From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: Increased multicast packet drops in 3.4
Date: Thu, 06 Sep 2012 08:26:19 +0200
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References: <20120906001108.GA6035@BohrerMBP.rgmadvisors.com>
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Cc: netdev@vger.kernel.org
To: Shawn Bohrer <sbohrer@rgmadvisors.com>
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On Wed, 2012-09-05 at 19:11 -0500, Shawn Bohrer wrote:
> One thing I find interesting is that some of the time 2
> or 3 of the 8 processes will report that they missed the exact same
> 50+ packets.  Since the other processes receive the packets I know
> that they are making it to the machine and past the driver.

Could it be that these processes missing 50+ packets provide a non
accessible area of memory and these recvmsg() calls return EFAULT ?

Are you using special memory areas, using mprotect(), or huge pages for
example ?