Stephen Hemminger a écrit :
Combine the prefix information and the leaf together into one
allocation. This is furthur simplified by converting the hlist
into a simple bitfield.

Signed-off-by: Stephen Hemminger <[EMAIL PROTECTED]>

This patch is experimental (ie it boots and loads routes), but
is slower for the 163,000 route dump test.


Its also very memory expensive. That was not Robert suggestion I believe.

Its suggestion is to embedd one info into each leaves.

Please find attached to this mail a preliminary and incomplete patch I wrote this morning before coffee :), to get the idea.

Before patching this file, maybe we should first do a cleanup (checkpatch.pl and obvious modern style formating :) )
---
 net/ipv4/fib_trie.c |  165 ++++++++++++++++++++--------------------------------
 1 file changed, 65 insertions(+), 100 deletions(-)

--- a/net/ipv4/fib_trie.c       2008-01-14 18:37:51.000000000 -0800
+++ b/net/ipv4/fib_trie.c       2008-01-14 20:57:12.000000000 -0800
@@ -50,10 +50,9 @@
  *             Patrick McHardy <[EMAIL PROTECTED]>
  */
-#define VERSION "0.408"
+#define VERSION "0.409"
+
-#include <asm/uaccess.h>
-#include <asm/system.h>
 #include <linux/bitops.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
@@ -80,6 +79,8 @@
 #include <net/tcp.h>
 #include <net/sock.h>
 #include <net/ip_fib.h>
+#include <asm/bitops.h>
+
 #include "fib_lookup.h"
#define MAX_STAT_DEPTH 32
@@ -101,20 +102,24 @@ struct node {
        t_key key;
 };
+struct leaf_info {
+       struct list_head falh;
+};
+
+#define INFO_SIZE      33
+/* NB: bitmap is in reverse order, so that find_first returns largest prefix */
+#define PLEN2BIT(x)    (INFO_SIZE - (x))
+
 struct leaf {
        unsigned long parent;
        t_key key;
-       struct hlist_head list;
        struct rcu_head rcu;
-};
-struct leaf_info {
-       struct hlist_node hlist;
-       struct rcu_head rcu;
-       int plen;
-       struct list_head falh;
+       unsigned long bitmap[INFO_SIZE / BITS_PER_LONG + 1];
+       struct leaf_info info[INFO_SIZE];
 };
+
 struct tnode {
        unsigned long parent;
        t_key key;
@@ -321,16 +326,6 @@ static void __leaf_free_rcu(struct rcu_h
        kmem_cache_free(trie_leaf_kmem, leaf);
 }
-static void __leaf_info_free_rcu(struct rcu_head *head)
-{
-       kfree(container_of(head, struct leaf_info, rcu));
-}
-
-static inline void free_leaf_info(struct leaf_info *leaf)
-{
-       call_rcu(&leaf->rcu, __leaf_info_free_rcu);
-}
-
 static struct tnode *tnode_alloc(size_t size)
 {
        struct page *pages;
@@ -371,21 +366,37 @@ static struct leaf *leaf_new(void)
        struct leaf *l = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
        if (l) {
                l->parent = T_LEAF;
-               INIT_HLIST_HEAD(&l->list);
+               bitmap_zero(l->bitmap, INFO_SIZE);
        }
        return l;
 }
-static struct leaf_info *leaf_info_new(int plen)
+static inline struct leaf_info *find_leaf_info(struct leaf *l, int plen)
 {
-       struct leaf_info *li = kmalloc(sizeof(struct leaf_info),  GFP_KERNEL);
-       if (li) {
-               li->plen = plen;
-               INIT_LIST_HEAD(&li->falh);
-       }
+       return test_bit(PLEN2BIT(plen), l->bitmap) ? &l->info[plen] : NULL;
+}
+
+static struct leaf_info *set_leaf_info(struct leaf *l, int plen)
+{
+       struct leaf_info *li = &l->info[plen];
+
+       INIT_LIST_HEAD(&li->falh);
+       set_bit(PLEN2BIT(plen), l->bitmap);
+
        return li;
 }
+static inline void clear_leaf_info(struct leaf *l, int plen)
+{
+       smp_mb__before_clear_bit();
+       clear_bit(PLEN2BIT(plen), &l->bitmap);
+}
+
+static inline int leaf_info_empty(const struct leaf *l)
+{
+       return find_first_bit(l->bitmap, INFO_SIZE) >= INFO_SIZE;
+}
+
 static struct tnode* tnode_new(t_key key, int pos, int bits)
 {
        size_t sz = sizeof(struct tnode) + (sizeof(struct node *) << bits);
@@ -876,20 +887,6 @@ nomem:
/* readside must use rcu_read_lock currently dump routines
  via get_fa_head and dump */
-
-static struct leaf_info *find_leaf_info(struct leaf *l, int plen)
-{
-       struct hlist_head *head = &l->list;
-       struct hlist_node *node;
-       struct leaf_info *li;
-
-       hlist_for_each_entry_rcu(li, node, head, hlist)
-               if (li->plen == plen)
-                       return li;
-
-       return NULL;
-}
-
 static inline struct list_head * get_fa_head(struct leaf *l, int plen)
 {
        struct leaf_info *li = find_leaf_info(l, plen);
@@ -900,26 +897,6 @@ static inline struct list_head * get_fa_
        return &li->falh;
 }
-static void insert_leaf_info(struct hlist_head *head, struct leaf_info *new)
-{
-       struct leaf_info *li = NULL, *last = NULL;
-       struct hlist_node *node;
-
-       if (hlist_empty(head)) {
-               hlist_add_head_rcu(&new->hlist, head);
-       } else {
-               hlist_for_each_entry(li, node, head, hlist) {
-                       if (new->plen > li->plen)
-                               break;
-
-                       last = li;
-               }
-               if (last)
-                       hlist_add_after_rcu(&last->hlist, &new->hlist);
