On Fri, Nov 04, 2022 at 12:18:43PM +0900, Sergey Senozhatsky wrote: > On (22/11/03 09:34), Minchan Kim wrote: > > > > My point is that we don't need to implement it atm but makes the > > > > interface to open the possibility for future extension. > > > > > > > > What do you think? > > > > > > So, as far as I understand, we don't have reason to add remove_recomp_algo > > > right now. And existing recomp_algo does not enforce any particular format, > > > it can be extended. Right now we accept "$name" but can do something like > > > "$name:$priority". The only thing that we probably need to do is rename > > > recomp_algo to either add_recomp_algo or register_recomp_algo? > > > > Yeah, I like the name and priority format. > > > > Only question is how we could support algorithm selection change > > under considering multiple secondary algorithms. > > So what I was thinking about, and I'm still in the mental model that > re-compression is a user-space event, just like writeback, extension > of recompress sysfs knob with "algo_index" (or something similar) which > will mirror algorithm priority. > > Example: > > Configure 2 alternative algos, with priority 1 and 2 > > echo "name=lz4 priority=1" > recomp_algo > echo "name=lz5 priority=2" > recomp_algo > > Recompress pages using algo 1 and algo 2 > > echo "type=huge threshold=3000 algo_idx=1" > recompress > echo "type=idle threshold=2000 algo_idx=2" > recompress > > Maybe we can even pass algo name instead of idx. Let's use name rather than index.
