Merge the //depot/user/yar/vlan branch into CVS. It contains some collective

work by yar, thompsa and myself. The checksum offloading part also involves
work done by Mihail Balikov.

The most important changes:

o   Instead of global linked list of all vlan softc use a per-trunk
  hash. The size of hash is dynamically adjusted, depending on
  number of entries. This changes struct ifnet, replacing counter
  of vlans with a pointer to trunk structure. This change is an
  improvement for setups with big number of VLANs, several interfaces
  and several CPUs. It is a small regression for a setup with a single
  VLAN interface.
    An alternative to dynamic hash is a per-trunk static array with
  4096 entries, which is a compile time option - VLAN_ARRAY. In my
  experiments the array is not an improvement, probably because such
  a big trunk structure doesn't fit into CPU cache.
o   Introduce an UMA zone for VLAN tags. Since drivers depend on it,
  the zone is declared in kern_mbuf.c, not in optional vlan(4) driver.
  This change is a big improvement for any setup utilizing vlan(4).
o   Use rwlock(9) instead of mutex(9) for locking. We are the first
  ones to do this! :)
o   Some drivers can do hardware VLAN tagging + hardware checksum
  offloading. Add an infrastructure for this. Whenever vlan(4) is
  attached to a parent or parent configuration is changed, the flags
  on vlan(4) interface are updated.

In collaboration with:	yar, thompsa
In collaboration with:	Mihail Balikov <mihail.balikov interbgc.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/sys/kern/kern_mbuf.c b/sys/kern/kern_mbuf.c
index 514eca4..8f5b919 100644
--- a/sys/kern/kern_mbuf.c
+++ b/sys/kern/kern_mbuf.c
@@ -133,6 +133,7 @@ uma_zone_t	zone_jumbo4;
 uma_zone_t	zone_jumbo9;
 uma_zone_t	zone_jumbo16;
 uma_zone_t	zone_ext_refcnt;
+uma_zone_t	zone_mtag_vlan;
 
 /*
  * Local prototypes.
@@ -145,6 +146,7 @@ static void	mb_dtor_clust(void *, int, void *);
 static void	mb_dtor_pack(void *, int, void *);
 static int	mb_zinit_pack(void *, int, int);
 static void	mb_zfini_pack(void *, int);
+static int	mt_zinit_vlan(void *, int, int);
 
 static void	mb_reclaim(void *);
 static void	mbuf_init(void *);
@@ -225,6 +227,12 @@ mbuf_init(void *dummy)
 	    NULL, NULL,
 	    UMA_ALIGN_PTR, UMA_ZONE_ZINIT);
 
+	zone_mtag_vlan = uma_zcreate("mtag_vlan",
+	    sizeof(struct m_tag) + sizeof(u_int),
+	    NULL, NULL,
+	    mt_zinit_vlan, NULL,
+	    UMA_ALIGN_INT, 0);
+
 	/* uma_prealloc() goes here... */
 
 	/*
@@ -511,6 +519,23 @@ mb_ctor_pack(void *mem, int size, void *arg, int how)
 	return (0);
 }
 
+static void
+mt_vlan_free(struct m_tag *mtag)
+{
+	uma_zfree(zone_mtag_vlan, mtag);
+}
+
+static int
+mt_zinit_vlan(void *mem, int size, int how)
+{
+	struct m_tag *mtag = (struct m_tag *)mem;
+
+	m_tag_setup(mtag, MTAG_VLAN, MTAG_VLAN_TAG, sizeof(u_int));
+	mtag->m_tag_free = mt_vlan_free;
+
+	return (0);
+}
+
 /*
  * This is the protocol drain routine.
  *