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Date: Fri, 8 Jan 2016 10:24:46 -0800
From: Gleb Smirnoff <glebius@FreeBSD.org>
To: "Jonathan T. Looney" <jtl@freebsd.org>
Cc: David Wolfskill <david@catwhisker.org>, current@freebsd.org
Subject: Re: panic: sbappendstream 1 [head/amd64 @r293419]
Message-ID: <20160108182446.GZ1906@FreeBSD.org>
References: <20160108140518.GM2781@albert.catwhisker.org>
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On Fri, Jan 08, 2016 at 09:34:23AM -0500, Jonathan T. Looney wrote:
J> The likely suspect here looks like r293405, which changed uipc_send() to
J> use sbappendstream_locked() instead of sbappend_locked().
J> 
J> However, I can't explain *why* that change is causing this problem without
J> further investigation.

That is because sbappendstream() has invariant that socket buffer doesn't
have any records in it. But, if control data is sent, which is possible
for AF_UNIX, a record is made. Thus, we can't used optimized version for
AF_UNIX, only for AF_INET.

-- 
Totus tuus, Glebius.