diff options
author | Florian Westphal <fw@strlen.de> | 2017-07-17 14:57:26 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2017-07-18 21:13:41 +0300 |
commit | 09c7570480f7544ffbf8e6db365208b0b0c154c6 (patch) | |
tree | 65c8b2560b2c819b8948244fa707d4fa128b4da9 /net/core/flow.c | |
parent | bd45c539bf56650fb8fbab09c36f4b9afcbd4e1c (diff) | |
download | linux-09c7570480f7544ffbf8e6db365208b0b0c154c6.tar.xz |
xfrm: remove flow cache
After rcu conversions performance degradation in forward tests isn't that
noticeable anymore.
See next patch for some numbers.
A followup patcg could then also remove genid from the policies
as we do not cache bundles anymore.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/flow.c')
-rw-r--r-- | net/core/flow.c | 516 |
1 files changed, 0 insertions, 516 deletions
diff --git a/net/core/flow.c b/net/core/flow.c deleted file mode 100644 index f7f5d1932a27..000000000000 --- a/net/core/flow.c +++ /dev/null @@ -1,516 +0,0 @@ -/* flow.c: Generic flow cache. - * - * Copyright (C) 2003 Alexey N. Kuznetsov (kuznet@ms2.inr.ac.ru) - * Copyright (C) 2003 David S. Miller (davem@redhat.com) - */ - -#include <linux/kernel.h> -#include <linux/module.h> -#include <linux/list.h> -#include <linux/jhash.h> -#include <linux/interrupt.h> -#include <linux/mm.h> -#include <linux/random.h> -#include <linux/init.h> -#include <linux/slab.h> -#include <linux/smp.h> -#include <linux/completion.h> -#include <linux/percpu.h> -#include <linux/bitops.h> -#include <linux/notifier.h> -#include <linux/cpu.h> -#include <linux/cpumask.h> -#include <linux/mutex.h> -#include <net/flow.h> -#include <linux/atomic.h> -#include <linux/security.h> -#include <net/net_namespace.h> - -struct flow_cache_entry { - union { - struct hlist_node hlist; - struct list_head gc_list; - } u; - struct net *net; - u16 family; - u8 dir; - u32 genid; - struct flowi key; - struct flow_cache_object *object; -}; - -struct flow_flush_info { - struct flow_cache *cache; - atomic_t cpuleft; - struct completion completion; -}; - -static struct kmem_cache *flow_cachep __read_mostly; - -#define flow_cache_hash_size(cache) (1U << (cache)->hash_shift) -#define FLOW_HASH_RND_PERIOD (10 * 60 * HZ) - -static void flow_cache_new_hashrnd(unsigned long arg) -{ - struct flow_cache *fc = (void *) arg; - int i; - - for_each_possible_cpu(i) - per_cpu_ptr(fc->percpu, i)->hash_rnd_recalc = 1; - - fc->rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD; - add_timer(&fc->rnd_timer); -} - -static int flow_entry_valid(struct flow_cache_entry *fle, - struct netns_xfrm *xfrm) -{ - if (atomic_read(&xfrm->flow_cache_genid) != fle->genid) - return 0; - if (fle->object && !fle->object->ops->check(fle->object)) - return 0; - return 1; -} - -static void flow_entry_kill(struct flow_cache_entry *fle, - struct netns_xfrm *xfrm) -{ - if (fle->object) - fle->object->ops->delete(fle->object); - kmem_cache_free(flow_cachep, fle); -} - -static void flow_cache_gc_task(struct work_struct *work) -{ - struct list_head gc_list; - struct flow_cache_entry *fce, *n; - struct netns_xfrm *xfrm = container_of(work, struct netns_xfrm, - flow_cache_gc_work); - - INIT_LIST_HEAD(&gc_list); - spin_lock_bh(&xfrm->flow_cache_gc_lock); - list_splice_tail_init(&xfrm->flow_cache_gc_list, &gc_list); - spin_unlock_bh(&xfrm->flow_cache_gc_lock); - - list_for_each_entry_safe(fce, n, &gc_list, u.gc_list) { - flow_entry_kill(fce, xfrm); - atomic_dec(&xfrm->flow_cache_gc_count); - } -} - -static void flow_cache_queue_garbage(struct flow_cache_percpu *fcp, - unsigned int