From mboxrd@z Thu Jan  1 00:00:00 1970
From: Robin Holt <holt@sgi.com>
Subject: sysctl_{tcp,udp,sctp}_mem overflow on 16TB system.
Date: Fri, 1 Oct 2010 14:39:58 -0500
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Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
	linux-decnet-user@lists.sourceforge.net, linux-sctp@vger.kernel.org
To: "David S. Miller" <davem@davemloft.net>,
	Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
	"Pekka Savola (ipv6)" <pekkas@netcore.fi>,
	James Morris <jmorris@namei.org>,
	Hideaki YOSHIFUJI <yosh
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On a 16TB system, we noticed that sysctl_tcp_mem[2] and sysctl_udp_mem[2]
were negative.  Code review indicates that the same should occur with
sysctl_sctp_mem[2].

There are a couple ways we could address this.  The one which appears most
reasonable would be to change the struct proto defintion for sysctl_mem
from an int to a long and handle all the associated fallout.

An alternative is to limit the calculation to 1/2 INT_MAX.  The downside
being that the administrator could not tune the system to use more than
INT_MAX memory when much more is available.

Is there a compelling reason to not change the structure's definition
over to longs instead of ints and deal with the fallout from that change?

Thanks,
Robin Holt