flow: structurize flow cache
Group all per-cpu data to one structure instead of having many globals. Also prepare the internals so that we can have multiple instances of the flow cache if needed. Only the kmem_cache is left as a global as all flow caches share the same element size, and benefit from using a common cache. Signed-off-by: Timo Teras <timo.teras@iki.fi> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Timo Teräs
David S. Miller
parent
ea2dea9dac
commit
d7997fe1f4
215
net/core/flow.c
215
net/core/flow.c
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@ -35,104 +35,105 @@ struct flow_cache_entry {
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atomic_t *object_ref;
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};
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atomic_t flow_cache_genid = ATOMIC_INIT(0);
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static u32 flow_hash_shift;
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#define flow_hash_size (1 << flow_hash_shift)
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static DEFINE_PER_CPU(struct flow_cache_entry **, flow_tables) = { NULL };
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#define flow_table(cpu) (per_cpu(flow_tables, cpu))
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static struct kmem_cache *flow_cachep __read_mostly;
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static int flow_lwm, flow_hwm;
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struct flow_percpu_info {
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int hash_rnd_recalc;
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struct flow_cache_percpu {
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struct flow_cache_entry ** hash_table;
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int hash_count;
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u32 hash_rnd;
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int count;
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int hash_rnd_recalc;
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struct tasklet_struct flush_tasklet;
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};
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static DEFINE_PER_CPU(struct flow_percpu_info, flow_hash_info) = { 0 };
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#define flow_hash_rnd_recalc(cpu) \
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(per_cpu(flow_hash_info, cpu).hash_rnd_recalc)
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#define flow_hash_rnd(cpu) \
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(per_cpu(flow_hash_info, cpu).hash_rnd)
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#define flow_count(cpu) \
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(per_cpu(flow_hash_info, cpu).count)
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static struct timer_list flow_hash_rnd_timer;
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#define FLOW_HASH_RND_PERIOD (10 * 60 * HZ)
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struct flow_flush_info {
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struct flow_cache * cache;
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atomic_t cpuleft;
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struct completion completion;
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};
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static DEFINE_PER_CPU(struct tasklet_struct, flow_flush_tasklets) = { NULL };
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#define flow_flush_tasklet(cpu) (&per_cpu(flow_flush_tasklets, cpu))
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struct flow_cache {
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u32 hash_shift;
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unsigned long order;
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struct flow_cache_percpu * percpu;
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struct notifier_block hotcpu_notifier;
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int low_watermark;
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int high_watermark;
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struct timer_list rnd_timer;
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};
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atomic_t flow_cache_genid = ATOMIC_INIT(0);
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static struct flow_cache flow_cache_global;
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static struct kmem_cache *flow_cachep;
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#define flow_cache_hash_size(cache) (1 << (cache)->hash_shift)
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#define FLOW_HASH_RND_PERIOD (10 * 60 * HZ)
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static void flow_cache_new_hashrnd(unsigned long arg)
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{
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struct flow_cache *fc = (void *) arg;
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int i;
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for_each_possible_cpu(i)
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flow_hash_rnd_recalc(i) = 1;
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per_cpu_ptr(fc->percpu, i)->hash_rnd_recalc = 1;
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flow_hash_rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD;
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add_timer(&flow_hash_rnd_timer);
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fc->rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD;
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add_timer(&fc->rnd_timer);
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}
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static void flow_entry_kill(int cpu, struct flow_cache_entry *fle)
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static void flow_entry_kill(struct flow_cache *fc,
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struct flow_cache_percpu *fcp,
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struct flow_cache_entry *fle)
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{
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if (fle->object)
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atomic_dec(fle->object_ref);
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kmem_cache_free(flow_cachep, fle);
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flow_count(cpu)--;
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fcp->hash_count--;
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}
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static void __flow_cache_shrink(int cpu, int shrink_to)
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static void __flow_cache_shrink(struct flow_cache *fc,
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struct flow_cache_percpu *fcp,
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int shrink_to)
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{
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struct flow_cache_entry *fle, **flp;
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int i;
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for (i = 0; i < flow_hash_size; i++) {
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for (i = 0; i < flow_cache_hash_size(fc); i++) {
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int k = 0;
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flp = &flow_table(cpu)[i];
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flp = &fcp->hash_table[i];
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while ((fle = *flp) != NULL && k < shrink_to) {
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k++;
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flp = &fle->next;
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}
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while ((fle = *flp) != NULL) {
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*flp = fle->next;
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flow_entry_kill(cpu, fle);
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flow_entry_kill(fc, fcp, fle);
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}
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}
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}
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static void flow_cache_shrink(int cpu)
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static void flow_cache_shrink(struct flow_cache *fc,
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struct flow_cache_percpu *fcp)
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{