deleted, - struct list_head *gc_list, - struct netns_xfrm *xfrm) -{ - if (deleted) { - atomic_add(deleted, &xfrm->flow_cache_gc_count); - fcp->hash_count -= deleted; - spin_lock_bh(&xfrm->flow_cache_gc_lock); - list_splice_tail(gc_list, &xfrm->flow_cache_gc_list); - spin_unlock_bh(&xfrm->flow_cache_gc_lock); - schedule_work(&xfrm->flow_cache_gc_work); - } -} - -static void __flow_cache_shrink(struct flow_cache *fc, - struct flow_cache_percpu *fcp, - unsigned int shrink_to) -{ - struct flow_cache_entry *fle; - struct hlist_node *tmp; - LIST_HEAD(gc_list); - unsigned int deleted = 0; - struct netns_xfrm *xfrm = container_of(fc, struct netns_xfrm, - flow_cache_global); - unsigned int i; - - for (i = 0; i < flow_cache_hash_size(fc); i++) { - unsigned int saved = 0; - - hlist_for_each_entry_safe(fle, tmp, - &fcp->hash_table[i], u.hlist) { - if (saved < shrink_to && - flow_entry_valid(fle, xfrm)) { - saved++; - } else { - deleted++; - hlist_del(&fle->u.hlist); - list_add_tail(&fle->u.gc_list, &gc_list); - } - } - } - - flow_cache_queue_garbage(fcp, deleted, &gc_list, xfrm); -} - -static void flow_cache_shrink(struct flow_cache *fc, - struct flow_cache_percpu *fcp) -{ - unsigned int shrink_to = fc->low_watermark / flow_cache_hash_size(fc); - - __flow_cache_shrink(fc, fcp, shrink_to); -} - -static void flow_new_hash_rnd(struct flow_cache *fc, - struct flow_cache_percpu *fcp) -{ - get_random_bytes(&fcp->hash_rnd, sizeof(u32)); - fcp->hash_rnd_recalc = 0; - __flow_cache_shrink(fc, fcp, 0); -} - -static u32 flow_hash_code(struct flow_cache *fc, - struct flow_cache_percpu *fcp, - const struct flowi *key, - unsigned int keysize) -{ - const u32 *k = (const u32 *) key; - const u32 length = keysize * sizeof(flow_compare_t) / sizeof(u32); - - return jhash2(k, length, fcp->hash_rnd) - & (flow_cache_hash_size(fc) - 1); -} - -/* I hear what you're saying, use memcmp. But memcmp cannot make - * important assumptions that we can here, such as alignment. - */ -static int flow_key_compare(const struct flowi *key1, const struct flowi *key2, - unsigned int keysize) -{ - const flow_compare_t *k1, *k1_lim, *k2; - - k1 = (const flow_compare_t *) key1; - k1_lim = k1 + keysize; - - k2 = (const flow_compare_t *) key2; - - do { - if (*k1++ != *k2++) - return 1; - } while (k1 < k1_lim); - - return 0; -} - -struct flow_cache_object * -flow_cache_lookup(struct net *net, const struct flowi *key, u16 family, u8 dir, - flow_resolve_t resolver, void *ctx) -{ - struct flow_cache *fc = &net->xfrm.flow_cache_global; - struct flow_cache_percpu *fcp; - struct flow_cache_entry *fle, *tfle; - struct flow_cache_object *flo; - unsigned int keysize; - unsigned int hash; - - local_bh_disable(); - fcp = this_cpu_ptr(fc->percpu); - - fle = NULL; - flo = NULL; - - keysize = flow_key_size(family); - if (!keysize) - goto nocache; - - /* Packet really early in init? Making flow_cache_init a - * pre-smp initcall would solve this. --RR */ - if (!fcp->hash_table) - goto nocache; - - if (fcp->hash_rnd_recalc) - flow_new_hash_rnd(fc, fcp); - - hash = flow_hash_code(fc, fcp, key, keysize); - hlist_for_each_entry(tfle, &fcp->hash_table[hash], u.hlist) { - if (tfle->net == net && - tfle->family == family && - tfle->dir == dir && - flow_key_compare(key, &tfle->key, keysize) == 0) { - fle = tfle; - break; - } - } - - if (unlikely(!fle)) { - if (fcp->hash_count > fc->high_watermark) - flow_cache_shrink(fc, fcp); - - if (atomic_read(&net->xfrm.flow_cache_gc_count) > - 2 * num_online_cpus() * fc->high_watermark) { - flo = ERR_PTR(-ENOBUFS); - goto