Date: Tue, 5 May 2015 00:00:29 -0400
From: Sowmini Varadhan <sowmini.varadhan@oracle.com>
To: David Miller <davem@davemloft.net>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, chien.yen@oracle.com,
        rds-devel@oss.oracle.com, ajaykumar.hotchandani@oracle.com
Subject: Re: [PATCH 1/2] net/rds: RDS-TCP: Always create a new rds_sock for
 an incoming connection.
Message-ID: <20150505040029.GJ26844@oracle.com>
References: <c3c228cbc7f6e4a4cb8e9e0ac400aaf4ed22b927.1430421231.git.sowmini.varadhan@oracle.com>
 <20150504.144720.2228274897975931117.davem@davemloft.net>
 <20150504192908.GC26844@oracle.com>
 <20150504.162134.1761886048618680717.davem@davemloft.net>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20150504.162134.1761886048618680717.davem@davemloft.net>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1087
Lines: 27

On (05/04/15 16:21), David Miller wrote:
> 
> No table at all.
> 
> There has to be another way to notice this kind of situation, how
> for example does NFS or any other sunrpc using service handle this
> case?

NFS fixes up CLOSE_WAIT connections from xs_tcp_state_change,
so at the least, I can also do rds_conn_drop from rds_tcp_state_change,
that will avoid all the extra baggage around the new hash list.

But there's the case of the client disappearing without even sending
a FIN, and here NFS seems to recover using a notion of idle-timeout
(which applies to all idle peers, not merely the dead ones?) 

The closest analog of that would be to  set up a so_keepalive option on
the socket, but that brings in even more heuristics keepcnt, keepintvl,
keepidle. Maybe I could set these to be some very generous values
for now..

--Sowmini
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/