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Sender: Minchan Kim <minchan.kim@gmail.com>
Date:   Fri, 4 Nov 2022 16:40:58 -0700
From:   Minchan Kim <minchan@kernel.org>
To:     Sergey Senozhatsky <senozhatsky@chromium.org>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Nitin Gupta <ngupta@vflare.org>, linux-kernel@vger.kernel.org,
        linux-mm@kvack.org
Subject: Re: [PATCHv4 2/9] zram: Add recompression algorithm sysfs knob
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On Sat, Nov 05, 2022 at 08:25:44AM +0900, Sergey Senozhatsky wrote:
> On (22/11/04 09:34), Minchan Kim wrote:
> > > > > 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.
> 
> OK. Any preference on the keyword? "name="? "algo="? "algorithm="?
> "compressor="? "comp="?
> 
> I want use the same keyword for recomp_algo. I sort of like "algo=",
> but not sure.

+1 with algo