git: a051ca72e281 - main - Introduce m_get3()

[Kristof Provost]

The branch main has been updated by kp:

URL: https://cgit.FreeBSD.org/src/commit/?id=a051ca72e2815b9bbba1e422f5abf22bc2a01551

commit a051ca72e2815b9bbba1e422f5abf22bc2a01551
Author:     Kristof Provost <kp at FreeBSD.org>
AuthorDate: 2021-08-07 18:02:21 +0000
Commit:     Kristof Provost <kp at FreeBSD.org>
CommitDate: 2021-08-18 06:48:27 +0000

    Introduce m_get3()
    
    Introduce m_get3() which is similar to m_get2(), but can allocate up to
    MJUM16BYTES bytes (m_get2() can only allocate up to MJUMPAGESIZE).
    
    This simplifies the bpf improvement in f13da24715.
    
    Suggested by:   glebius
    Differential Revision:  https://reviews.freebsd.org/D31455
---
 share/man/man9/mbuf.9 | 11 ++++++++++-
 sys/kern/kern_mbuf.c  | 38 ++++++++++++++++++++++++++++++++++++++
 sys/net/bpf.c         |  9 +--------
 sys/sys/mbuf.h        |  1 +
 4 files changed, 50 insertions(+), 9 deletions(-)

diff --git a/share/man/man9/mbuf.9 b/share/man/man9/mbuf.9
index f6361cdc7c06..ea3f66e3e218 100644
--- a/share/man/man9/mbuf.9
+++ b/share/man/man9/mbuf.9
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd April 8, 2021
+.Dd August 8, 2021
 .Dt MBUF 9
 .Os
 .\"
@@ -73,6 +73,8 @@
 .Ft struct mbuf *
 .Fn m_get2 "int size" "int how" "short type" "int flags"
 .Ft struct mbuf *
+.Fn m_get3 "int size" "int how" "short type" "int flags"
+.Ft struct mbuf *
 .Fn m_getm "struct mbuf *orig" "int len" "int how" "short type"
 .Ft struct mbuf *
 .Fn m_getjcl "int how" "short type" "int flags" "int size"
@@ -577,6 +579,13 @@ with enough space to hold specified amount of data.
 If the size is is larger than
 .Dv MJUMPAGESIZE , NULL
 will be returned.
+.It Fn m_get3 size how type flags
+Allocate an
+.Vt mbuf
+with enough space to hold specified amount of data.
+If the size is is larger than
+.Dv MJUM16BYTES, NULL
+will be returned.
 .It Fn m_getm orig len how type
 Allocate
 .Fa len
diff --git a/sys/kern/kern_mbuf.c b/sys/kern/kern_mbuf.c
index ae4aa7d7e96a..123985a7dec2 100644
--- a/sys/kern/kern_mbuf.c
+++ b/sys/kern/kern_mbuf.c
@@ -1371,6 +1371,44 @@ m_get2(int size, int how, short type, int flags)
 	return (m);
 }
 
+/*
+ * m_get3() allocates minimum mbuf that would fit "size" argument.
+ * Unlike m_get2() it can allocate clusters up to MJUM16BYTES.
+ */
+struct mbuf *
+m_get3(int size, int how, short type, int flags)
+{
+	struct mb_args args;
+	struct mbuf *m, *n;
+	uma_zone_t zone;
+
+	if (size <= MJUMPAGESIZE)
+		return (m_get2(size, how, type, flags));
+
+	if (size > MJUM16BYTES)
+		return (NULL);
+
+	args.flags = flags;
+	args.type = type;
+
+	m = uma_zalloc_arg(zone_mbuf, &args, how);
+	if (m == NULL)
+		return (NULL);
+
+	if (size <= MJUM9BYTES)
+		zone = zone_jumbo9;
+	else
+		zone = zone_jumbo16;
+
+	n = uma_zalloc_arg(zone_jumbop, m, how);
+	if (n == NULL) {
+		m_free_raw(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.
diff --git a/sys/net/bpf.c b/sys/net/bpf.c
index ff14152c086c..77c85cc91aae 100644
--- a/sys/net/bpf.c
+++ b/sys/net/bpf.c
@@ -644,14 +644,7 @@ bpf_movein(struct uio *uio, int linktype, struct ifnet *ifp, struct mbuf **mp,
 		return (EMSGSIZE);
 
 	/* Allocate a mbuf for our write, since m_get2 fails if len >= to MJUMPAGESIZE, use m_getjcl for bigger buffers */
-	if (len < MJUMPAGESIZE)
-		m = m_get2(len, M_WAITOK, MT_DATA, M_PKTHDR);
-	else if (len <= MJUM9BYTES)
-		m = m_getjcl(M_WAITOK, MT_DATA, M_PKTHDR, MJUM9BYTES);
-	else if (len <= MJUM16BYTES)
-		m = m_getjcl(M_WAITOK, MT_DATA, M_PKTHDR, MJUM16BYTES);
-	else
-		m = NULL;
+	m = m_get3(len, M_WAITOK, MT_DATA, M_PKTHDR);
 	if (m == NULL)
 		return (EIO);
 	m->m_pkthdr.len = m->m_len = len;
diff --git a/sys/sys/mbuf.h b/sys/sys/mbuf.h
index 2936966f6acc..58ada4d0b7b2 100644
--- a/sys/sys/mbuf.h
+++ b/sys/sys/mbuf.h
@@ -829,6 +829,7 @@ struct mbuf	*m_fragment(struct mbuf *, int, int);
 void		 m_freem(struct mbuf *);
 void		 m_free_raw(struct mbuf *);
 struct mbuf	*m_get2(int, int, short, int);
+struct mbuf	*m_get3(int, int, short, int);
 struct mbuf	*m_getjcl(int, short, int, int);
 struct mbuf	*m_getm2(struct mbuf *, int, int, short, int);
 struct mbuf	*m_getptr(struct mbuf *, int, int *);