From owner-freebsd-net  Tue Oct 23 12:17:14 2001
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Date: Tue, 23 Oct 2001 15:17:04 -0400 (EDT)
From: Garrett Wollman <wollman@khavrinen.lcs.mit.edu>
Message-Id: <200110231917.f9NJH4T32996@khavrinen.lcs.mit.edu>
To: Luigi Rizzo <rizzo@aciri.org>
Cc: net@FreeBSD.ORG
Subject: performance issues with M_PREPEND on clusters
In-Reply-To: <20011023110307.A34494@iguana.aciri.org>
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<<On Tue, 23 Oct 2001 11:03:07 -0700, Luigi Rizzo <rizzo@aciri.org> said:

> Similar things could be done in m_pullup() to avoid the
> extra allocation.

Can't be done in m_pullup: the whole purpose of m_pullup is to
*guarantee* that the data in question will never be shared.  It might
be worth having a new interface which doesn't provide such a
guarantee.

-GAWollman


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