From d7997fe1f4584da12e9c29fb682c18e9bdc13b73 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Timo=20Ter=C3=A4s?= Date: Wed, 31 Mar 2010 00:17:06 +0000 Subject: [PATCH] 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 Acked-by: Herbert Xu Signed-off-by: David S. Miller --- net/core/flow.c | 221 ++++++++++++++++++++++++++---------------------- 1 file changed, 118 insertions(+), 103 deletions(-) diff --git a/net/core/flow.c b/net/core/flow.c index 96015871ecea..1d27ca6b421d 100644 --- a/net/core/flow.c +++ b/net/core/flow.c @@ -35,104 +35,105 @@ struct flow_cache_entry { atomic_t *object_ref; }; -atomic_t flow_cache_genid = ATOMIC_INIT(0); - -static u32 flow_hash_shift; -#define flow_hash_size (1 << flow_hash_shift) -static DEFINE_PER_CPU(struct flow_cache_entry **, flow_tables) = { NULL }; - -#define flow_table(cpu) (per_cpu(flow_tables, cpu)) - -static struct kmem_cache *flow_cachep __read_mostly; - -static int flow_lwm, flow_hwm; - -struct flow_percpu_info { - int hash_rnd_recalc; - u32 hash_rnd; - int count; +struct flow_cache_percpu { + struct flow_cache_entry ** hash_table; + int hash_count; + u32 hash_rnd; + int hash_rnd_recalc; + struct tasklet_struct flush_tasklet; }; -static DEFINE_PER_CPU(struct flow_percpu_info, flow_hash_info) = { 0 }; - -#define flow_hash_rnd_recalc(cpu) \ - (per_cpu(flow_hash_info, cpu).hash_rnd_recalc) -#define flow_hash_rnd(cpu) \ - (per_cpu(flow_hash_info, cpu).hash_rnd) -#define flow_count(cpu) \ - (per_cpu(flow_hash_info, cpu).count) - -static struct timer_list flow_hash_rnd_timer; - -#define FLOW_HASH_RND_PERIOD (10 * 60 * HZ) struct flow_flush_info { - atomic_t cpuleft; - struct completion completion; + struct flow_cache * cache; + atomic_t cpuleft; + struct completion completion; }; -static DEFINE_PER_CPU(struct tasklet_struct, flow_flush_tasklets) = { NULL }; -#define flow_flush_tasklet(cpu) (&per_cpu(flow_flush_tasklets, cpu)) +struct flow_cache { + u32 hash_shift; + unsigned long order; + struct flow_cache_percpu * percpu; + struct notifier_block hotcpu_notifier; + int low_watermark; + int high_watermark; + struct timer_list rnd_timer; +}; + +atomic_t flow_cache_genid = ATOMIC_INIT(0); +static struct flow_cache flow_cache_global; +static struct kmem_cache *flow_cachep; + +#define flow_cache_hash_size(cache) (1 << (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) - flow_hash_rnd_recalc(i) = 1; + per_cpu_ptr(fc->percpu, i)->hash_rnd_recalc = 1; - flow_hash_rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD; - add_timer(&flow_hash_rnd_timer); + fc->rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD; + add_timer(&fc->rnd_timer); } -static void flow_entry_kill(int cpu, struct flow_cache_entry *fle) +static void flow_entry_kill(struct flow_cache *fc, + struct flow_cache_percpu *fcp, + struct flow_cache_entry *fle) { if (fle->object) atomic_dec(fle->object_ref); kmem_cache_free(flow_cachep, fle); - flow_count(cpu)--; + fcp->hash_count--; } -static void __flow_cache_shrink(int cpu, int shrink_to) +static void __flow_cache_shrink(struct flow_cache *fc, + struct flow_cache_percpu *fcp, + int shrink_to) { struct flow_cache_entry *fle, **flp; int i; - for (i = 0; i < flow_hash_size; i++) { + for (i = 0; i < flow_cache_hash_size(fc); i++) { int k = 0; - flp = &flow_table(cpu)[i]; + flp = &fcp->hash_table[i]; while ((fle = *flp) != NULL && k < shrink_to) { k++; flp = &fle->next; } while ((fle = *flp) != NULL) { *flp = fle->next; - flow_entry_kill(cpu, fle); + flow_entry_kill(fc, fcp, fle); } } } -static void flow_cache_shrink(int cpu) +static void flow_cache_shrink(struct flow_cache *fc, + struct flow_cache_percpu *fcp) { - int shrink_to = flow_lwm / flow_hash_size; + int shrink_to = fc->low_watermark / flow_cache_hash_size(fc); - __flow_cache_shrink(cpu, shrink_to); + __flow_cache_shrink(fc, fcp, shrink_to); } -static void flow_new_hash_rnd(int cpu) +static void flow_new_hash_rnd(struct flow_cache *fc, + struct flow_cache_percpu *fcp) { - get_random_bytes(&flow_hash_rnd(cpu), sizeof(u32)); - flow_hash_rnd_recalc(cpu) = 0; - - __flow_cache_shrink(cpu, 0); + 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 flowi *key, int cpu) +static u32 flow_hash_code(struct flow_cache *fc, + struct flow_cache_percpu *fcp, + struct flowi *key) { u32 *k = (u32 *) key; - return (jhash2(k, (sizeof(*key) / sizeof(u32)), flow_hash_rnd(cpu)) & - (flow_hash_size - 1)); + return (jhash2(k, (sizeof(*key) / sizeof(u32)), fcp->hash_rnd) + & (flow_cache_hash_size(fc) - 1)); } #if (BITS_PER_LONG == 64) @@ -168,24 +169,25 @@ static int flow_key_compare(struct flowi *key1, struct flowi *key2) void *flow_cache_lookup(struct net *net, struct flowi *key, u16 family, u8 dir, flow_resolve_t resolver) { + struct flow_cache *fc = &flow_cache_global; + struct flow_cache_percpu *fcp; struct flow_cache_entry *fle, **head; unsigned int hash; - int cpu; local_bh_disable(); - cpu = smp_processor_id(); + fcp = per_cpu_ptr(fc->percpu, smp_processor_id()); fle = NULL; /* Packet really early in init? Making flow_cache_init a * pre-smp initcall would solve this. --RR */ - if (!flow_table(cpu)) + if (!fcp->hash_table) goto nocache; - if (flow_hash_rnd_recalc(cpu)) - flow_new_hash_rnd(cpu); - hash = flow_hash_code(key, cpu); + if (fcp->hash_rnd_recalc) + flow_new_hash_rnd(fc, fcp); + hash = flow_hash_code(fc, fcp, key); - head = &flow_table(cpu)[hash]; + head = &fcp->hash_table[hash]; for (fle = *head; fle; fle = fle->next) { if (fle->family == family && fle->dir == dir && @@ -204,8 +206,8 @@ void *flow_cache_lookup(struct net *net, struct flowi *key, u16 family, u8 dir, } if (!fle) { - if (flow_count(cpu) > flow_hwm) - flow_cache_shrink(cpu); + if (fcp->hash_count > fc->high_watermark) + flow_cache_shrink(fc, fcp); fle = kmem_cache_alloc(flow_cachep, GFP_ATOMIC); if (fle) { @@ -215,7 +217,7 @@ void *flow_cache_lookup(struct net *net, struct flowi *key, u16 family, u8 dir, fle->dir = dir; memcpy(&fle->key, key, sizeof(*key)); fle->object = NULL; - flow_count(cpu)++; + fcp->hash_count++; } } @@ -249,14 +251,15 @@ void *flow_cache_lookup(struct net *net, struct flowi *key, u16 family, u8 dir, 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; int i; - int cpu; - cpu = smp_processor_id(); - for (i = 0; i < flow_hash_size; i++) { + fcp = per_cpu_ptr(fc->percpu, smp_processor_id()); + for (i = 0; i < flow_cache_hash_size(fc); i++) { struct flow_cache_entry *fle; - fle = flow_table(cpu)[i]; + fle = fcp->hash_table[i]; for (; fle; fle = fle->next) { unsigned genid = atomic_read(&flow_cache_genid); @@ -272,7 +275,6 @@ static void flow_cache_flush_tasklet(unsigned long data) complete(&info->completion); } -static void flow_cache_flush_per_cpu(void *) __attribute__((__unused__)); static void flow_cache_flush_per_cpu(void *data) { struct flow_flush_info *info = data; @@ -280,8 +282,7 @@ static void flow_cache_flush_per_cpu(void *data) struct tasklet_struct *tasklet; cpu = smp_processor_id(); - - tasklet = flow_flush_tasklet(cpu); + tasklet = &per_cpu_ptr(info->cache->percpu, cpu)->flush_tasklet; tasklet->data = (unsigned long)info; tasklet_schedule(tasklet); } @@ -294,6 +295,7 @@ void flow_cache_flush(void) /* Don't want cpus going down or up during this. */ get_online_cpus(); mutex_lock(&flow_flush_sem); + info.cache = &flow_cache_global; atomic_set(&info.cpuleft, num_online_cpus()); init_completion(&info.completion); @@ -307,62 +309,75 @@ void flow_cache_flush(void) put_online_cpus(); } -static void __init flow_cache_cpu_prepare(int cpu) +static void __init flow_cache_cpu_prepare(struct flow_cache *fc, + struct flow_cache_percpu *fcp) { - struct tasklet_struct *tasklet; - unsigned long order; + fcp->hash_table = (struct flow_cache_entry **) + __get_free_pages(GFP_KERNEL|__GFP_ZERO, fc->order); + if (!fcp->hash_table) + panic("NET: failed to allocate flow cache order %lu\n", fc->order); - for (order = 0; - (PAGE_SIZE << order) < - (sizeof(struct flow_cache_entry *)*flow_hash_size); - order++) - /* NOTHING */; - - flow_table(cpu) = (struct flow_cache_entry **) - __get_free_pages(GFP_KERNEL|__GFP_ZERO, order); - if (!flow_table(cpu)) - panic("NET: failed to allocate flow cache order %lu\n", order); - - flow_hash_rnd_recalc(cpu) = 1; - flow_count(cpu) = 0; - - tasklet = flow_flush_tasklet(cpu); - tasklet_init(tasklet, flow_cache_flush_tasklet, 0); + fcp->hash_rnd_recalc = 1; + fcp->hash_count = 0; + tasklet_init(&fcp->flush_tasklet, flow_cache_flush_tasklet, 0); } static int flow_cache_cpu(struct notifier_block *nfb, unsigned long action, void *hcpu) { + struct flow_cache *fc = container_of(nfb, struct flow_cache, hotcpu_notifier); + int cpu = (unsigned long) hcpu; + struct flow_cache_percpu *fcp = per_cpu_ptr(fc->percpu, cpu); + if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) - __flow_cache_shrink((unsigned long)hcpu, 0); + __flow_cache_shrink(fc, fcp, 0); return NOTIFY_OK; } -static int __init flow_cache_init(void) +static int flow_cache_init(struct flow_cache *fc) { + unsigned long order; int i; - flow_cachep = kmem_cache_create("flow_cache", - sizeof(struct flow_cache_entry), - 0, SLAB_PANIC, - NULL); - flow_hash_shift = 10; - flow_lwm = 2 * flow_hash_size; - flow_hwm = 4 * flow_hash_size; + fc->hash_shift = 10; + fc->low_watermark = 2 * flow_cache_hash_size(fc); + fc->high_watermark = 4 * flow_cache_hash_size(fc); - setup_timer(&flow_hash_rnd_timer, flow_cache_new_hashrnd, 0); - flow_hash_rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD; - add_timer(&flow_hash_rnd_timer); + for (order = 0; + (PAGE_SIZE << order) < + (sizeof(struct flow_cache_entry *)*flow_cache_hash_size(fc)); + order++) + /* NOTHING */; + fc->order = order; + fc->percpu = alloc_percpu(struct flow_cache_percpu); + + 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); for_each_possible_cpu(i) - flow_cache_cpu_prepare(i); + flow_cache_cpu_prepare(fc, per_cpu_ptr(fc->percpu, i)); + + fc->hotcpu_notifier = (struct notifier_block){ + .notifier_call = flow_cache_cpu, + }; + register_hotcpu_notifier(&fc->hotcpu_notifier); - hotcpu_notifier(flow_cache_cpu, 0); return 0; } -module_init(flow_cache_init); +static int __init flow_cache_init_global(void) +{ + flow_cachep = kmem_cache_create("flow_cache", + sizeof(struct flow_cache_entry), + 0, SLAB_PANIC, NULL); + + return flow_cache_init(&flow_cache_global); +} + +module_init(flow_cache_init_global); EXPORT_SYMBOL(flow_cache_genid); EXPORT_SYMBOL(flow_cache_lookup);