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authorNeale Ranns <nranns@cisco.com>2017-03-23 06:46:01 -0700
committerDamjan Marion <dmarion.lists@gmail.com>2017-03-29 13:00:52 +0000
commit04a75e3230ab71248fc29a56b9f64bdaee0c17ac (patch)
tree85977ecfdf1c4002451cbbcf075694ae1ba1173c /src/vnet/ip/ip4_mtrie.h
parent9a69a6095f67b8979a02f128f44e449889454273 (diff)
Mtrie optimisations
1 - make the default route non-special, i.e. like any other less specific route. Consequently, all buckets have a valid valid index of either a leaf or a ply. Checks for special indeices in the data-path can thus be removed. 2 - since all leaves are now 'real' i.e. they represent a real load-balance object, to tell if a ply slot is 'empty' requeirs chekcing that the prefix length of the leaf occupying the slot is slot than the minium value for that ply. 3 - when removing a leaf find the cover first, then recurse down the ply and replace the old leaf with the cover. This saves us a ply walk. Change-Id: Idd523019e8bb1b6ef527b1f5279a5e24bcf18332 Signed-off-by: Neale Ranns <nranns@cisco.com>
Diffstat (limited to 'src/vnet/ip/ip4_mtrie.h')
-rw-r--r--src/vnet/ip/ip4_mtrie.h125
1 files changed, 53 insertions, 72 deletions
diff --git a/src/vnet/ip/ip4_mtrie.h b/src/vnet/ip/ip4_mtrie.h
index c0afc2cf842..128195d3a52 100644
--- a/src/vnet/ip/ip4_mtrie.h
+++ b/src/vnet/ip/ip4_mtrie.h
@@ -52,67 +52,15 @@
typedef u32 ip4_fib_mtrie_leaf_t;
#define IP4_FIB_MTRIE_LEAF_EMPTY (1 + 2*0)
-#define IP4_FIB_MTRIE_LEAF_ROOT (0 + 2*0)
-always_inline u32
-ip4_fib_mtrie_leaf_is_empty (ip4_fib_mtrie_leaf_t n)
-{
- return n == IP4_FIB_MTRIE_LEAF_EMPTY;
-}
-
-always_inline u32
-ip4_fib_mtrie_leaf_is_non_empty (ip4_fib_mtrie_leaf_t n)
-{
- return n != IP4_FIB_MTRIE_LEAF_EMPTY;
-}
-
-always_inline u32
-ip4_fib_mtrie_leaf_is_terminal (ip4_fib_mtrie_leaf_t n)
-{
- return n & 1;
-}
-
-always_inline u32
-ip4_fib_mtrie_leaf_get_adj_index (ip4_fib_mtrie_leaf_t n)
-{
- ASSERT (ip4_fib_mtrie_leaf_is_terminal (n));
- return n >> 1;
-}
-
-always_inline ip4_fib_mtrie_leaf_t
-ip4_fib_mtrie_leaf_set_adj_index (u32 adj_index)
-{
- ip4_fib_mtrie_leaf_t l;
- l = 1 + 2 * adj_index;
- ASSERT (ip4_fib_mtrie_leaf_get_adj_index (l) == adj_index);
- return l;
-}
-
-always_inline u32
-ip4_fib_mtrie_leaf_is_next_ply (ip4_fib_mtrie_leaf_t n)
-{
- return (n & 1) == 0;
-}
-
-always_inline u32
-ip4_fib_mtrie_leaf_get_next_ply_index (ip4_fib_mtrie_leaf_t n)
-{
- ASSERT (ip4_fib_mtrie_leaf_is_next_ply (n));
- return n >> 1;
-}
-
-always_inline ip4_fib_mtrie_leaf_t
-ip4_fib_mtrie_leaf_set_next_ply_index (u32 i)
-{
- ip4_fib_mtrie_leaf_t l;
- l = 0 + 2 * i;
- ASSERT (ip4_fib_mtrie_leaf_get_next_ply_index (l) == i);
- return l;
-}
-
-/* One ply of the 4 ply mtrie fib. */
+/**
+ * @brief One ply of the 4 ply mtrie fib.
+ */
typedef struct
{
+ /**
+ * The leaves/slots/buckets to be filed with leafs
+ */
union
{
ip4_fib_mtrie_leaf_t leaves[256];
@@ -122,14 +70,25 @@ typedef struct
#endif
};
- /* Prefix length for terminal leaves. */
+ /**
+ * Prefix length for leaves/ply.
+ */
u8 dst_address_bits_of_leaves[256];
- /* Number of non-empty leafs (whether terminal or not). */
+ /**
+ * Number of non-empty leafs (whether terminal or not).
+ */
i32 n_non_empty_leafs;
+ /**
+ * The length of the ply's coviering prefix. Also a measure of its depth
+ * If a leaf in a slot has a mask length longer than this then it is
+ * 'non-empty'. Otherwise it is the value of the cover.
+ */
+ i32 dst_address_bits_base;
+
/* Pad to cache line boundary. */
- u8 pad[CLIB_CACHE_LINE_BYTES - 1 * sizeof (i32)];
+ u8 pad[CLIB_CACHE_LINE_BYTES - 2 * sizeof (i32)];
}
ip4_fib_mtrie_ply_t;
@@ -140,9 +99,6 @@ typedef struct
{
/* Pool of plies. Index zero is root ply. */
ip4_fib_mtrie_ply_t *ply_pool;
-
- /* Special case leaf for default route 0.0.0.0/0. */
- ip4_fib_mtrie_leaf_t default_leaf;
} ip4_fib_mtrie_t;
void ip4_fib_mtrie_init (ip4_fib_mtrie_t * m);
@@ -154,25 +110,50 @@ void ip4_fib_mtrie_add_del_route (struct ip4_fib_t *f,
u32 dst_address_length,
u32 adj_index, u32 is_del);
-/* Returns adjacency index. */
-u32 ip4_mtrie_lookup_address (ip4_fib_mtrie_t * m, ip4_address_t dst);
-
format_function_t format_ip4_fib_mtrie;
+always_inline u32
+ip4_fib_mtrie_leaf_is_terminal (ip4_fib_mtrie_leaf_t n)
+{
+ return n & 1;
+}
+
+always_inline u32
+ip4_fib_mtrie_leaf_get_adj_index (ip4_fib_mtrie_leaf_t n)
+{
+ ASSERT (ip4_fib_mtrie_leaf_is_terminal (n));
+ return n >> 1;
+}
+
/* Lookup step. Processes 1 byte of 4 byte ip4 address. */
always_inline ip4_fib_mtrie_leaf_t
-ip4_fib_mtrie_lookup_step (ip4_fib_mtrie_t * m,
+ip4_fib_mtrie_lookup_step (const ip4_fib_mtrie_t * m,
ip4_fib_mtrie_leaf_t current_leaf,
const ip4_address_t * dst_address,
u32 dst_address_byte_index)
{
- ip4_fib_mtrie_leaf_t next_leaf;
ip4_fib_mtrie_ply_t *ply;
uword current_is_terminal = ip4_fib_mtrie_leaf_is_terminal (current_leaf);
- ply = m->ply_pool + (current_is_terminal ? 0 : (current_leaf >> 1));
- next_leaf = ply->leaves[dst_address->as_u8[dst_address_byte_index]];
- next_leaf = current_is_terminal ? current_leaf : next_leaf;
+ if (!current_is_terminal)
+ {
+ ply = m->ply_pool + (current_leaf >> 1);
+ return (ply->leaves[dst_address->as_u8[dst_address_byte_index]]);
+ }
+
+ return current_leaf;
+}
+
+/* Lookup step. Processes 1 byte of 4 byte ip4 address. */
+always_inline ip4_fib_mtrie_leaf_t
+ip4_fib_mtrie_lookup_step_one (const ip4_fib_mtrie_t * m,
+ const ip4_address_t * dst_address)
+{
+ ip4_fib_mtrie_leaf_t next_leaf;
+ ip4_fib_mtrie_ply_t *ply;
+
+ ply = m->ply_pool;
+ next_leaf = ply->leaves[dst_address->as_u8[0]];
return next_leaf;
}