From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [net-next PATCH] igb: update adapter stats when reading
 /proc/net/dev.
Date: Tue, 05 Oct 2010 23:01:19 +0200
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Cc: "David S. Miller" <davem@davemloft.net>, netdev@vger.kernel.org,
	Jeff Kirsher <jeffrey.t.kirsher@intel.com>
To: Jesper Dangaard Brouer <hawk@comx.dk>
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Le mardi 05 octobre 2010 =C3=A0 17:19 +0200, Eric Dumazet a =C3=A9crit =
:
> Le mardi 05 octobre 2010 =C3=A0 16:53 +0200, Jesper Dangaard Brouer a=
 =C3=A9crit :
>=20
> > Its already racy, because "ethtool -S" reads out the stats immediat=
ely,
> > and thus races with the timer.
> >=20
> > See: igb_ethtool.c
> >  igb_get_ethtool_stats() invoke igb_update_stats(adapter);
> >=20
>=20
> You would be surprised how many bugs are waiting to be found and
> fixed ;)
>=20
>=20

I took a look at igb stats, and it appears they also are racy on 32bit
arches. igb uses u64 counters, with no synchronization between
producers(writers) and consumers(readers).

Some fixes are needed ;)