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dd a 24 bits wide ext_flags field to m_ext by reducing ext_type

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to 8 bits.  ext_type is an enumerator and the number of types we
have is a mere dozen.

A couple of ext_types are renumbered to fit within 8 bits.

EXT_VENDOR[1-4] and EXT_EXP[1-4] types for vendor-internal and
experimental local mapping.

The ext_flags field is currently unused but has a couple of flags
already defined for future use.  Again vendor and experimental
flags are provided for local mapping.

EXT_FLAG_BITS is provided for the printf(9) %b identifier.

Initialize and copy ext_flags in the relevant mbuf functions.

Improve alignment and packing of struct m_ext on 32 and 64 archs
by carefully sorting the fields.
This commit is contained in:
andre 2013-08-24 13:15:42 +00:00
parent b9a332b6b2
commit 817be10f1c
3 changed files with 54 additions and 8 deletions
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1
sys/kern/kern_mbuf.c
View File

@ -547,6 +547,7 @@ mb_ctor_clust(void *mem, int size, void *arg, int how)
m->m_ext.ext_arg2 = NULL;
m->m_ext.ext_size = size;
m->m_ext.ext_type = type;
m->m_ext.ext_flags = 0;
m->m_ext.ref_cnt = refcnt;
}

3
sys/kern/uipc_mbuf.c
View File

@ -267,6 +267,7 @@ m_extadd(struct mbuf *mb, caddr_t buf, u_int size,
mb->m_ext.ext_arg1 = arg1;
mb->m_ext.ext_arg2 = arg2;
mb->m_ext.ext_type = type;
mb->m_ext.ext_flags = 0;
return (0);
}
@ -342,6 +343,7 @@ mb_free_ext(struct mbuf *m)
m->m_ext.ref_cnt = NULL;
m->m_ext.ext_size = 0;
m->m_ext.ext_type = 0;
m->m_ext.ext_flags = 0;
m->m_flags &= ~M_EXT;
uma_zfree(zone_mbuf, m);
}
@ -368,6 +370,7 @@ mb_dupcl(struct mbuf *n, struct mbuf *m)
n->m_ext.ext_size = m->m_ext.ext_size;
n->m_ext.ref_cnt = m->m_ext.ref_cnt;
n->m_ext.ext_type = m->m_ext.ext_type;
n->m_ext.ext_flags = m->m_ext.ext_flags;
n->m_flags |= M_EXT;
n->m_flags |= m->m_flags & M_RDONLY;
}

58
sys/sys/mbuf.h
View File

@ -138,16 +138,19 @@ struct pkthdr {
/*
* Description of external storage mapped into mbuf; valid only if M_EXT is
* set.
* Size ILP32: 28
* LP64: 48
*/
struct m_ext {
volatile u_int *ref_cnt; /* pointer to ref count info */
caddr_t ext_buf; /* start of buffer */
uint32_t ext_size; /* size of buffer, for ext_free */
uint32_t ext_type:8, /* type of external storage */
ext_flags:24; /* external storage mbuf flags */
void (*ext_free) /* free routine if not the usual */
(void *, void *);
void *ext_arg1; /* optional argument pointer */
void *ext_arg2; /* optional argument pointer */
u_int ext_size; /* size of buffer, for ext_free */
volatile u_int *ref_cnt; /* pointer to ref count info */
int ext_type; /* type of external storage */
};
/*
@ -269,7 +272,7 @@ struct mbuf {
M_PROTOFLAGS|M_HASHTYPEBITS)
/*
* External buffer types: identify ext_buf type.
* External mbuf storage buffer types.
*/
#define EXT_CLUSTER 1 /* mbuf cluster */
#define EXT_SFBUF 2 /* sendfile(2)'s sf_bufs */
@ -278,10 +281,48 @@ struct mbuf {
#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 */
#define EXT_VENDOR1 224 /* for vendor-internal use */
#define EXT_VENDOR2 225 /* for vendor-internal use */
#define EXT_VENDOR3 226 /* for vendor-internal use */
#define EXT_VENDOR4 227 /* for vendor-internal use */
#define EXT_EXP1 244 /* for experimental use */
#define EXT_EXP2 245 /* for experimental use */
#define EXT_EXP3 246 /* for experimental use */
#define EXT_EXP4 247 /* for experimental use */
#define EXT_NET_DRV 252 /* custom ext_buf provided by net driver(s) */
#define EXT_MOD_TYPE 253 /* custom module's ext_buf type */
#define EXT_DISPOSABLE 254 /* can throw this buffer away w/page flipping */
#define EXT_EXTREF 255 /* has externally maintained ref_cnt ptr */
/*
* Flags for external mbuf buffer types.
* NB: limited to the lower 24 bits.
*/
#define EXT_FLAG_EMBREF 0x000001 /* embedded ref_cnt, notyet */
#define EXT_FLAG_EXTREF 0x000002 /* external ref_cnt, notyet */
#define EXT_FLAG_NOFREE 0x000010 /* don't free mbuf to pool, notyet */
#define EXT_FLAG_VENDOR1 0x010000 /* for vendor-internal use */
#define EXT_FLAG_VENDOR2 0x020000 /* for vendor-internal use */
#define EXT_FLAG_VENDOR3 0x040000 /* for vendor-internal use */
#define EXT_FLAG_VENDOR4 0x080000 /* for vendor-internal use */
#define EXT_FLAG_EXP1 0x100000 /* for experimental use */
#define EXT_FLAG_EXP2 0x200000 /* for experimental use */
#define EXT_FLAG_EXP3 0x400000 /* for experimental use */
#define EXT_FLAG_EXP4 0x800000 /* for experimental use */
/*
* EXT flag description for use with printf(9) %b identifier.
*/
#define EXT_FLAG_BITS \
"\20\1EXT_FLAG_EMBREF\2EXT_FLAG_EXTREF\5EXT_FLAG_NOFREE" \
"\21EXT_FLAG_VENDOR1\22EXT_FLAG_VENDOR2\23EXT_FLAG_VENDOR3" \
"\24EXT_FLAG_VENDOR4\25EXT_FLAG_EXP1\26EXT_FLAG_EXP2\27EXT_FLAG_EXP3" \
"\30EXT_FLAG_EXP4"
/*
* Flags indicating hw checksum support and sw checksum requirements. This
@ -605,6 +646,7 @@ m_cljset(struct mbuf *m, void *cl, int type)
m->m_ext.ext_free = m->m_ext.ext_arg1 = m->m_ext.ext_arg2 = NULL;
m->m_ext.ext_size = size;
m->m_ext.ext_type = type;
m->m_ext.ext_flags = 0;
m->m_ext.ref_cnt = uma_find_refcnt(zone, cl);
m->m_flags |= M_EXT;