Commit cf3637bb authored by Alexander Duyck's avatar Alexander Duyck Committed by David S. Miller

fib_trie: Move resize to after inflate/halve

This change consists of a cut/paste of resize to behind inflate and halve
so that I could remove the two function prototypes.
Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 345e9b54
...@@ -149,8 +149,6 @@ struct trie { ...@@ -149,8 +149,6 @@ struct trie {
static void tnode_put_child_reorg(struct tnode *tn, unsigned long i, static void tnode_put_child_reorg(struct tnode *tn, unsigned long i,
struct tnode *n, int wasfull); struct tnode *n, int wasfull);
static struct tnode *resize(struct trie *t, struct tnode *tn); static struct tnode *resize(struct trie *t, struct tnode *tn);
static struct tnode *inflate(struct trie *t, struct tnode *tn);
static struct tnode *halve(struct trie *t, struct tnode *tn);
/* tnodes to free after resize(); protected by RTNL */ /* tnodes to free after resize(); protected by RTNL */
static struct callback_head *tnode_free_head; static struct callback_head *tnode_free_head;
static size_t tnode_free_size; static size_t tnode_free_size;
...@@ -447,161 +445,6 @@ static void put_child_root(struct tnode *tp, struct trie *t, ...@@ -447,161 +445,6 @@ static void put_child_root(struct tnode *tp, struct trie *t,
rcu_assign_pointer(t->trie, n); rcu_assign_pointer(t->trie, n);
} }
#define MAX_WORK 10
static struct tnode *resize(struct trie *t, struct tnode *tn)
{
struct tnode *old_tn, *n = NULL;
int inflate_threshold_use;
int halve_threshold_use;
int max_work;
if (!tn)
return NULL;
pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
tn, inflate_threshold, halve_threshold);
/* No children */
if (tn->empty_children > (tnode_child_length(tn) - 1))
goto no_children;
/* One child */
if (tn->empty_children == (tnode_child_length(tn) - 1))
goto one_child;
/*
* Double as long as the resulting node has a number of
* nonempty nodes that are above the threshold.
*/
/*
* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
* the Helsinki University of Technology and Matti Tikkanen of Nokia
* Telecommunications, page 6:
* "A node is doubled if the ratio of non-empty children to all
* children in the *doubled* node is at least 'high'."
*
* 'high' in this instance is the variable 'inflate_threshold'. It
* is expressed as a percentage, so we multiply it with
* tnode_child_length() and instead of multiplying by 2 (since the
* child array will be doubled by inflate()) and multiplying
* the left-hand side by 100 (to handle the percentage thing) we
* multiply the left-hand side by 50.
*
* The left-hand side may look a bit weird: tnode_child_length(tn)
* - tn->empty_children is of course the number of non-null children
* in the current node. tn->full_children is the number of "full"
* children, that is non-null tnodes with a skip value of 0.
* All of those will be doubled in the resulting inflated tnode, so
* we just count them one extra time here.
*
* A clearer way to write this would be:
*
* to_be_doubled = tn->full_children;
* not_to_be_doubled = tnode_child_length(tn) - tn->empty_children -
* tn->full_children;
*
* new_child_length = tnode_child_length(tn) * 2;
*
* new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
* new_child_length;
* if (new_fill_factor >= inflate_threshold)
*
* ...and so on, tho it would mess up the while () loop.
*
* anyway,
* 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
* inflate_threshold
*
* avoid a division:
* 100 * (not_to_be_doubled + 2*to_be_doubled) >=
* inflate_threshold * new_child_length
*
* expand not_to_be_doubled and to_be_doubled, and shorten:
* 100 * (tnode_child_length(tn) - tn->empty_children +
* tn->full_children) >= inflate_threshold * new_child_length
*
* expand new_child_length:
* 100 * (tnode_child_length(tn) - tn->empty_children +
* tn->full_children) >=
* inflate_threshold * tnode_child_length(tn) * 2
*
* shorten again:
* 50 * (tn->full_children + tnode_child_length(tn) -
* tn->empty_children) >= inflate_threshold *
* tnode_child_length(tn)
*
*/
/* Keep root node larger */
if (!node_parent(tn)) {
inflate_threshold_use = inflate_threshold_root;
halve_threshold_use = halve_threshold_root;
} else {
inflate_threshold_use = inflate_threshold;
halve_threshold_use = halve_threshold;
}
max_work = MAX_WORK;
while ((tn->full_children > 0 && max_work-- &&
50 * (tn->full_children + tnode_child_length(tn)
- tn->empty_children)
>= inflate_threshold_use * tnode_child_length(tn))) {
old_tn = tn;
tn = inflate(t, tn);
if (IS_ERR(tn)) {
tn = old_tn;
#ifdef CONFIG_IP_FIB_TRIE_STATS
this_cpu_inc(t->stats->resize_node_skipped);
#endif
break;
}
}
/* Return if at least one inflate is run */
if (max_work != MAX_WORK)
return tn;
/*
* Halve as long as the number of empty children in this
* node is above threshold.
