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 16:41:43 +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 16:18 +0200, Jesper Dangaard Brouer a =C3=
=A9crit :
> Network driver igb: Improve the accuracy of stats in /proc/net/dev, b=
y
> updating the adapter stats when reading /proc/net/dev.  Currently the
> stats are updated by the watchdog timer every 2 sec, or when getting
> stats via ethtool -S.
>=20
> A number of userspace apps read these /proc/net/dev stats every secon=
d,
> e.g. ifstat, which then gives a perceived very bursty traffic pattern=
,
> which is actually false.
>=20
> Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk>

Unfortunately this is racy with igb_watchdog_task()

igb_update_stats() must be called under protection of a lock.