On 9/2/22 12:10 PM, Huang, Ying wrote: > Aneesh Kumar K V <aneesh.kumar@xxxxxxxxxxxxx> writes: > >> On 9/2/22 11:42 AM, Huang, Ying wrote: >>> Aneesh Kumar K V <aneesh.kumar@xxxxxxxxxxxxx> writes: >>> >>>> On 9/2/22 11:10 AM, Huang, Ying wrote: >>>>> Aneesh Kumar K V <aneesh.kumar@xxxxxxxxxxxxx> writes: >>>>> >>>>>> On 9/2/22 10:39 AM, Wei Xu wrote: >>>>>>> On Thu, Sep 1, 2022 at 5:33 PM Huang, Ying <ying.huang@xxxxxxxxx> wrote: >>>>>>>> >>>>>>>> Aneesh Kumar K V <aneesh.kumar@xxxxxxxxxxxxx> writes: >>>>>>>> >>>>>>>>> On 9/1/22 12:31 PM, Huang, Ying wrote: >>>>>>>>>> "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxx> writes: >>>>>>>>>> >>>>>>>>>>> This patch adds /sys/devices/virtual/memory_tiering/ where all memory tier >>>>>>>>>>> related details can be found. All allocated memory tiers will be listed >>>>>>>>>>> there as /sys/devices/virtual/memory_tiering/memory_tierN/ >>>>>>>>>>> >>>>>>>>>>> The nodes which are part of a specific memory tier can be listed via >>>>>>>>>>> /sys/devices/virtual/memory_tiering/memory_tierN/nodes >>>>>>>>>> >>>>>>>>>> I think "memory_tier" is a better subsystem/bus name than >>>>>>>>>> memory_tiering. Because we have a set of memory_tierN devices inside. >>>>>>>>>> "memory_tier" sounds more natural. I know this is subjective, just my >>>>>>>>>> preference. >>>>>>>>>> >>>>>> >>>>>> >>>>>> I missed replying to this earlier. I will keep memory_tiering as subsystem name in v4 >>>>>> because we would want it to a susbsystem where all memory tiering related details can be found >>>>>> including memory type in the future. This is as per discussion >>>>>> >>>>>> https://lore.kernel.org/linux-mm/CAAPL-u9TKbHGztAF=r-io3gkX7gorUunS2UfstudCWuihrA=0g@xxxxxxxxxxxxxx >>>>> >>>>> I don't think that it's a good idea to mix 2 types of devices in one >>>>> subsystem (bus). If my understanding were correct, that breaks the >>>>> driver core convention. >>>>> >>>> >>>> All these are virtual devices .I am not sure i follow what you mean by 2 types of devices. >>>> memory_tiering is a subsystem that represents all the details w.r.t memory tiering. It shows >>>> details of memory tiers and can possibly contain details of different memory types . >>> >>> IMHO, memory_tier and memory_type are 2 kind of devices. They have >>> almost totally different attributes (sysfs file). So, we should create >>> 2 buses for them. Each has its own attribute group. "virtual" itself >>> isn't a subsystem. >> >> Considering both the details are related to memory tiering, wouldn't it be much simpler we consolidate >> them within the same subdirectory? I am still not clear why you are suggesting they need to be in different >> sysfs hierarchy. It doesn't break any driver core convention as you mentioned earlier. >> >> /sys/devices/virtual/memory_tiering/memory_tierN >> /sys/devices/virtual/memory_tiering/memory_typeN > > I think we should add > > /sys/devices/virtual/memory_tier/memory_tierN > /sys/devices/virtual/memory_type/memory_typeN > I am trying to find if there is a technical reason to do the same? > I don't think this is complex. Devices of same bus/subsystem should > have mostly same attributes. This is my understanding of driver core > convention. > I was not looking at this from code complexity point. Instead of having multiple directories with details w.r.t memory tiering, I was looking at consolidating the details within the directory /sys/devices/virtual/memory_tiering. (similar to all virtual devices are consolidated within /sys/devics/virtual/). -aneesh
