Date: Wed, 1 Dec 1999 15:27:45 -0800 (PST) From: Archie Cobbs <archie@whistle.com> To: gibbs@FreeBSD.org (Justin T. Gibbs) Cc: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/kern uipc_mbuf.c src/sys/sys mbuf.h Message-ID: <199912012327.PAA45003@bubba.whistle.com> In-Reply-To: <199912012141.OAA00992@caspian.plutotech.com> from "Justin T. Gibbs" at "Dec 1, 1999 02:41:51 pm"
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Justin T. Gibbs writes: > > Modified files: > > sys/kern uipc_mbuf.c > > sys/sys mbuf.h > > Log: > > The functions m_copym() and m_copypacket() return read-only copies, > > because in the case of mbuf clusters they only increment the reference > > count rather than actually copying the data. > > > > Add comments to this effect, and add a new routine called m_dup() that > > returns a real, writable copy of an mbuf chain. > > How does this work in a 0 copy system? Not sure what a '0 copy system' is.. Basically all it does is create a completely new mbuf chain containing the same data as the original. Definitely at least 1 copy :-) You rarely need this, but 'ipfw tee' is one of those cases. -Archie ___________________________________________________________________________ Archie Cobbs * Whistle Communications, Inc. * http://www.whistle.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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