Message-ID: <1361202206.8555.34.camel@jlt4.sipsolutions.net> (sfid-20130218_164338_829975_8E814325)
Subject: Re: [RFC] design discussion: Collecting information for (non-peer)
 stations
From: Johannes Berg <johannes@sipsolutions.net>
To: Antonio Quartulli <antonio@open-mesh.com>
Cc: Simon Wunderlich <simon.wunderlich@s2003.tu-chemnitz.de>,
	"linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>,
	Thomas Pedersen <thomas@cozybit.com>,
	Marek Lindner <marek@open-mesh.com>,
	Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Date: Mon, 18 Feb 2013 16:43:26 +0100
In-Reply-To: <20130218153833.GB4162@open-mesh.com>
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	 <20130218144622.GA4162@open-mesh.com>
	 <1361201387.8555.32.camel@jlt4.sipsolutions.net>
	 <20130218153833.GB4162@open-mesh.com>
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On Mon, 2013-02-18 at 16:38 +0100, Antonio Quartulli wrote:
> On Mon, Feb 18, 2013 at 07:29:47 -0800, Johannes Berg wrote:
> > On Mon, 2013-02-18 at 15:46 +0100, Antonio Quartulli wrote:
> > 
> > > In my current implementation I created a "twin hash-table". It contains
> > > statistics for *all* the stations (peer and non-peer).
> > > 
> > > I think that instead of embedding this new struct (let's call it sta_stats) into
> > > the sta_info one, it would be easier to let them be independent (this is why I
> > > created the twin hash) and then create
> > > a pointer from the sta_info to the related sta_stats.
> > 
> > I don't really see value in that, it would only make the implementation
> > less efficient, because either you follow another pointer (sta->stats)
> > or you have to look in the other hash table. That's why I prefer
> > embedding it, we have to do the station hash table lookup anyway.
> 
> I did not like this approach because the sta_info struct is so big that
> when we want to fill the stats substruct only we will waste a lot of bytes.

I don't understand your point.

struct sta_info {
   ...
   struct stats stats;
};

struct stats_entry {
   struct hash/list/whatever;
   struct stats stats;
};

johannes