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Date: Mon, 5 Jun 1995 19:38:30 -0700
From: Eric Hoffman <hoffman@Ipsilon.COM>
Message-Id: <199506060238.TAA06992@servo.ipsilon.com>
To: hackers@freebsd.org
Subject: external storage for mbufs
Sender: hackers-owner@freebsd.org
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  #ifdef notyet
  #define       MFREE(m, n) \
  ....general purpose deallocator which uses ext_free function pointer..
  #else /* notyet */
  #define       MFREE(m, nn) \
  ....deallocator which assumes M_EXT is always part of the cluster system...
  #endif

could someone lend some context to why the following code from
mbuf.h is conditionalized the way it is?

an idle recompile with the new code caused damage...what other
conditions in the system exist that make it not yet ready?