classify: use 32 bits hash
classify hash used to be stored as u64 in buffer metadata, use 32 bits
instead:
- on almost all our supported arch (x86 and arm64) we use crc32c
intrinsics to compute the final hash: we really get a 32-bits hash
- the hash itself is used to compute a 32-bits bucket index by masking
upper bits: we always discard the higher 32-bits
- this allows to increase the l2 classify buffer metadata padding such
as it does not overlap with the ip fib_index metadata anymore. This
overlap is an issue when using the 'set metadata' action in the ip
ACL node which updates both fields
Type: fix
Change-Id: I5d35bdae97b96c3cae534e859b63950fb500ff50
Signed-off-by: Benoît Ganne <bganne@cisco.com>
diff --git a/src/vnet/classify/vnet_classify.c b/src/vnet/classify/vnet_classify.c
index 479d302..8281be5 100644
--- a/src/vnet/classify/vnet_classify.c
+++ b/src/vnet/classify/vnet_classify.c
@@ -424,7 +424,7 @@
u32 value_index;
int rv = 0;
int i;
- u64 hash, new_hash;
+ u32 hash, new_hash;
u32 limit;
u32 old_log2_pages, new_log2_pages;
u32 thread_index = vlib_get_thread_index ();
@@ -647,15 +647,15 @@
}) classify_data_or_mask_t;
/* *INDENT-ON* */
-u64
-vnet_classify_hash_packet (vnet_classify_table_t * t, u8 * h)
+u32
+vnet_classify_hash_packet (const vnet_classify_table_t *t, u8 *h)
{
return vnet_classify_hash_packet_inline (t, h);
}
vnet_classify_entry_t *
-vnet_classify_find_entry (vnet_classify_table_t * t,
- u8 * h, u64 hash, f64 now)
+vnet_classify_find_entry (const vnet_classify_table_t *t, u8 *h, u32 hash,
+ f64 now)
{
return vnet_classify_find_entry_inline (t, h, hash, now);
}
@@ -3235,7 +3235,7 @@
for (i = 0; i < tm->sessions; i++)
{
u8 *key_minus_skip;
- u64 hash;
+ u32 hash;
vnet_classify_entry_t *e;
ep = tm->entries + i;