Date: Sat, 7 Aug 2010 13:26:08 +0000 (UTC) From: Dag-Erling Smorgrav <des@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r211016 - head/share/man/man9 Message-ID: <201008071326.o77DQ8AN052298@svn.freebsd.org>
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Author: des Date: Sat Aug 7 13:26:08 2010 New Revision: 211016 URL: http://svn.freebsd.org/changeset/base/211016 Log: Document the MEXTADD macro. MFC after: 2 weeks Modified: head/share/man/man9/mbuf.9 Modified: head/share/man/man9/mbuf.9 ============================================================================== --- head/share/man/man9/mbuf.9 Sat Aug 7 13:25:46 2010 (r211015) +++ head/share/man/man9/mbuf.9 Sat Aug 7 13:26:08 2010 (r211016) @@ -24,7 +24,7 @@ .\" .\" $FreeBSD$ .\" -.Dd March 25, 2008 +.Dd August 7, 2010 .Dt MBUF 9 .Os .\" @@ -211,7 +211,7 @@ flag bits are defined as follows: #define M_EOR 0x0004 /* end of record */ #define M_RDONLY 0x0008 /* associated data marked read-only */ #define M_PROTO1 0x0010 /* protocol-specific */ -#define M_PROTO2 0x0020 /* protocol-specific */ +#define M_PROTO2 0x0020 /* protocol-specific */ #define M_PROTO3 0x0040 /* protocol-specific */ #define M_PROTO4 0x0080 /* protocol-specific */ #define M_PROTO5 0x0100 /* protocol-specific */ @@ -238,6 +238,22 @@ types are defined as follows: #define MT_OOBDATA 15 /* expedited data */ .Ed .Pp +The available external buffer types are defined as follows: +.Bd -literal +/* external buffer types */ +#define EXT_CLUSTER 1 /* mbuf cluster */ +#define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */ +#define EXT_JUMBOP 3 /* jumbo cluster 4096 bytes */ +#define EXT_JUMBO9 4 /* jumbo cluster 9216 bytes */ +#define EXT_JUMBO16 5 /* jumbo cluster 16184 bytes */ +#define EXT_PACKET 6 /* mbuf+cluster from packet zone */ +#define EXT_MBUF 7 /* external mbuf reference (M_IOVEC) */ +#define EXT_NET_DRV 100 /* custom ext_buf provided by net driver(s) */ +#define EXT_MOD_TYPE 200 /* custom module's ext_buf type */ +#define EXT_DISPOSABLE 300 /* can throw this buffer away w/page flipping */ +#define EXT_EXTREF 400 /* has externally maintained ref_cnt ptr */ +.Ed +.Pp If the .Dv M_PKTHDR flag is set, a @@ -383,6 +399,43 @@ and internal data. See .Fn MGET for details. +.It Fn MEXTADD mbuf buf size free opt_arg1 opt_arg2 flags type +Associate externally managed data with +.Fa mbuf . +Any internal data contained in the mbuf will be discarded, and the +.Dv M_EXT flag will be set. +The +.Fa buf +and +.Fa size +arguments are the address and length, respectively, of the data. +The +.Fa free +argument points to a function which will be called to free the data +when the mbuf is freed; it is only used if +.Fa type +is +.Dv EXT_EXTREF . +The +.Fa opt_arg1 +and +.Fa opt_arg2 +arguments will be passed unmodified to +.Fa free . +The +.Fa flags +argument specifies additional +.Vt mbuf +flags; it is not necessary to specify +.Dv M_EXT . +Finally, the +.Fa type +argument specifies the type of external data, which controls how it +will be disposed of when the +.Vt mbuf +is freed. +In most cases, the correct value is +.Dv EXT_EXTREF . .It Fn MCLGET mbuf how Allocate and attach an .Vt mbuf cluster
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