On Fri, Apr 1, 2022 at 2:51 PM Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > > On Fri, Apr 01, 2022 at 02:21:52PM -0700, Roman Gushchin wrote: > > > On Apr 1, 2022, at 2:13 PM, Johannes Weiner <hannes@xxxxxxxxxxx> wrote: > > > > > > On Fri, Apr 01, 2022 at 11:39:30AM -0700, Roman Gushchin wrote: > > >> The interface you're proposing is not really extensible, so we'll likely need to > > >> introduce a new interface like memory.reclaim_ext very soon. Why not create > > >> an extensible API from scratch? > > >> > > >> I'm looking at cgroup v2 documentation which describes various interface files > > >> formats and it seems like given the number of potential optional arguments > > >> the best option is nested keyed (please, refer to the Interface Files section). > > >> > > >> E.g. the format can be: > > >> echo "1G type=file nodemask=1-2 timeout=30s" > memory.reclaim > > > > > > Yeah, that syntax looks perfect. > > > > > > But why do you think it's not extensible from the current patch? We > > > can add those arguments one by one as we agree on them, and return > > > -EINVAL if somebody passes an unknown parameter. > > > > > > It seems to me the current proposal is forward-compatible that way > > > (with the current set of keyword pararms being the empty set :-)) > > > > It wasn’t obvious to me. We spoke about positional arguments and then it wasn’t clear how to add them in a backward-compatible way. The last thing we want is a bunch of memory.reclaim* interfaces :) > > > > So yeah, let’s just describe it properly in the documentation, no code changes are needed. > > Sounds good to me! To summarize for next version: 1) Add selftests. 2) Add documentation for potential future extension, so whoever adds those features in future should follow the key-value format Roman is suggesting. Yosry, once we have agreement on the return value, please send the next version resolving these three points.