*/
max_work = MAX_WORK;
while (tn->bits > 1 && max_work-- &&
100 * (tnode_child_length(tn) - tn->empty_children) <
halve_threshold_use * tnode_child_length(tn)) {
old_tn = tn;
tn = halve(t, tn);
if (IS_ERR(tn)) {
tn = old_tn;
#ifdef CONFIG_IP_FIB_TRIE_STATS
this_cpu_inc(t->stats->resize_node_skipped);
#endif
break;
}
}
/* Only one child remains */
if (tn->empty_children == (tnode_child_length(tn) - 1)) {
unsigned long i;
one_child:
for (i = tnode_child_length(tn); !n && i;)
n = tnode_get_child(tn, --i);
no_children:
/* compress one level */
node_set_parent(n, NULL);
tnode_free_safe(tn);
return n;
}
return tn;
}
static void tnode_clean_free(struct tnode *tn) static void tnode_clean_free(struct tnode *tn)
{ {
struct tnode *tofree; struct tnode *tofree;
...@@ -804,6 +647,160 @@ static struct tnode *halve(struct trie *t, struct tnode *oldtnode) ...@@ -804,6 +647,160 @@ static struct tnode *halve(struct trie *t, struct tnode *oldtnode)
return ERR_PTR(-ENOMEM); return ERR_PTR(-ENOMEM);
} }
#define MAX_WORK 10
static struct tnode *resize(struct trie *t, struct tnode *tn)
{
struct tnode *old_tn, *n = NULL;
int inflate_threshold_use;
int halve_threshold_use;
int max_work;
if (!tn)
return NULL;
pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
tn, inflate_threshold, halve_threshold);
/* No children */
if (tn->empty_children > (tnode_child_length(tn) - 1))
goto no_children;
/* One child */
if (tn->empty_children == (tnode_child_length(tn) - 1))
goto one_child;
/*
* Double as long as the resulting node has a number of
* nonempty nodes that are above the threshold.
*/
/*
* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
* the Helsinki University of Technology and Matti Tikkanen of Nokia
* Telecommunications, page 6:
* "A node is doubled if the ratio of non-empty children to all
* children in the *doubled* node is at least 'high'."
*
* 'high' in this instance is the variable 'inflate_threshold'. It
* is expressed as a percentage, so we multiply it with
* tnode_child_length() and instead of multiplying by 2 (since the
* child array will be doubled by inflate()) and multiplying
* the left-hand side by 100 (to handle the percentage thing) we
* multiply the left-hand side by 50.
*
* The left-hand side may look a bit weird: tnode_child_length(tn)
* - tn->empty_children is of course the number of non-null children
* in the current node. tn->full_children is the number of "full"
* children, that is non-null tnodes with a skip value of 0.
* All of those will be doubled in the resulting inflated tnode, so
* we just count them one extra time here.
*
* A clearer way to write this would be:
*
* to_be_doubled = tn->full_children;
* not_to_be_doubled = tnode_child_length(tn) - tn->empty_children -
* tn->full_children;
*
* new_child_length = tnode_child_length(tn) * 2;
*
* new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
* new_child_length;
* if (new_fill_factor >= inflate_threshold)
*
* ...and so on, tho it would mess up the while () loop.
*
* anyway,
* 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
* inflate_threshold
*
* avoid a division:
* 100 * (not_to_be_doubled + 2*to_be_doubled) >=
* inflate_threshold * new_child_length
*
* expand not_to_be_doubled and to_be_doubled, and shorten:
* 100 * (tnode_child_length(tn) - tn->empty_children +
* tn->full_children) >= inflate_threshold * new_child_length
*
* expand new_child_length:
* 100 * (tnode_child_length(tn) - tn->empty_children +
* tn->full_children) >=
* inflate_threshold * tnode_child_length(tn) * 2
*
* shorten again:
* 50 * (tn->full_children + tnode_child_length(tn) -
* tn->empty_children) >= inflate_threshold *
* tnode_child_length(tn)
*
*/
/* Keep root node larger */
if (!node_parent(tn)) {
inflate_threshold_use = inflate_threshold_root;
halve_threshold_use = halve_threshold_root;
} else {
inflate_threshold_use = inflate_threshold;
halve_threshold_use = halve_threshold;
}
max_work = MAX_WORK;
while ((tn->full_children > 0 && max_work-- &&
50 * (tn->full_children + tnode_child_length(tn)
- tn->empty_children)
>= inflate_threshold_use * tnode_child_length(tn))) {
old_tn = tn;
tn = inflate(t, tn);
if (IS_ERR(tn)) {
tn = old_tn;
#ifdef CONFIG_IP_FIB_TRIE_STATS
this_cpu_inc(t->stats->resize_node_skipped);
#endif
break;
}
}
/* Return if at least one inflate is run */
if (max_work != MAX_WORK)
return tn;
/*
* Halve as long as the number of empty children in this
* node is above threshold.
*/
max_work = MAX_WORK;
while (tn->bits > 1 && max_work-- &&
100 * (tnode_child_length(tn) - tn->empty_children) <
halve_threshold_use * tnode_child_length(tn)) {
old_tn = tn;
tn = halve(t, tn);
if (IS_ERR(tn)) {
tn = old_tn;
#ifdef CONFIG_IP_FIB_TRIE_STATS
this_cpu_inc(t->stats->resize_node_skipped);
#endif
break;
}
}
/* Only one child remains */
if (tn->empty_children == (tnode_child_length(tn) - 1)) {
unsigned long i;
one_child:
for (i = tnode_child_length(tn); !n && i;)
n = tnode_get_child(tn, --i);
no_children:
/* compress one level */
node_set_parent(n, NULL);
tnode_free_safe(tn);
return n;
}
return tn;
}
/* readside must use rcu_read_lock currently dump routines /* readside must use rcu_read_lock currently dump routines
via get_fa_head and dump */ via get_fa_head and dump */
......
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