On Fri, Apr 1, 2022 at 2:21 PM Roman Gushchin <roman.gushchin@xxxxxxxxx> 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. > > I agree this is a better syntax than positional arguments. The latter would require a default value be specified for each earlier argument if we just want to provide a custom value for a later argument. > > 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.
