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Date: Sun, 24 Nov 2013 15:15:49 +0100
From: Vladimir Murzin <murzin.v@gmail.com>
To: Dan Streetman <ddstreet@ieee.org>
Cc: linux-mm@kvack.org, Seth Jennings <sjennings@variantweb.net>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Bob Liu <bob.liu@oracle.com>, Minchan Kim <minchan@kernel.org>,
        Weijie Yang <weijie.yang@samsung.com>
Subject: Re: [PATCH] mm/zswap: change params from hidden to ro
Message-ID: <20131124141545.GA2106@hp530>
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On Fri, Nov 22, 2013 at 12:18:01PM -0500, Dan Streetman wrote:
> On Fri, Nov 22, 2013 at 2:38 AM, Vladimir Murzin <murzin.v@gmail.com> wrote:
> > On Wed, Nov 20, 2013 at 12:52:47PM -0500, Dan Streetman wrote: > On Wed, Nov
> > 20, 2013 at 12:33 PM, Vladimir Murzin <murzin.v@gmail.com> wrote: > > Hi Dan!
> >> >
> >> > On Wed, Nov 20, 2013 at 11:38:42AM -0500, Dan Streetman wrote:
> >> >> The "compressor" and "enabled" params are currently hidden,
> >> >> this changes them to read-only, so userspace can tell if
> >> >> zswap is enabled or not and see what compressor is in use.
> >> >
> >> > Could you elaborate more why this pice of information is necessary for
> >> > userspace?
> >>
> >> For anyone interested in zswap, it's handy to be able to tell if it's
> >> enabled or not ;-)  Technically people can check to see if the zswap
> >> debug files are in /sys/kernel/debug/zswap, but I think the actual
> >> "enabled" param is more obvious.  And the compressor param is really
> >> the only way anyone from userspace can see what compressor's being
> >> used; that's helpful to know for anyone that might want to be using a
> >> non-default compressor.
> >
> > So, it is needed for user not userspace? I tend to think that users are smart
> > enough to check cmdline for that.
> 
> Let's try a different way.  Can you explain what the problem is with
> making these params user-readable?

This patch is absolutely neutral for me - nothing bad and nothing good. I've just
been curious what argument for this patch you have except "let it be".

Thanks
Vadimir