diff options
| author | Bret Lambert <blambert@cvs.openbsd.org> | 2009-06-02 00:05:14 +0000 |
|---|---|---|
| committer | Bret Lambert <blambert@cvs.openbsd.org> | 2009-06-02 00:05:14 +0000 |
| commit | 2b91b760441f05ccee1184ef7c4bbf0c4c8a4860 (patch) | |
| tree | 639c0e7abfde96a688ad12e53ff90ea37c88201f /sys/kern | |
| parent | e1217a8eae85a6fee4335dbdd63014714e193e30 (diff) | |
Move M_PREPEND macro code to be entirely into m_prepend the function;
calling M_PREPEND is now #define'd to be calling m_prepend.
Shaves an unknown but assumed-to-be-nontrivial amount from the kernel.
ok claudio@ henning@(who may have had to okay this twice to get me to notice)
Diffstat (limited to 'sys/kern')
| -rw-r--r-- | sys/kern/uipc_mbuf.c | 31 |
1 files changed, 18 insertions, 13 deletions
diff --git a/sys/kern/uipc_mbuf.c b/sys/kern/uipc_mbuf.c index 1d12b78d771..acd7a7f4330 100644 --- a/sys/kern/uipc_mbuf.c +++ b/sys/kern/uipc_mbuf.c @@ -1,4 +1,4 @@ -/* $OpenBSD: uipc_mbuf.c,v 1.119 2009/03/02 23:52:18 dlg Exp $ */ +/* $OpenBSD: uipc_mbuf.c,v 1.120 2009/06/02 00:05:13 blambert Exp $ */ /* $NetBSD: uipc_mbuf.c,v 1.15.4.1 1996/06/13 17:11:44 cgd Exp $ */ /* @@ -540,9 +540,7 @@ m_defrag(struct mbuf *m, int how) */ /* - * Lesser-used path for M_PREPEND: - * allocate new mbuf to prepend to chain, - * copy junk along. + * Ensure len bytes of contiguous space at the beginning of the mbuf chain */ struct mbuf * m_prepend(struct mbuf *m, int len, int how) @@ -552,17 +550,24 @@ m_prepend(struct mbuf *m, int len, int how) if (len > MHLEN) panic("mbuf prepend length too big"); - MGET(mn, how, m->m_type); - if (mn == NULL) { - m_freem(m); - return (NULL); + if (M_LEADINGSPACE(m) >= len) { + m->m_data -= len; + m->m_len += len; + } else { + MGET(mn, how, m->m_type); + if (mn == NULL) { + m_freem(m); + return (NULL); + } + if (m->m_flags & M_PKTHDR) + M_MOVE_PKTHDR(mn, m); + mn->m_next = m; + m = mn; + MH_ALIGN(m, len); + m->m_len = len; } if (m->m_flags & M_PKTHDR) - M_MOVE_PKTHDR(mn, m); - mn->m_next = m; - m = mn; - MH_ALIGN(m, len); - m->m_len = len; + m->m_pkthdr.len += len; return (m); } |