-               else
-                       hlist_add_before_rcu(&new->hlist, &li->hlist);
-       }
-}
/* rcu_read_lock needs to be hold by caller from readside */ @@ -993,6 +970,8 @@ static struct list_head *fib_insert_node
        pos = 0;
        n = t->trie;
+ pr_debug("fib_insert_node: %x/%d\n", key, plen);
+
        /* If we point to NULL, stop. Either the tree is empty and we should
         * just put a new leaf in if, or we have reached an empty child slot,
         * and we should just put our new leaf in that.
@@ -1038,13 +1017,9 @@ static struct list_head *fib_insert_node
if (n != NULL && IS_LEAF(n) && tkey_equals(key, n->key)) {
                l = (struct leaf *) n;
-               li = leaf_info_new(plen);
-
-               if (!li)
-                       return NULL;
-
+               li = set_leaf_info(l, plen);
                fa_head = &li->falh;
-               insert_leaf_info(&l->list, li);
+
                goto done;
        }
        l = leaf_new();
@@ -1053,15 +1028,8 @@ static struct list_head *fib_insert_node
                return NULL;
l->key = key;
-       li = leaf_info_new(plen);
-
-       if (!li) {
-               tnode_free((struct tnode *) l);
-               return NULL;
-       }
-
+       li = set_leaf_info(l, plen);
        fa_head = &li->falh;
-       insert_leaf_info(&l->list, li);
if (t->trie && n == NULL) {
                /* Case 2: n is NULL, and will just insert a new leaf */
@@ -1091,7 +1059,6 @@ static struct list_head *fib_insert_node
                }
if (!tn) {
-                       free_leaf_info(li);
                        tnode_free((struct tnode *) l);
                        return NULL;
                }
@@ -1119,7 +1086,7 @@ static struct list_head *fib_insert_node
rcu_assign_pointer(t->trie, trie_rebalance(t, tp));
 done:
-       return fa_head;
+       return &li->falh;
 }
/*
@@ -1281,14 +1248,14 @@ static int check_leaf(struct trie *t, st
                      t_key key,  const struct flowi *flp,
                      struct fib_result *res)
 {
-       struct leaf_info *li;
-       struct hlist_head *hhead = &l->list;
-       struct hlist_node *node;
+       int bit;
- hlist_for_each_entry_rcu(li, node, hhead, hlist) {
-               int err;
-               int plen = li->plen;
+       /* need find highest prefix */
+       for_each_bit(bit, l->bitmap, INFO_SIZE) {
+               int plen = PLEN2BIT(bit);
+               struct leaf_info *li = &l->info[plen];
                __be32 mask = inet_make_mask(plen);
+               int err;
if (l->key != (key & ntohl(mask)))
                        continue;
@@ -1622,12 +1589,10 @@ static int fn_trie_delete(struct fib_tab
list_del_rcu(&fa->fa_list); - if (list_empty(fa_head)) {
-               hlist_del_rcu(&li->hlist);
-               free_leaf_info(li);
-       }
+       if (list_empty(fa_head))
+               clear_leaf_info(l, plen);
- if (hlist_empty(&l->list))
+       if (leaf_info_empty(l))
                trie_leaf_remove(t, key);
if (fa->fa_state & FA_S_ACCESSED)
@@ -1659,18 +1624,17 @@ static int trie_flush_list(struct trie *
 static int trie_flush_leaf(struct trie *t, struct leaf *l)
 {
        int found = 0;
-       struct hlist_head *lih = &l->list;
-       struct hlist_node *node, *tmp;
-       struct leaf_info *li = NULL;
+       int bit;
- hlist_for_each_entry_safe(li, node, tmp, lih, hlist) {
+       for_each_bit(bit, l->bitmap, INFO_SIZE) {
+               int plen = PLEN2BIT(bit);
+               struct leaf_info *li = &l->info[plen];
                found += trie_flush_list(t, &li->falh);
- if (list_empty(&li->falh)) {
-                       hlist_del_rcu(&li->hlist);
-                       free_leaf_info(li);
-               }
+               if (list_empty(&li->falh))
+                       clear_leaf_info(l, plen);
        }
+
        return found;
 }
@@ -1746,12 +1710,12 @@ static int fn_trie_flush(struct fib_tabl
        for (h = 0; (l = nextleaf(t, l)) != NULL; h++) {
                found += trie_flush_leaf(t, l);
- if (ll && hlist_empty(&ll->list))
+               if (ll && leaf_info_empty(ll))
                        trie_leaf_remove(t, ll->key);
                ll = l;
        }
- if (ll && hlist_empty(&ll->list))
+       if (ll && leaf_info_empty(ll))
                trie_leaf_remove(t, ll->key);
pr_debug("trie_flush found=%d\n", found);
@@ -2428,10 +2392,11 @@ static int fib_route_seq_show(struct seq
if (iter->trie == iter->trie_local)
                return 0;
+
        if (IS_TNODE(l))
                return 0;
- for (i=32; i>=0; i--) {
+       for (i = 32; i >= 0; i--) {
                struct leaf_info *li = find_leaf_info(l, i);
                struct fib_alias *fa;
                __be32 mask, prefix;
@@ -2439,7 +2404,7 @@ static int fib_route_seq_show(struct seq
                if (!li)
                        continue;
- mask = inet_make_mask(li->plen);
+               mask = inet_make_mask(i);
                prefix = htonl(l->key);
list_for_each_entry_rcu(fa, &li->falh, fa_list) {
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html



