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| author | luigi <luigi@FreeBSD.org> | 2001-12-14 17:31:58 +0000 |
|---|---|---|
| committer | luigi <luigi@FreeBSD.org> | 2001-12-14 17:31:58 +0000 |
| commit | 34c1073cfc26bcfb3b31de63c71ab21bcd44065e (patch) | |
| tree | 8672d993580f6e21ce7168dc25161beac5dc7887 | |
| parent | 6829d5b1436ba592199aaf5d484f887d3064c9a9 (diff) | |
| download | FreeBSD-src-34c1073cfc26bcfb3b31de63c71ab21bcd44065e.zip FreeBSD-src-34c1073cfc26bcfb3b31de63c71ab21bcd44065e.tar.gz | |
Let M_LEADINGSPACE write into non-shared mbufs.
A similar thing has been in -stable for weeks and is completely safe.
This has very good performance implications as it saves some data
copying, and sometimes avoids triggering performance bugs in devices
(such as the "dc" and other Tulip clones) which do not like scattered
data.
| -rw-r--r-- | sys/sys/mbuf.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h index 1f18173..e563f05 100644 --- a/sys/sys/mbuf.h +++ b/sys/sys/mbuf.h @@ -360,7 +360,7 @@ struct mbstat { */ #define M_LEADINGSPACE(m) \ ((m)->m_flags & M_EXT ? \ - /* (m)->m_data - (m)->m_ext.ext_buf */ 0 : \ + (M_WRITABLE(m) ? (m)->m_data - (m)->m_ext.ext_buf : 0): \ (m)->m_flags & M_PKTHDR ? (m)->m_data - (m)->m_pktdat : \ (m)->m_data - (m)->m_dat) |