ret_object; - } - - fle = kmem_cache_alloc(flow_cachep, GFP_ATOMIC); - if (fle) { - fle->net = net; - fle->family = family; - fle->dir = dir; - memcpy(&fle->key, key, keysize * sizeof(flow_compare_t)); - fle->object = NULL; - hlist_add_head(&fle->u.hlist, &fcp->hash_table[hash]); - fcp->hash_count++; - } - } else if (likely(fle->genid == atomic_read(&net->xfrm.flow_cache_genid))) { - flo = fle->object; - if (!flo) - goto ret_object; - flo = flo->ops->get(flo); - if (flo) - goto ret_object; - } else if (fle->object) { - flo = fle->object; - flo->ops->delete(flo); - fle->object = NULL; - } - -nocache: - flo = NULL; - if (fle) { - flo = fle->object; - fle->object = NULL; - } - flo = resolver(net, key, family, dir, flo, ctx); - if (fle) { - fle->genid = atomic_read(&net->xfrm.flow_cache_genid); - if (!IS_ERR(flo)) - fle->object = flo; - else - fle->genid--; - } else { - if (!IS_ERR_OR_NULL(flo)) - flo->ops->delete(flo); - } -ret_object: - local_bh_enable(); - return flo; -} -EXPORT_SYMBOL(flow_cache_lookup); - -static void flow_cache_flush_tasklet(unsigned long data) -{ - struct flow_flush_info *info = (void *)data; - struct flow_cache *fc = info->cache; - struct flow_cache_percpu *fcp; - struct flow_cache_entry *fle; - struct hlist_node *tmp; - LIST_HEAD(gc_list); - unsigned int deleted = 0; - struct netns_xfrm *xfrm = container_of(fc, struct netns_xfrm, - flow_cache_global); - unsigned int i; - - fcp = this_cpu_ptr(fc->percpu); - for (i = 0; i < flow_cache_hash_size(fc); i++) { - hlist_for_each_entry_safe(fle, tmp, - &fcp->hash_table[i], u.hlist) { - if (flow_entry_valid(fle, xfrm)) - continue; - - deleted++; - hlist_del(&fle->u.hlist); - list_add_tail(&fle->u.gc_list, &gc_list); - } - } - - flow_cache_queue_garbage(fcp, deleted, &gc_list, xfrm); - - if (atomic_dec_and_test(&info->cpuleft)) - complete(&info->completion); -} - -/* - * Return whether a cpu needs flushing. Conservatively, we assume - * the presence of any entries means the core may require flushing, - * since the flow_cache_ops.check() function may assume it's running - * on the same core as the per-cpu cache component. - */ -static int flow_cache_percpu_empty(struct flow_cache *fc, int cpu) -{ - struct flow_cache_percpu *fcp; - unsigned int i; - - fcp = per_cpu_ptr(fc->percpu, cpu); - for (i = 0; i < flow_cache_hash_size(fc); i++) - if (!hlist_empty(&fcp->hash_table[i])) - return 0; - return 1; -} - -static void flow_cache_flush_per_cpu(void *data) -{ - struct flow_flush_info *info = data; - struct tasklet_struct *tasklet; - - tasklet = &this_cpu_ptr(info->cache->percpu)->flush_tasklet; - tasklet->data = (unsigned long)info; - tasklet_schedule(tasklet); -} - -void flow_cache_flush(struct net *net) -{ - struct flow_flush_info info; - cpumask_var_t mask; - int i, self; - - /* Track which cpus need flushing to avoid disturbing all cores. */ - if (!alloc_cpumask_var(&mask, GFP_KERNEL)) - return; - cpumask_clear(mask); - - /* Don't want cpus going down or up during this. */ - get_online_cpus(); - mutex_lock(&net->xfrm.flow_flush_sem); - info.cache = &net->xfrm.flow_cache_global; - for_each_online_cpu(i) - if (!flow_cache_percpu_empty(info.cache, i)) - cpumask_set_cpu(i, mask); - atomic_set(&info.cpuleft, cpumask_weight(mask)); - if (atomic_read(&info.cpuleft) == 0) - goto done; - - init_completion(&info.completion); - - local_bh_disable(); - self = cpumask_test_and_clear_cpu(smp_processor_id(), mask); - on_each_cpu_mask(mask, flow_cache_flush_per_cpu, &info, 0); - if (self) - flow_cache_flush_tasklet((unsigned