--- net/ipv4/fib_trie.c
+++ net/ipv4/fib_trie.c.rcu
@@ -97,30 +97,22 @@
 #define IS_LEAF(n) (n->parent & T_LEAF)
 
 struct node {
-       unsigned long           parent;
-       t_key                   key;
+       unsigned long parent;
+       t_key key;
 };
 
 struct leaf {
-       unsigned long           parent;
-       t_key                   key;
-       /*
-        * Because we have at least one info per leaf, we embedd one here
-        * to save some space and speedup lookups (sharing cache line)
-        * Note : not inside a structure so that we dont have holes on 64bit 
-        */
-       int                     plen_iinfo;
-       struct list_head        falh_iinfo;
-
-       struct hlist_head       list;
-       struct rcu_head         rcu;
+       unsigned long parent;
+       t_key key;
+       struct hlist_head list;
+       struct rcu_head rcu;
 };
 
 struct leaf_info {
-       struct hlist_node       hlist;
-       int                     plen;
-       struct list_head        falh;
-       struct rcu_head         rcu;
+       struct hlist_node hlist;
+       struct rcu_head rcu;
+       int plen;
+       struct list_head falh;
 };
 
 struct tnode {
@@ -381,13 +373,11 @@
                call_rcu(&tn->rcu, __tnode_free_rcu);
 }
 
