Subject: Re: CVS commit: syssrc/sys/net
To: Jason R Thorpe <thorpej@wasabisystems.com>
From: None <itojun@iijlab.net>
List: tech-net
Date: 09/27/2002 13:55:34
> > To each of 'these', I'm planning on adding this:
> >
> > /* XXX mbufs are not usually on the stack ... */
> > m.m_type = -1;
> > m.m_flags = 0;
> >
> > Before I *do* this, does anyone want to pipe up and say "bad boy, use
> > MGET() to get a _real_ mbuf for this" ?
>
>Hm.. In some sense, you do want to MGET(), because that would reduce
>stack usage. Since these code paths are used only when doing BPF taps,
>the performance penalty of the MGET() will only be incurred there, and
>if the MGET() fails, well, "so I guess we don't tap that one." :-)
or, if you are okay with MGET(), we can just M_PREPEND(), call
bpf_mtap() then m_adj().
itojun