On 2018-12-04 12:22 p.m., Jerome Glisse wrote: > So version is a bad prefix, what about type, prefixing target with a > type id. So that application that are looking for a certain type of > memory (which has a set of define properties) can select them. Having > a type file inside the directory and hopping application will read > that sysfs file is a recipies for failure from my point of view. While > having it in the directory name is making sure that the application > has some idea of what it is doing. Well I don't think it can be a prefix. It has to be a mask. It might be things like cache coherency, persistence, bandwidth and none of those things are mutually exclusive. >> Also, in the same vein, I think it's wrong to have the API enumerate all >> the different memory available in the system. The API should simply >> allow userspace to say it wants memory that can be accessed by a set of >> initiators with a certain set of attributes and the bind call tries to >> fulfill that or fallback on system memory/hmm migration/whatever. > > We have existing application that use topology today to partition their > workload and do load balancing. Those application leverage the fact that > they are only running on a small set of known platform with known topology > here i want to provide a common API so that topology can be queried in a > standard by application. Existing applications are not a valid excuse for poor API design. Remember, once this API is introduced and has real users, it has to be maintained *forever*, so we need to get it right. Providing users with more information than they need makes it exponentially harder to get right and support. Logan
