Commit 7eb60345 authored by David S. Miller's avatar David S. Miller

Merge branch 'fib_trie_remove_leaf_info'

Alexander Duyck says:

====================
fib_trie: Remove leaf_info structure

This patch set removes the leaf_info structure from the IPv4 fib_trie.  The
general idea is that the leaf_info structure itself only held about 6
actual bits of data, beyond that it was mostly just waste.  As such we can
drop the structure, move the 1 byte representing the prefix/suffix length
into the fib_alias and just link it all into one list.

My testing shows that this saves somewhere between 4 to 10ns depending on
the type of test performed.  I'm suspecting that this represents 1 to 2 L1
cache misses saved per look-up.

One side effect of this change is that semantic_match_miss will now only
increment once per leaf instead of once per leaf_info miss.  However the
stat is already skewed now that we perform a preliminary check on the leaf
as a part of the look-up.

I also have gone through and addressed a number of ordering issues in the
first patch since I had misread the behavior of list_add_tail.

I have since run some additional testing and verified the resulting lists
are in the same order when combining multiple prefix length and tos values
in a single leaf.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 7705f730 79e5ad2c
...@@ -136,7 +136,7 @@ struct fib_result { ...@@ -136,7 +136,7 @@ struct fib_result {
u32 tclassid; u32 tclassid;
struct fib_info *fi; struct fib_info *fi;
struct fib_table *table; struct fib_table *table;
struct list_head *fa_head; struct hlist_head *fa_head;
}; };
struct fib_result_nl { struct fib_result_nl {
......
...@@ -6,11 +6,12 @@ ...@@ -6,11 +6,12 @@
#include <net/ip_fib.h> #include <net/ip_fib.h>
struct fib_alias { struct fib_alias {
struct list_head fa_list; struct hlist_node fa_list;
struct fib_info *fa_info; struct fib_info *fa_info;
u8 fa_tos; u8 fa_tos;
u8 fa_type; u8 fa_type;
u8 fa_state; u8 fa_state;
u8 fa_slen;
struct rcu_head rcu; struct rcu_head rcu;
}; };
......
...@@ -1163,12 +1163,12 @@ int fib_sync_down_dev(struct net_device *dev, int force) ...@@ -1163,12 +1163,12 @@ int fib_sync_down_dev(struct net_device *dev, int force)
void fib_select_default(struct fib_result *res) void fib_select_default(struct fib_result *res)
{ {
struct fib_info *fi = NULL, *last_resort = NULL; struct fib_info *fi = NULL, *last_resort = NULL;
struct list_head *fa_head = res->fa_head; struct hlist_head *fa_head = res->fa_head;
struct fib_table *tb = res->table; struct fib_table *tb = res->table;
int order = -1, last_idx = -1; int order = -1, last_idx = -1;
struct fib_alias *fa; struct fib_alias *fa;
list_for_each_entry_rcu(fa, fa_head, fa_list) { hlist_for_each_entry_rcu(fa, fa_head, fa_list) {
struct fib_info *next_fi = fa->fa_info; struct fib_info *next_fi = fa->fa_info;
if (next_fi->fib_scope != res->scope || if (next_fi->fib_scope != res->scope ||
......
This diff is collapsed.
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment