From 01573e231f18eb2d99162747186f59511f56b64d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 08 Dec 2023 10:40:48 +0000
Subject: [PATCH] 移去rt
---
kernel/net/openvswitch/flow_table.c | 783 +++++++++++++++++++++++++++++++++++++++++++------------
1 files changed, 614 insertions(+), 169 deletions(-)
diff --git a/kernel/net/openvswitch/flow_table.c b/kernel/net/openvswitch/flow_table.c
index 80ea2a7..c89c8da 100644
--- a/kernel/net/openvswitch/flow_table.c
+++ b/kernel/net/openvswitch/flow_table.c
@@ -1,19 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2007-2014 Nicira, Inc.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but
- * WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
- * 02110-1301, USA
*/
#include "flow.h"
@@ -42,12 +29,18 @@
#include <linux/icmp.h>
#include <linux/icmpv6.h>
#include <linux/rculist.h>
+#include <linux/sort.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/ndisc.h>
#define TBL_MIN_BUCKETS 1024
+#define MASK_ARRAY_SIZE_MIN 16
#define REHASH_INTERVAL (10 * 60 * HZ)
+
+#define MC_DEFAULT_HASH_ENTRIES 256
+#define MC_HASH_SHIFT 8
+#define MC_HASH_SEGS ((sizeof(uint32_t) * 8) / MC_HASH_SHIFT)
static struct kmem_cache *flow_cache;
struct kmem_cache *flow_stats_cache __read_mostly;
@@ -79,7 +72,7 @@
struct sw_flow *ovs_flow_alloc(void)
{
struct sw_flow *flow;
- struct flow_stats *stats;
+ struct sw_flow_stats *stats;
flow = kmem_cache_zalloc(flow_cache, GFP_KERNEL);
if (!flow)
@@ -111,29 +104,6 @@
return table->count;
}
-static struct flex_array *alloc_buckets(unsigned int n_buckets)
-{
- struct flex_array *buckets;
- int i, err;
-
- buckets = flex_array_alloc(sizeof(struct hlist_head),
- n_buckets, GFP_KERNEL);
- if (!buckets)
- return NULL;
-
- err = flex_array_prealloc(buckets, 0, n_buckets, GFP_KERNEL);
- if (err) {
- flex_array_free(buckets);
- return NULL;
- }
-
- for (i = 0; i < n_buckets; i++)
- INIT_HLIST_HEAD((struct hlist_head *)
- flex_array_get(buckets, i));
-
- return buckets;
-}
-
static void flow_free(struct sw_flow *flow)
{
int cpu;
@@ -141,12 +111,16 @@
if (ovs_identifier_is_key(&flow->id))
kfree(flow->id.unmasked_key);
if (flow->sf_acts)
- ovs_nla_free_flow_actions((struct sw_flow_actions __force *)flow->sf_acts);
+ ovs_nla_free_flow_actions((struct sw_flow_actions __force *)
+ flow->sf_acts);
/* We open code this to make sure cpu 0 is always considered */
- for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask))
+ for (cpu = 0; cpu < nr_cpu_ids;
+ cpu = cpumask_next(cpu, &flow->cpu_used_mask)) {
if (flow->stats[cpu])
kmem_cache_free(flow_stats_cache,
- (struct flow_stats __force *)flow->stats[cpu]);
+ (struct sw_flow_stats __force *)flow->stats[cpu]);
+ }
+
kmem_cache_free(flow_cache, flow);
}
@@ -168,47 +142,291 @@
flow_free(flow);
}
-static void free_buckets(struct flex_array *buckets)
-{
- flex_array_free(buckets);
-}
-
-
static void __table_instance_destroy(struct table_instance *ti)
{
- free_buckets(ti->buckets);
+ kvfree(ti->buckets);
kfree(ti);
}
static struct table_instance *table_instance_alloc(int new_size)
{
struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
+ int i;
if (!ti)
return NULL;
- ti->buckets = alloc_buckets(new_size);
-
+ ti->buckets = kvmalloc_array(new_size, sizeof(struct hlist_head),
+ GFP_KERNEL);
if (!ti->buckets) {
kfree(ti);
return NULL;
}
+
+ for (i = 0; i < new_size; i++)
+ INIT_HLIST_HEAD(&ti->buckets[i]);
+
ti->n_buckets = new_size;
ti->node_ver = 0;
- ti->keep_flows = false;
get_random_bytes(&ti->hash_seed, sizeof(u32));
return ti;
}
+static void __mask_array_destroy(struct mask_array *ma)
+{
+ free_percpu(ma->masks_usage_stats);
+ kfree(ma);
+}
+
+static void mask_array_rcu_cb(struct rcu_head *rcu)
+{
+ struct mask_array *ma = container_of(rcu, struct mask_array, rcu);
+
+ __mask_array_destroy(ma);
+}
+
+static void tbl_mask_array_reset_counters(struct mask_array *ma)
+{
+ int i, cpu;
+
+ /* As the per CPU counters are not atomic we can not go ahead and
+ * reset them from another CPU. To be able to still have an approximate
+ * zero based counter we store the value at reset, and subtract it
+ * later when processing.
+ */
+ for (i = 0; i < ma->max; i++) {
+ ma->masks_usage_zero_cntr[i] = 0;
+
+ for_each_possible_cpu(cpu) {
+ struct mask_array_stats *stats;
+ unsigned int start;
+ u64 counter;
+
+ stats = per_cpu_ptr(ma->masks_usage_stats, cpu);
+ do {
+ start = u64_stats_fetch_begin_irq(&stats->syncp);
+ counter = stats->usage_cntrs[i];
+ } while (u64_stats_fetch_retry_irq(&stats->syncp, start));
+
+ ma->masks_usage_zero_cntr[i] += counter;
+ }
+ }
+}
+
+static struct mask_array *tbl_mask_array_alloc(int size)
+{
+ struct mask_array *new;
+
+ size = max(MASK_ARRAY_SIZE_MIN, size);
+ new = kzalloc(sizeof(struct mask_array) +
+ sizeof(struct sw_flow_mask *) * size +
+ sizeof(u64) * size, GFP_KERNEL);
+ if (!new)
+ return NULL;
+
+ new->masks_usage_zero_cntr = (u64 *)((u8 *)new +
+ sizeof(struct mask_array) +
+ sizeof(struct sw_flow_mask *) *
+ size);
+
+ new->masks_usage_stats = __alloc_percpu(sizeof(struct mask_array_stats) +
+ sizeof(u64) * size,
+ __alignof__(u64));
+ if (!new->masks_usage_stats) {
+ kfree(new);
+ return NULL;
+ }
+
+ new->count = 0;
+ new->max = size;
+
+ return new;
+}
+
+static int tbl_mask_array_realloc(struct flow_table *tbl, int size)
+{
+ struct mask_array *old;
+ struct mask_array *new;
+
+ new = tbl_mask_array_alloc(size);
+ if (!new)
+ return -ENOMEM;
+
+ old = ovsl_dereference(tbl->mask_array);
+ if (old) {
+ int i;
+
+ for (i = 0; i < old->max; i++) {
+ if (ovsl_dereference(old->masks[i]))
+ new->masks[new->count++] = old->masks[i];
+ }
+ call_rcu(&old->rcu, mask_array_rcu_cb);
+ }
+
+ rcu_assign_pointer(tbl->mask_array, new);
+
+ return 0;
+}
+
+static int tbl_mask_array_add_mask(struct flow_table *tbl,
+ struct sw_flow_mask *new)
+{
+ struct mask_array *ma = ovsl_dereference(tbl->mask_array);
+ int err, ma_count = READ_ONCE(ma->count);
+
+ if (ma_count >= ma->max) {
+ err = tbl_mask_array_realloc(tbl, ma->max +
+ MASK_ARRAY_SIZE_MIN);
+ if (err)
+ return err;
+
+ ma = ovsl_dereference(tbl->mask_array);
+ } else {
+ /* On every add or delete we need to reset the counters so
+ * every new mask gets a fair chance of being prioritized.
+ */
+ tbl_mask_array_reset_counters(ma);
+ }
+
+ BUG_ON(ovsl_dereference(ma->masks[ma_count]));
+
+ rcu_assign_pointer(ma->masks[ma_count], new);
+ WRITE_ONCE(ma->count, ma_count + 1);
+
+ return 0;
+}
+
+static void tbl_mask_array_del_mask(struct flow_table *tbl,
+ struct sw_flow_mask *mask)
+{
+ struct mask_array *ma = ovsl_dereference(tbl->mask_array);
+ int i, ma_count = READ_ONCE(ma->count);
+
+ /* Remove the deleted mask pointers from the array */
+ for (i = 0; i < ma_count; i++) {
+ if (mask == ovsl_dereference(ma->masks[i]))
+ goto found;
+ }
+
+ BUG();
+ return;
+
+found:
+ WRITE_ONCE(ma->count, ma_count - 1);
+
+ rcu_assign_pointer(ma->masks[i], ma->masks[ma_count - 1]);
+ RCU_INIT_POINTER(ma->masks[ma_count - 1], NULL);
+
+ kfree_rcu(mask, rcu);
+
+ /* Shrink the mask array if necessary. */
+ if (ma->max >= (MASK_ARRAY_SIZE_MIN * 2) &&
+ ma_count <= (ma->max / 3))
+ tbl_mask_array_realloc(tbl, ma->max / 2);
+ else
+ tbl_mask_array_reset_counters(ma);
+
+}
+
+/* Remove 'mask' from the mask list, if it is not needed any more. */
+static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask)
+{
+ if (mask) {
+ /* ovs-lock is required to protect mask-refcount and
+ * mask list.
+ */
+ ASSERT_OVSL();
+ BUG_ON(!mask->ref_count);
+ mask->ref_count--;
+
+ if (!mask->ref_count)
+ tbl_mask_array_del_mask(tbl, mask);
+ }
+}
+
+static void __mask_cache_destroy(struct mask_cache *mc)
+{
+ free_percpu(mc->mask_cache);
+ kfree(mc);
+}
+
+static void mask_cache_rcu_cb(struct rcu_head *rcu)
+{
+ struct mask_cache *mc = container_of(rcu, struct mask_cache, rcu);
+
+ __mask_cache_destroy(mc);
+}
+
+static struct mask_cache *tbl_mask_cache_alloc(u32 size)
+{
+ struct mask_cache_entry __percpu *cache = NULL;
+ struct mask_cache *new;
+
+ /* Only allow size to be 0, or a power of 2, and does not exceed
+ * percpu allocation size.
+ */
+ if ((!is_power_of_2(size) && size != 0) ||
+ (size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE)
+ return NULL;
+
+ new = kzalloc(sizeof(*new), GFP_KERNEL);
+ if (!new)
+ return NULL;
+
+ new->cache_size = size;
+ if (new->cache_size > 0) {
+ cache = __alloc_percpu(array_size(sizeof(struct mask_cache_entry),
+ new->cache_size),
+ __alignof__(struct mask_cache_entry));
+ if (!cache) {
+ kfree(new);
+ return NULL;
+ }
+ }
+
+ new->mask_cache = cache;
+ return new;
+}
+int ovs_flow_tbl_masks_cache_resize(struct flow_table *table, u32 size)
+{
+ struct mask_cache *mc = rcu_dereference_ovsl(table->mask_cache);
+ struct mask_cache *new;
+
+ if (size == mc->cache_size)
+ return 0;
+
+ if ((!is_power_of_2(size) && size != 0) ||
+ (size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE)
+ return -EINVAL;
+
+ new = tbl_mask_cache_alloc(size);
+ if (!new)
+ return -ENOMEM;
+
+ rcu_assign_pointer(table->mask_cache, new);
+ call_rcu(&mc->rcu, mask_cache_rcu_cb);
+
+ return 0;
+}
+
int ovs_flow_tbl_init(struct flow_table *table)
{
struct table_instance *ti, *ufid_ti;
+ struct mask_cache *mc;
+ struct mask_array *ma;
+
+ mc = tbl_mask_cache_alloc(MC_DEFAULT_HASH_ENTRIES);
+ if (!mc)
+ return -ENOMEM;
+
+ ma = tbl_mask_array_alloc(MASK_ARRAY_SIZE_MIN);
+ if (!ma)
+ goto free_mask_cache;
ti = table_instance_alloc(TBL_MIN_BUCKETS);
-
if (!ti)
- return -ENOMEM;
+ goto free_mask_array;
ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS);
if (!ufid_ti)
@@ -216,7 +434,8 @@
rcu_assign_pointer(table->ti, ti);
rcu_assign_pointer(table->ufid_ti, ufid_ti);
- INIT_LIST_HEAD(&table->mask_list);
+ rcu_assign_pointer(table->mask_array, ma);
+ rcu_assign_pointer(table->mask_cache, mc);
table->last_rehash = jiffies;
table->count = 0;
table->ufid_count = 0;
@@ -224,52 +443,70 @@
free_ti:
__table_instance_destroy(ti);
+free_mask_array:
+ __mask_array_destroy(ma);
+free_mask_cache:
+ __mask_cache_destroy(mc);
return -ENOMEM;
}
static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
{
- struct table_instance *ti = container_of(rcu, struct table_instance, rcu);
+ struct table_instance *ti;
+ ti = container_of(rcu, struct table_instance, rcu);
__table_instance_destroy(ti);
}
-static void table_instance_destroy(struct table_instance *ti,
- struct table_instance *ufid_ti,
- bool deferred)
+static void table_instance_flow_free(struct flow_table *table,
+ struct table_instance *ti,
+ struct table_instance *ufid_ti,
+ struct sw_flow *flow)
+{
+ hlist_del_rcu(&flow->flow_table.node[ti->node_ver]);
+ table->count--;
+
+ if (ovs_identifier_is_ufid(&flow->id)) {
+ hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]);
+ table->ufid_count--;
+ }
+
+ flow_mask_remove(table, flow->mask);
+}
+
+/* Must be called with OVS mutex held. */
+void table_instance_flow_flush(struct flow_table *table,
+ struct table_instance *ti,
+ struct table_instance *ufid_ti)
{
int i;
- if (!ti)
- return;
-
- BUG_ON(!ufid_ti);
- if (ti->keep_flows)
- goto skip_flows;
-
for (i = 0; i < ti->n_buckets; i++) {
- struct sw_flow *flow;
- struct hlist_head *head = flex_array_get(ti->buckets, i);
+ struct hlist_head *head = &ti->buckets[i];
struct hlist_node *n;
- int ver = ti->node_ver;
- int ufid_ver = ufid_ti->node_ver;
+ struct sw_flow *flow;
- hlist_for_each_entry_safe(flow, n, head, flow_table.node[ver]) {
- hlist_del_rcu(&flow->flow_table.node[ver]);
- if (ovs_identifier_is_ufid(&flow->id))
- hlist_del_rcu(&flow->ufid_table.node[ufid_ver]);
- ovs_flow_free(flow, deferred);
+ hlist_for_each_entry_safe(flow, n, head,
+ flow_table.node[ti->node_ver]) {
+
+ table_instance_flow_free(table, ti, ufid_ti,
+ flow);
+ ovs_flow_free(flow, true);
}
}
-skip_flows:
- if (deferred) {
- call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
- call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb);
- } else {
- __table_instance_destroy(ti);
- __table_instance_destroy(ufid_ti);
+ if (WARN_ON(table->count != 0 ||
+ table->ufid_count != 0)) {
+ table->count = 0;
+ table->ufid_count = 0;
}
+}
+
+static void table_instance_destroy(struct table_instance *ti,
+ struct table_instance *ufid_ti)
+{
+ call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
+ call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb);
}
/* No need for locking this function is called from RCU callback or
@@ -279,8 +516,12 @@
{
struct table_instance *ti = rcu_dereference_raw(table->ti);
struct table_instance *ufid_ti = rcu_dereference_raw(table->ufid_ti);
+ struct mask_cache *mc = rcu_dereference_raw(table->mask_cache);
+ struct mask_array *ma = rcu_dereference_raw(table->mask_array);
- table_instance_destroy(ti, ufid_ti, false);
+ call_rcu(&mc->rcu, mask_cache_rcu_cb);
+ call_rcu(&ma->rcu, mask_array_rcu_cb);
+ table_instance_destroy(ti, ufid_ti);
}
struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
@@ -294,7 +535,7 @@
ver = ti->node_ver;
while (*bucket < ti->n_buckets) {
i = 0;
- head = flex_array_get(ti->buckets, *bucket);
+ head = &ti->buckets[*bucket];
hlist_for_each_entry_rcu(flow, head, flow_table.node[ver]) {
if (i < *last) {
i++;
@@ -313,8 +554,7 @@
static struct hlist_head *find_bucket(struct table_instance *ti, u32 hash)
{
hash = jhash_1word(hash, ti->hash_seed);
- return flex_array_get(ti->buckets,
- (hash & (ti->n_buckets - 1)));
+ return &ti->buckets[hash & (ti->n_buckets - 1)];
}
static void table_instance_insert(struct table_instance *ti,
@@ -347,21 +587,19 @@
/* Insert in new table. */
for (i = 0; i < old->n_buckets; i++) {
struct sw_flow *flow;
- struct hlist_head *head;
-
- head = flex_array_get(old->buckets, i);
+ struct hlist_head *head = &old->buckets[i];
if (ufid)
- hlist_for_each_entry(flow, head,
- ufid_table.node[old_ver])
+ hlist_for_each_entry_rcu(flow, head,
+ ufid_table.node[old_ver],
+ lockdep_ovsl_is_held())
ufid_table_instance_insert(new, flow);
else
- hlist_for_each_entry(flow, head,
- flow_table.node[old_ver])
+ hlist_for_each_entry_rcu(flow, head,
+ flow_table.node[old_ver],
+ lockdep_ovsl_is_held())
table_instance_insert(new, flow);
}
-
- old->keep_flows = true;
}
static struct table_instance *table_instance_rehash(struct table_instance *ti,
@@ -396,10 +634,9 @@
rcu_assign_pointer(flow_table->ti, new_ti);
rcu_assign_pointer(flow_table->ufid_ti, new_ufid_ti);
flow_table->last_rehash = jiffies;
- flow_table->count = 0;
- flow_table->ufid_count = 0;
- table_instance_destroy(old_ti, old_ufid_ti, true);
+ table_instance_flow_flush(flow_table, old_ti, old_ufid_ti);
+ table_instance_destroy(old_ti, old_ufid_ti);
return 0;
err_free_ti:
@@ -410,13 +647,10 @@
static u32 flow_hash(const struct sw_flow_key *key,
const struct sw_flow_key_range *range)
{
- int key_start = range->start;
- int key_end = range->end;
- const u32 *hash_key = (const u32 *)((const u8 *)key + key_start);
- int hash_u32s = (key_end - key_start) >> 2;
+ const u32 *hash_key = (const u32 *)((const u8 *)key + range->start);
/* Make sure number of hash bytes are multiple of u32. */
- BUILD_BUG_ON(sizeof(long) % sizeof(u32));
+ int hash_u32s = range_n_bytes(range) >> 2;
return jhash2(hash_key, hash_u32s, 0);
}
@@ -427,7 +661,7 @@
return 0;
else
return rounddown(offsetof(struct sw_flow_key, phy),
- sizeof(long));
+ sizeof(long));
}
static bool cmp_key(const struct sw_flow_key *key1,
@@ -439,7 +673,7 @@
long diffs = 0;
int i;
- for (i = key_start; i < key_end; i += sizeof(long))
+ for (i = key_start; i < key_end; i += sizeof(long))
diffs |= *cp1++ ^ *cp2++;
return diffs == 0;
@@ -465,7 +699,8 @@
static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
const struct sw_flow_key *unmasked,
- const struct sw_flow_mask *mask)
+ const struct sw_flow_mask *mask,
+ u32 *n_mask_hit)
{
struct sw_flow *flow;
struct hlist_head *head;
@@ -475,7 +710,10 @@
ovs_flow_mask_key(&masked_key, unmasked, false, mask);
hash = flow_hash(&masked_key, &mask->range);
head = find_bucket(ti, hash);
- hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver]) {
+ (*n_mask_hit)++;
+
+ hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver],
+ lockdep_ovsl_is_held()) {
if (flow->mask == mask && flow->flow_table.hash == hash &&
flow_cmp_masked_key(flow, &masked_key, &mask->range))
return flow;
@@ -483,46 +721,175 @@
return NULL;
}
-struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
- const struct sw_flow_key *key,
- u32 *n_mask_hit)
+/* Flow lookup does full lookup on flow table. It starts with
+ * mask from index passed in *index.
+ * This function MUST be called with BH disabled due to the use
+ * of CPU specific variables.
+ */
+static struct sw_flow *flow_lookup(struct flow_table *tbl,
+ struct table_instance *ti,
+ struct mask_array *ma,
+ const struct sw_flow_key *key,
+ u32 *n_mask_hit,
+ u32 *n_cache_hit,
+ u32 *index)
{
- struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
- struct sw_flow_mask *mask;
+ struct mask_array_stats *stats = this_cpu_ptr(ma->masks_usage_stats);
struct sw_flow *flow;
+ struct sw_flow_mask *mask;
+ int i;
+
+ if (likely(*index < ma->max)) {
+ mask = rcu_dereference_ovsl(ma->masks[*index]);
+ if (mask) {
+ flow = masked_flow_lookup(ti, key, mask, n_mask_hit);
+ if (flow) {
+ u64_stats_update_begin(&stats->syncp);
+ stats->usage_cntrs[*index]++;
+ u64_stats_update_end(&stats->syncp);
+ (*n_cache_hit)++;
+ return flow;
+ }
+ }
+ }
+
+ for (i = 0; i < ma->max; i++) {
+
+ if (i == *index)
+ continue;
+
+ mask = rcu_dereference_ovsl(ma->masks[i]);
+ if (unlikely(!mask))
+ break;
+
+ flow = masked_flow_lookup(ti, key, mask, n_mask_hit);
+ if (flow) { /* Found */
+ *index = i;
+ u64_stats_update_begin(&stats->syncp);
+ stats->usage_cntrs[*index]++;
+ u64_stats_update_end(&stats->syncp);
+ return flow;
+ }
+ }
+
+ return NULL;
+}
+
+/*
+ * mask_cache maps flow to probable mask. This cache is not tightly
+ * coupled cache, It means updates to mask list can result in inconsistent
+ * cache entry in mask cache.
+ * This is per cpu cache and is divided in MC_HASH_SEGS segments.
+ * In case of a hash collision the entry is hashed in next segment.
+ * */
+struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
+ const struct sw_flow_key *key,
+ u32 skb_hash,
+ u32 *n_mask_hit,
+ u32 *n_cache_hit)
+{
+ struct mask_cache *mc = rcu_dereference(tbl->mask_cache);
+ struct mask_array *ma = rcu_dereference(tbl->mask_array);
+ struct table_instance *ti = rcu_dereference(tbl->ti);
+ struct mask_cache_entry *entries, *ce;
+ struct sw_flow *flow;
+ u32 hash;
+ int seg;
*n_mask_hit = 0;
- list_for_each_entry_rcu(mask, &tbl->mask_list, list) {
- (*n_mask_hit)++;
- flow = masked_flow_lookup(ti, key, mask);
- if (flow) /* Found */
- return flow;
+ *n_cache_hit = 0;
+ if (unlikely(!skb_hash || mc->cache_size == 0)) {
+ u32 mask_index = 0;
+ u32 cache = 0;
+
+ return flow_lookup(tbl, ti, ma, key, n_mask_hit, &cache,
+ &mask_index);
}
- return NULL;
+
+ /* Pre and post recirulation flows usually have the same skb_hash
+ * value. To avoid hash collisions, rehash the 'skb_hash' with
+ * 'recirc_id'. */
+ if (key->recirc_id)
+ skb_hash = jhash_1word(skb_hash, key->recirc_id);
+
+ ce = NULL;
+ hash = skb_hash;
+ entries = this_cpu_ptr(mc->mask_cache);
+
+ /* Find the cache entry 'ce' to operate on. */
+ for (seg = 0; seg < MC_HASH_SEGS; seg++) {
+ int index = hash & (mc->cache_size - 1);
+ struct mask_cache_entry *e;
+
+ e = &entries[index];
+ if (e->skb_hash == skb_hash) {
+ flow = flow_lookup(tbl, ti, ma, key, n_mask_hit,
+ n_cache_hit, &e->mask_index);
+ if (!flow)
+ e->skb_hash = 0;
+ return flow;
+ }
+
+ if (!ce || e->skb_hash < ce->skb_hash)
+ ce = e; /* A better replacement cache candidate. */
+
+ hash >>= MC_HASH_SHIFT;
+ }
+
+ /* Cache miss, do full lookup. */
+ flow = flow_lookup(tbl, ti, ma, key, n_mask_hit, n_cache_hit,
+ &ce->mask_index);
+ if (flow)
+ ce->skb_hash = skb_hash;
+
+ *n_cache_hit = 0;
+ return flow;
}
struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl,
const struct sw_flow_key *key)
{
+ struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
+ struct mask_array *ma = rcu_dereference_ovsl(tbl->mask_array);
u32 __always_unused n_mask_hit;
+ u32 __always_unused n_cache_hit;
+ struct sw_flow *flow;
+ u32 index = 0;
- return ovs_flow_tbl_lookup_stats(tbl, key, &n_mask_hit);
+ /* This function gets called trough the netlink interface and therefore
+ * is preemptible. However, flow_lookup() function needs to be called
+ * with BH disabled due to CPU specific variables.
+ */
+ local_bh_disable();
+ flow = flow_lookup(tbl, ti, ma, key, &n_mask_hit, &n_cache_hit, &index);
+ local_bh_enable();
+ return flow;
}
struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl,
const struct sw_flow_match *match)
{
- struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
- struct sw_flow_mask *mask;
- struct sw_flow *flow;
+ struct mask_array *ma = ovsl_dereference(tbl->mask_array);
+ int i;
/* Always called under ovs-mutex. */
- list_for_each_entry(mask, &tbl->mask_list, list) {
- flow = masked_flow_lookup(ti, match->key, mask);
+ for (i = 0; i < ma->max; i++) {
+ struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
+ u32 __always_unused n_mask_hit;
+ struct sw_flow_mask *mask;
+ struct sw_flow *flow;
+
+ mask = ovsl_dereference(ma->masks[i]);
+ if (!mask)
+ continue;
+
+ flow = masked_flow_lookup(ti, match->key, mask, &n_mask_hit);
if (flow && ovs_identifier_is_key(&flow->id) &&
- ovs_flow_cmp_unmasked_key(flow, match))
+ ovs_flow_cmp_unmasked_key(flow, match)) {
return flow;
+ }
}
+
return NULL;
}
@@ -540,7 +907,8 @@
return !memcmp(flow->id.ufid, sfid->ufid, sfid->ufid_len);
}
-bool ovs_flow_cmp(const struct sw_flow *flow, const struct sw_flow_match *match)
+bool ovs_flow_cmp(const struct sw_flow *flow,
+ const struct sw_flow_match *match)
{
if (ovs_identifier_is_ufid(&flow->id))
return flow_cmp_masked_key(flow, match->key, &match->range);
@@ -558,7 +926,8 @@
hash = ufid_hash(ufid);
head = find_bucket(ti, hash);
- hlist_for_each_entry_rcu(flow, head, ufid_table.node[ti->node_ver]) {
+ hlist_for_each_entry_rcu(flow, head, ufid_table.node[ti->node_ver],
+ lockdep_ovsl_is_held()) {
if (flow->ufid_table.hash == hash &&
ovs_flow_cmp_ufid(flow, ufid))
return flow;
@@ -568,37 +937,21 @@
int ovs_flow_tbl_num_masks(const struct flow_table *table)
{
- struct sw_flow_mask *mask;
- int num = 0;
+ struct mask_array *ma = rcu_dereference_ovsl(table->mask_array);
+ return READ_ONCE(ma->count);
+}
- list_for_each_entry(mask, &table->mask_list, list)
- num++;
+u32 ovs_flow_tbl_masks_cache_size(const struct flow_table *table)
+{
+ struct mask_cache *mc = rcu_dereference_ovsl(table->mask_cache);
- return num;
+ return READ_ONCE(mc->cache_size);
}
static struct table_instance *table_instance_expand(struct table_instance *ti,
bool ufid)
{
return table_instance_rehash(ti, ti->n_buckets * 2, ufid);
-}
-
-/* Remove 'mask' from the mask list, if it is not needed any more. */
-static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask)
-{
- if (mask) {
- /* ovs-lock is required to protect mask-refcount and
- * mask list.
- */
- ASSERT_OVSL();
- BUG_ON(!mask->ref_count);
- mask->ref_count--;
-
- if (!mask->ref_count) {
- list_del_rcu(&mask->list);
- kfree_rcu(mask, rcu);
- }
- }
}
/* Must be called with OVS mutex held. */
@@ -608,17 +961,7 @@
struct table_instance *ufid_ti = ovsl_dereference(table->ufid_ti);
BUG_ON(table->count == 0);
- hlist_del_rcu(&flow->flow_table.node[ti->node_ver]);
- table->count--;
- if (ovs_identifier_is_ufid(&flow->id)) {
- hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]);
- table->ufid_count--;
- }
-
- /* RCU delete the mask. 'flow->mask' is not NULLed, as it should be
- * accessible as long as the RCU read lock is held.
- */
- flow_mask_remove(table, flow->mask);
+ table_instance_flow_free(table, ti, ufid_ti, flow);
}
static struct sw_flow_mask *mask_alloc(void)
@@ -646,13 +989,16 @@
static struct sw_flow_mask *flow_mask_find(const struct flow_table *tbl,
const struct sw_flow_mask *mask)
{
- struct list_head *ml;
+ struct mask_array *ma;
+ int i;
- list_for_each(ml, &tbl->mask_list) {
- struct sw_flow_mask *m;
- m = container_of(ml, struct sw_flow_mask, list);
- if (mask_equal(mask, m))
- return m;
+ ma = ovsl_dereference(tbl->mask_array);
+ for (i = 0; i < ma->max; i++) {
+ struct sw_flow_mask *t;
+ t = ovsl_dereference(ma->masks[i]);
+
+ if (t && mask_equal(mask, t))
+ return t;
}
return NULL;
@@ -663,6 +1009,7 @@
const struct sw_flow_mask *new)
{
struct sw_flow_mask *mask;
+
mask = flow_mask_find(tbl, new);
if (!mask) {
/* Allocate a new mask if none exsits. */
@@ -671,7 +1018,12 @@
return -ENOMEM;
mask->key = new->key;
mask->range = new->range;
- list_add_rcu(&mask->list, &tbl->mask_list);
+
+ /* Add mask to mask-list. */
+ if (tbl_mask_array_add_mask(tbl, mask)) {
+ kfree(mask);
+ return -ENOMEM;
+ }
} else {
BUG_ON(!mask->ref_count);
mask->ref_count++;
@@ -743,6 +1095,99 @@
return 0;
}
+static int compare_mask_and_count(const void *a, const void *b)
+{
+ const struct mask_count *mc_a = a;
+ const struct mask_count *mc_b = b;
+
+ return (s64)mc_b->counter - (s64)mc_a->counter;
+}
+
+/* Must be called with OVS mutex held. */
+void ovs_flow_masks_rebalance(struct flow_table *table)
+{
+ struct mask_array *ma = rcu_dereference_ovsl(table->mask_array);
+ struct mask_count *masks_and_count;
+ struct mask_array *new;
+ int masks_entries = 0;
+ int i;
+
+ /* Build array of all current entries with use counters. */
+ masks_and_count = kmalloc_array(ma->max, sizeof(*masks_and_count),
+ GFP_KERNEL);
+ if (!masks_and_count)
+ return;
+
+ for (i = 0; i < ma->max; i++) {
+ struct sw_flow_mask *mask;
+ int cpu;
+
+ mask = rcu_dereference_ovsl(ma->masks[i]);
+ if (unlikely(!mask))
+ break;
+
+ masks_and_count[i].index = i;
+ masks_and_count[i].counter = 0;
+
+ for_each_possible_cpu(cpu) {
+ struct mask_array_stats *stats;
+ unsigned int start;
+ u64 counter;
+
+ stats = per_cpu_ptr(ma->masks_usage_stats, cpu);
+ do {
+ start = u64_stats_fetch_begin_irq(&stats->syncp);
+ counter = stats->usage_cntrs[i];
+ } while (u64_stats_fetch_retry_irq(&stats->syncp,
+ start));
+
+ masks_and_count[i].counter += counter;
+ }
+
+ /* Subtract the zero count value. */
+ masks_and_count[i].counter -= ma->masks_usage_zero_cntr[i];
+
+ /* Rather than calling tbl_mask_array_reset_counters()
+ * below when no change is needed, do it inline here.
+ */
+ ma->masks_usage_zero_cntr[i] += masks_and_count[i].counter;
+ }
+
+ if (i == 0)
+ goto free_mask_entries;
+
+ /* Sort the entries */
+ masks_entries = i;
+ sort(masks_and_count, masks_entries, sizeof(*masks_and_count),
+ compare_mask_and_count, NULL);
+
+ /* If the order is the same, nothing to do... */
+ for (i = 0; i < masks_entries; i++) {
+ if (i != masks_and_count[i].index)
+ break;
+ }
+ if (i == masks_entries)
+ goto free_mask_entries;
+
+ /* Rebuilt the new list in order of usage. */
+ new = tbl_mask_array_alloc(ma->max);
+ if (!new)
+ goto free_mask_entries;
+
+ for (i = 0; i < masks_entries; i++) {
+ int index = masks_and_count[i].index;
+
+ if (ovsl_dereference(ma->masks[index]))
+ new->masks[new->count++] = ma->masks[index];
+ }
+
+ rcu_assign_pointer(table->mask_array, new);
+ call_rcu(&ma->rcu, mask_array_rcu_cb);
+
+free_mask_entries:
+ kfree(masks_and_count);
+}
+
/* Initializes the flow module.
* Returns zero if successful or a negative error code. */
int ovs_flow_init(void)
@@ -752,13 +1197,13 @@
flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow)
+ (nr_cpu_ids
- * sizeof(struct flow_stats *)),
+ * sizeof(struct sw_flow_stats *)),
0, 0, NULL);
if (flow_cache == NULL)
return -ENOMEM;
flow_stats_cache
- = kmem_cache_create("sw_flow_stats", sizeof(struct flow_stats),
+ = kmem_cache_create("sw_flow_stats", sizeof(struct sw_flow_stats),
0, SLAB_HWCACHE_ALIGN, NULL);
if (flow_stats_cache == NULL) {
kmem_cache_destroy(flow_cache);
--
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