Provide a function m_get2() that allocates a minimal mbuf that

would fit specified size. Returned mbuf may be a single mbuf,
an mbuf with a cluster from packet zone, or an mbuf with jumbo
cluster of sufficient size.

1 files changed, 48 insertions, 0 deletions

diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h
index 936ceb4..2a6c8aa 100644
--- a/sys/sys/mbuf.h
+++ b/sys/sys/mbuf.h
@@ -398,6 +398,8 @@ extern uma_zone_t	zone_ext_refcnt;
 
 static __inline struct mbuf	*m_getcl(int how, short type, int flags);
 static __inline struct mbuf	*m_get(int how, short type);
+static __inline struct mbuf	*m_get2(int how, short type, int flags,
+				    int size);
 static __inline struct mbuf	*m_gethdr(int how, short type);
 static __inline struct mbuf	*m_getjcl(int how, short type, int flags,
 				    int size);
@@ -544,6 +546,52 @@ m_getcl(int how, short type, int flags)
 }
 
 /*
+ * m_get2() allocates minimum mbuf that would fit "size" argument.
+ *
+ * XXX: This is rather large, should be real function maybe.
+ */
+static __inline struct mbuf *
+m_get2(int how, short type, int flags, int size)
+{
+	struct mb_args args;
+	struct mbuf *m, *n;
+	uma_zone_t zone;
+
+	args.flags = flags;
+	args.type = type;
+
+	if (size <= MHLEN || (size <= MLEN && (flags & M_PKTHDR) == 0))
+		return ((struct mbuf *)(uma_zalloc_arg(zone_mbuf, &args, how)));
+	if (size <= MCLBYTES)
+		return ((struct mbuf *)(uma_zalloc_arg(zone_pack, &args, how)));
+
+	if (size > MJUM16BYTES)
+		return (NULL);
+
+	m = uma_zalloc_arg(zone_mbuf, &args, how);
+	if (m == NULL)
+		return (NULL);
+
+#if MJUMPAGESIZE != MCLBYTES
+	if (size <= MJUMPAGESIZE)
+		zone = zone_jumbop;
+	else
+#endif
+	if (size <= MJUM9BYTES)
+		zone = zone_jumbo9;
+	else
+		zone = zone_jumbo16;
+
+	n = uma_zalloc_arg(zone, m, how);
+	if (n == NULL) {
+		uma_zfree(zone_mbuf, m);
+		return (NULL);
+	}
+
+	return (m);
+}
+
+/*
  * m_getjcl() returns an mbuf with a cluster of the specified size attached.
  * For size it takes MCLBYTES, MJUMPAGESIZE, MJUM9BYTES, MJUM16BYTES.
  *