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int shrink_to = flow_lwm / flow_hash_size;
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int shrink_to = fc->low_watermark / flow_cache_hash_size(fc);
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__flow_cache_shrink(cpu, shrink_to);
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__flow_cache_shrink(fc, fcp, shrink_to);
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}
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static void flow_new_hash_rnd(int cpu)
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static void flow_new_hash_rnd(struct flow_cache *fc,
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struct flow_cache_percpu *fcp)
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{
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get_random_bytes(&flow_hash_rnd(cpu), sizeof(u32));
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flow_hash_rnd_recalc(cpu) = 0;
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__flow_cache_shrink(cpu, 0);
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get_random_bytes(&fcp->hash_rnd, sizeof(u32));
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fcp->hash_rnd_recalc = 0;
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__flow_cache_shrink(fc, fcp, 0);
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}
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static u32 flow_hash_code(struct flowi *key, int cpu)
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static u32 flow_hash_code(struct flow_cache *fc,
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struct flow_cache_percpu *fcp,
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struct flowi *key)
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{
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u32 *k = (u32 *) key;
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return (jhash2(k, (sizeof(*key) / sizeof(u32)), flow_hash_rnd(cpu)) &
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(flow_hash_size - 1));
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return (jhash2(k, (sizeof(*key) / sizeof(u32)), fcp->hash_rnd)
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& (flow_cache_hash_size(fc) - 1));
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}
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#if (BITS_PER_LONG == 64)
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@ -168,24 +169,25 @@ static int flow_key_compare(struct flowi *key1, struct flowi *key2)
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void *flow_cache_lookup(struct net *net, struct flowi *key, u16 family, u8 dir,
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flow_resolve_t resolver)
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{
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struct flow_cache *fc = &flow_cache_global;
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struct flow_cache_percpu *fcp;
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struct flow_cache_entry *fle, **head;
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unsigned int hash;
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int cpu;
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local_bh_disable();
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cpu = smp_processor_id();
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fcp = per_cpu_ptr(fc->percpu, smp_processor_id());
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fle = NULL;
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/* Packet really early in init? Making flow_cache_init a
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* pre-smp initcall would solve this. --RR */
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if (!flow_table(cpu))
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if (!fcp->hash_table)
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goto nocache;
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if (flow_hash_rnd_recalc(cpu))
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flow_new_hash_rnd(cpu);
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hash = flow_hash_code(key, cpu);
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if (fcp->hash_rnd_recalc)
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flow_new_hash_rnd(fc, fcp);
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hash = flow_hash_code(fc, fcp, key);
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head = &flow_table(cpu)[hash];
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head = &fcp->hash_table[hash];
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for (fle = *head; fle; fle = fle->next) {
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if (fle->family == family &&
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fle->dir == dir &&
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@ -204,8 +206,8 @@ void *flow_cache_lookup(struct net *net, struct flowi *key, u16 family, u8 dir,
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}
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if (!fle) {
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if (flow_count(cpu) > flow_hwm)
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flow_cache_shrink(cpu);
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if (fcp->hash_count > fc->high_watermark)
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flow_cache_shrink(fc, fcp);
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fle = kmem_cache_alloc(flow_cachep, GFP_ATOMIC);
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if (fle) {
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@ -215,7 +217,7 @@ void *flow_cache_lookup(struct net *net, struct flowi *key, u16 family, u8 dir,
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fle->dir = dir;
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memcpy(&fle->key, key, sizeof(*key));
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fle->object = NULL;
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flow_count(cpu)++;
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fcp->hash_count++;
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}
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}
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@ -249,14 +251,15 @@ nocache:
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static void flow_cache_flush_tasklet(unsigned long data)
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{
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struct flow_flush_info *info = (void *)data;
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struct flow_cache *fc = info->cache;
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struct flow_cache_percpu *fcp;
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int i;
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int cpu;
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cpu = smp_processor_id();
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for (i = 0; i < flow_hash_size; i++) {
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fcp = per_cpu_ptr(fc->percpu, smp_processor_id());
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for (i = 0; i < flow_cache_hash_size(fc); i++) {
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struct flow_cache_entry *fle;
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fle = flow_table(cpu)[i];
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fle = fcp->hash_table[i];
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for (; fle; fle = fle->next) {
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unsigned genid = atomic_read(&flow_cache_genid);
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@ -272,7 +275,6 @@ static void flow_cache_flush_tasklet(unsigned long data)
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complete(&info->completion);
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}
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static void flow_cache_flush_per_cpu(void *) __attribute__((__unused__));
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static void flow_cache_flush_per_cpu(void *data)
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{
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struct flow_flush_info *info = data;
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@ -280,8 +282,7 @@ static void flow_cache_flush_per_cpu(void *data)
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struct tasklet_struct *tasklet;
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cpu = smp_processor_id();
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tasklet = flow_flush_tasklet(cpu);
