "original/legacy" 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