long)&info); - local_bh_enable(); - - wait_for_completion(&info.completion); - -done: - mutex_unlock(&net->xfrm.flow_flush_sem); - put_online_cpus(); - free_cpumask_var(mask); -} - -static void flow_cache_flush_task(struct work_struct *work) -{ - struct netns_xfrm *xfrm = container_of(work, struct netns_xfrm, - flow_cache_flush_work); - struct net *net = container_of(xfrm, struct net, xfrm); - - flow_cache_flush(net); -} - -void flow_cache_flush_deferred(struct net *net) -{ - schedule_work(&net->xfrm.flow_cache_flush_work); -} - -static int flow_cache_cpu_prepare(struct flow_cache *fc, int cpu) -{ - struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, cpu); - unsigned int sz = sizeof(struct hlist_head) * flow_cache_hash_size(fc); - - if (!fcp->hash_table) { - fcp->hash_table = kzalloc_node(sz, GFP_KERNEL, cpu_to_node(cpu)); - if (!fcp->hash_table) { - pr_err("NET: failed to allocate flow cache sz %u\n", sz); - return -ENOMEM; - } - fcp->hash_rnd_recalc = 1; - fcp->hash_count = 0; - tasklet_init(&fcp->flush_tasklet, flow_cache_flush_tasklet, 0); - } - return 0; -} - -static int flow_cache_cpu_up_prep(unsigned int cpu, struct hlist_node *node) -{ - struct flow_cache *fc = hlist_entry_safe(node, struct flow_cache, node); - - return flow_cache_cpu_prepare(fc, cpu); -} - -static int flow_cache_cpu_dead(unsigned int cpu, struct hlist_node *node) -{ - struct flow_cache *fc = hlist_entry_safe(node, struct flow_cache, node); - struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, cpu); - - __flow_cache_shrink(fc, fcp, 0); - return 0; -} - -int flow_cache_init(struct net *net) -{ - int i; - struct flow_cache *fc = &net->xfrm.flow_cache_global; - - if (!flow_cachep) - flow_cachep = kmem_cache_create("flow_cache", - sizeof(struct flow_cache_entry), - 0, SLAB_PANIC, NULL); - spin_lock_init(&net->xfrm.flow_cache_gc_lock); - INIT_LIST_HEAD(&net->xfrm.flow_cache_gc_list); - INIT_WORK(&net->xfrm.flow_cache_gc_work, flow_cache_gc_task); - INIT_WORK(&net->xfrm.flow_cache_flush_work, flow_cache_flush_task); - mutex_init(&net->xfrm.flow_flush_sem); - atomic_set(&net->xfrm.flow_cache_gc_count, 0); - - fc->hash_shift = 10; - fc->low_watermark = 2 * flow_cache_hash_size(fc); - fc->high_watermark = 4 * flow_cache_hash_size(fc); - - fc->percpu = alloc_percpu(struct flow_cache_percpu); - if (!fc->percpu) - return -ENOMEM; - - if (cpuhp_state_add_instance(CPUHP_NET_FLOW_PREPARE, &fc->node)) - goto err; - - setup_timer(&fc->rnd_timer, flow_cache_new_hashrnd, - (unsigned long) fc); - fc->rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD; - add_timer(&fc->rnd_timer); - - return 0; - -err: - for_each_possible_cpu(i) { - struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, i); - kfree(fcp->hash_table); - fcp->hash_table = NULL; - } - - free_percpu(fc->percpu); - fc->percpu = NULL; - - return -ENOMEM; -} -EXPORT_SYMBOL(flow_cache_init); - -void flow_cache_fini(struct net *net) -{ - int i; - struct flow_cache *fc = &net->xfrm.flow_cache_global; - - del_timer_sync(&fc->rnd_timer); - - cpuhp_state_remove_instance_nocalls(CPUHP_NET_FLOW_PREPARE, &fc->node); - - for_each_possible_cpu(i) { - struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, i); - kfree(fcp->hash_table); - fcp->hash_table = NULL; - } - - free_percpu(fc->percpu); - fc->percpu = NULL; -} -EXPORT_SYMBOL(flow_cache_fini); - -void __init flow_cache_hp_init(void) -{ - int ret; - - ret = cpuhp_setup_state_multi(CPUHP_NET_FLOW_PREPARE, - "net/flow:prepare", - flow_cache_cpu_up_prep, - flow_cache_cpu_dead); - WARN_ON(ret < 0); -} |