-static struct leaf *leaf_new(int plen)
+static struct leaf *leaf_new(void)
 {
        struct leaf *l = kmalloc(sizeof(struct leaf),  GFP_KERNEL);
        if (l) {
                l->parent = T_LEAF;
-               l->plen_iinfo = plen;
-               INIT_LIST_HEAD(&l->falh_iinfo);
                INIT_HLIST_HEAD(&l->list);
        }
        return l;
@@ -909,12 +899,7 @@
 
 static inline struct list_head * get_fa_head(struct leaf *l, int plen)
 {
-       struct leaf_info *li;
-
-       if (plen == l->plen_iinfo)
-               return &l->falh_iinfo;
-
-       li = find_leaf_info(l, plen);
+       struct leaf_info *li = find_leaf_info(l, plen);
 
        if (!li)
                return NULL;
@@ -1071,22 +1056,21 @@
                goto done;
        }
        t->size++;
-       l = leaf_new(plen);
+       l = leaf_new();
 
        if (!l)
                return NULL;
 
        l->key = key;
-//     li = leaf_info_new(plen);
+       li = leaf_info_new(plen);
+
+       if (!li) {
+               tnode_free((struct tnode *) l);
+               return NULL;
+       }
 
-//     if (!li) {
-//             tnode_free((struct tnode *) l);
-//             return NULL;
-//     }
-
-//     fa_head = &li->falh;
-//     insert_leaf_info(&l->list, li);
-       fa_head = &l->falh_iinfo;
+       fa_head = &li->falh;
+       insert_leaf_info(&l->list, li);
 
        if (t->trie && n == NULL) {
                /* Case 2: n is NULL, and will just insert a new leaf */
@@ -1116,7 +1100,7 @@
                }
 
                if (!tn) {
-//                     free_leaf_info(li);
+                       free_leaf_info(li);
                        tnode_free((struct tnode *) l);
                        return NULL;
                }
@@ -1640,7 +1624,7 @@
        li = find_leaf_info(l, plen);
 
        list_del_rcu(&fa->fa_list);
-// FIXME
+
        if (list_empty(fa_head)) {
                hlist_del_rcu(&li->hlist);
                free_leaf_info(li);
@@ -2382,11 +2366,10 @@
                seq_indent(seq, iter->depth);
                seq_printf(seq, "  |-- %d.%d.%d.%d\n", NIPQUAD(val));
                for (i = 32; i >= 0; i--) {
-//                     struct leaf_info *li = get_fa_head(l, i); 
//find_leaf_info(l, i);
-                       struct list_head *fa_head = get_fa_head(l, i);
-                       if (fa_head) {
+                       struct leaf_info *li = find_leaf_info(l, i);
+                       if (li) {
                                struct fib_alias *fa;
-                               list_for_each_entry_rcu(fa, fa_head, fa_list) {
+                               list_for_each_entry_rcu(fa, &li->falh, fa_list) 
{
                                        seq_indent(seq, iter->depth+1);
                                        seq_printf(seq, "  /%d %s %s", i,
                                                   rtn_scope(fa->fa_scope),
@@ -2465,18 +2448,17 @@
                return 0;
 
        for (i=32; i>=0; i--) {
-               //struct leaf_info *li = find_leaf_info(l, i);
-               struct list_head *fa_head = get_fa_head(l, i);
+               struct leaf_info *li = find_leaf_info(l, i);
                struct fib_alias *fa;
                __be32 mask, prefix;
 
-               if (!fa_head)
+               if (!li)
                        continue;
 
-               mask = inet_make_mask(i);
+               mask = inet_make_mask(li->plen);
                prefix = htonl(l->key);
 
-               list_for_each_entry_rcu(fa, fa_head, fa_list) {
+               list_for_each_entry_rcu(fa, &li->falh, fa_list) {
                        const struct fib_info *fi = fa->fa_info;
                        unsigned flags = fib_flag_trans(fa->fa_type, mask, fi);
 

Reply via email to