> 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.