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tasklet = &per_cpu_ptr(info->cache->percpu, cpu)->flush_tasklet;
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tasklet->data = (unsigned long)info;
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tasklet_schedule(tasklet);
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}
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@ -294,6 +295,7 @@ void flow_cache_flush(void)
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/* Don't want cpus going down or up during this. */
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get_online_cpus();
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mutex_lock(&flow_flush_sem);
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info.cache = &flow_cache_global;
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atomic_set(&info.cpuleft, num_online_cpus());
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init_completion(&info.completion);
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@ -307,62 +309,75 @@ void flow_cache_flush(void)
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put_online_cpus();
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}
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static void __init flow_cache_cpu_prepare(int cpu)
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static void __init flow_cache_cpu_prepare(struct flow_cache *fc,
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struct flow_cache_percpu *fcp)
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{
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struct tasklet_struct *tasklet;
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unsigned long order;
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fcp->hash_table = (struct flow_cache_entry **)
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__get_free_pages(GFP_KERNEL|__GFP_ZERO, fc->order);
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if (!fcp->hash_table)
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panic("NET: failed to allocate flow cache order %lu\n", fc->order);
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for (order = 0;
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(PAGE_SIZE << order) <
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(sizeof(struct flow_cache_entry *)*flow_hash_size);
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order++)
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/* NOTHING */;
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flow_table(cpu) = (struct flow_cache_entry **)
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__get_free_pages(GFP_KERNEL|__GFP_ZERO, order);
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if (!flow_table(cpu))
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panic("NET: failed to allocate flow cache order %lu\n", order);
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flow_hash_rnd_recalc(cpu) = 1;
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flow_count(cpu) = 0;
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tasklet = flow_flush_tasklet(cpu);
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tasklet_init(tasklet, flow_cache_flush_tasklet, 0);
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fcp->hash_rnd_recalc = 1;
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fcp->hash_count = 0;
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tasklet_init(&fcp->flush_tasklet, flow_cache_flush_tasklet, 0);
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}
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static int flow_cache_cpu(struct notifier_block *nfb,
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unsigned long action,
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void *hcpu)
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{
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struct flow_cache *fc = container_of(nfb, struct flow_cache, hotcpu_notifier);
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int cpu = (unsigned long) hcpu;
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struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, cpu);
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if (action == CPU_DEAD || action == CPU_DEAD_FROZEN)
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__flow_cache_shrink((unsigned long)hcpu, 0);
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__flow_cache_shrink(fc, fcp, 0);
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return NOTIFY_OK;
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}
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static int __init flow_cache_init(void)
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static int flow_cache_init(struct flow_cache *fc)
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{
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unsigned long order;
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int i;
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flow_cachep = kmem_cache_create("flow_cache",
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sizeof(struct flow_cache_entry),
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0, SLAB_PANIC,
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NULL);
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flow_hash_shift = 10;
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flow_lwm = 2 * flow_hash_size;
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flow_hwm = 4 * flow_hash_size;
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fc->hash_shift = 10;
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fc->low_watermark = 2 * flow_cache_hash_size(fc);
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fc->high_watermark = 4 * flow_cache_hash_size(fc);
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setup_timer(&flow_hash_rnd_timer, flow_cache_new_hashrnd, 0);
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flow_hash_rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD;
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add_timer(&flow_hash_rnd_timer);
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for (order = 0;
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(PAGE_SIZE << order) <
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(sizeof(struct flow_cache_entry *)*flow_cache_hash_size(fc));
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order++)
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/* NOTHING */;
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fc->order = order;
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fc->percpu = alloc_percpu(struct flow_cache_percpu);
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setup_timer(&fc->rnd_timer, flow_cache_new_hashrnd,
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(unsigned long) fc);
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fc->rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD;
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add_timer(&fc->rnd_timer);
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for_each_possible_cpu(i)
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flow_cache_cpu_prepare(i);
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flow_cache_cpu_prepare(fc, per_cpu_ptr(fc->percpu, i));
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fc->hotcpu_notifier = (struct notifier_block){
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.notifier_call = flow_cache_cpu,
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};
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register_hotcpu_notifier(&fc->hotcpu_notifier);
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hotcpu_notifier(flow_cache_cpu, 0);
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return 0;
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}
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module_init(flow_cache_init);
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static int __init flow_cache_init_global(void)
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{
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flow_cachep = kmem_cache_create("flow_cache",
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sizeof(struct flow_cache_entry),
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0, SLAB_PANIC, NULL);
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return flow_cache_init(&flow_cache_global);
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}
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module_init(flow_cache_init_global);
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EXPORT_SYMBOL(flow_cache_genid);
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EXPORT_SYMBOL(flow_cache_lookup);
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