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Commit d7997fe1 authored by Timo Teräs's avatar Timo Teräs Committed by David S. Miller
Browse files

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: default avatarTimo Teras <timo.teras@iki.fi>
Acked-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ea2dea9d

net/core/flow.c

+119 −104
Original line number Original line Diff line number Diff line
@@ -35,104 +35,105 @@ struct flow_cache_entry { 
	atomic_t		*object_ref;

	atomic_t		*object_ref;

};

};





atomic_t flow_cache_genid = ATOMIC_INIT(0);

struct flow_cache_percpu {



	struct flow_cache_entry **	hash_table;

static u32 flow_hash_shift;

	int				hash_count;

#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;

	u32				hash_rnd;

	int count;

	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 {

struct flow_flush_info {

	struct flow_cache *		cache;

	atomic_t			cpuleft;

	atomic_t			cpuleft;

	struct completion		completion;

	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)

static void flow_cache_new_hashrnd(unsigned long arg)

{

{

	struct flow_cache *fc = (void *) arg;

	int i;

	int i;





	for_each_possible_cpu(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;

	fc->rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD;

	add_timer(&flow_hash_rnd_timer);

	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)

	if (fle->object)

		atomic_dec(fle->object_ref);

		atomic_dec(fle->object_ref);

	kmem_cache_free(flow_cachep, fle);

	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;

	struct flow_cache_entry *fle, **flp;

	int i;

	int i;





	for (i = 0; i < flow_hash_size; i++) {

	for (i = 0; i < flow_cache_hash_size(fc); i++) {

		int k = 0;

		int k = 0;





		flp = &flow_table(cpu)[i];

		flp = &fcp->hash_table[i];

		while ((fle = *flp) != NULL && k < shrink_to) {

		while ((fle = *flp) != NULL && k < shrink_to) {

			k++;

			k++;

			flp = &fle->next;

			flp = &fle->next;

		}

		}

		while ((fle = *flp) != NULL) {

		while ((fle = *flp) != NULL) {

			*flp = fle->next;

			*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));

	get_random_bytes(&fcp->hash_rnd, sizeof(u32));

	flow_hash_rnd_recalc(cpu) = 0;

	fcp->hash_rnd_recalc = 0;



	__flow_cache_shrink(fc, fcp, 0);

	__flow_cache_shrink(cpu, 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;

	u32 *k = (u32 *) key;





	return (jhash2(k, (sizeof(*key) / sizeof(u32)), flow_hash_rnd(cpu)) &

	return (jhash2(k, (sizeof(*key) / sizeof(u32)), fcp->hash_rnd)

		(flow_hash_size - 1));

		& (flow_cache_hash_size(fc) - 1));

}

}





#if (BITS_PER_LONG == 64)

#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,

void *flow_cache_lookup(struct net *net, struct flowi *key, u16 family, u8 dir,

			flow_resolve_t resolver)

			flow_resolve_t resolver)

{

{

	struct flow_cache *fc = &flow_cache_global;

	struct flow_cache_percpu *fcp;

	struct flow_cache_entry *fle, **head;

	struct flow_cache_entry *fle, **head;

	unsigned int hash;

	unsigned int hash;

	int cpu;





	local_bh_disable();

	local_bh_disable();

	cpu = smp_processor_id();

	fcp = per_cpu_ptr(fc->percpu, smp_processor_id());





	fle = NULL;

	fle = NULL;

	/* Packet really early in init?  Making flow_cache_init a

	/* Packet really early in init?  Making flow_cache_init a

	 * pre-smp initcall would solve this.  --RR */

	 * pre-smp initcall would solve this.  --RR */

	if (!flow_table(cpu))

	if (!fcp->hash_table)

		goto nocache;

		goto nocache;





	if (flow_hash_rnd_recalc(cpu))

	if (fcp->hash_rnd_recalc)

		flow_new_hash_rnd(cpu);

		flow_new_hash_rnd(fc, fcp);

	hash = flow_hash_code(key, cpu);

	hash = flow_hash_code(fc, fcp, key);





	head = &flow_table(cpu)[hash];

	head = &fcp->hash_table[hash];

	for (fle = *head; fle; fle = fle->next) {

	for (fle = *head; fle; fle = fle->next) {

		if (fle->family == family &&

		if (fle->family == family &&

		    fle->dir == dir &&

		    fle->dir == dir &&
@@ -204,8 +206,8 @@ void *flow_cache_lookup(struct net *net, struct flowi *key, u16 family, u8 dir, 
	}

	}





	if (!fle) {

	if (!fle) {

		if (flow_count(cpu) > flow_hwm)

		if (fcp->hash_count > fc->high_watermark)

			flow_cache_shrink(cpu);

			flow_cache_shrink(fc, fcp);





		fle = kmem_cache_alloc(flow_cachep, GFP_ATOMIC);

		fle = kmem_cache_alloc(flow_cachep, GFP_ATOMIC);

		if (fle) {

		if (fle) {
@@ -215,7 +217,7 @@ void *flow_cache_lookup(struct net *net, struct flowi *key, u16 family, u8 dir, 
			fle->dir = dir;

			fle->dir = dir;

			memcpy(&fle->key, key, sizeof(*key));

			memcpy(&fle->key, key, sizeof(*key));

			fle->object = NULL;

			fle->object = NULL;

			flow_count(cpu)++;

			fcp->hash_count++;

		}

		}

	}

	}
@@ -249,14 +251,15 @@ nocache: 
static void flow_cache_flush_tasklet(unsigned long data)

static void flow_cache_flush_tasklet(unsigned long data)

{

{

	struct flow_flush_info *info = (void *)data;

	struct flow_flush_info *info = (void *)data;

	struct flow_cache *fc = info->cache;

	struct flow_cache_percpu *fcp;

	int i;

	int i;

	int cpu;





	cpu = smp_processor_id();

	fcp = per_cpu_ptr(fc->percpu, smp_processor_id());

	for (i = 0; i < flow_hash_size; i++) {

	for (i = 0; i < flow_cache_hash_size(fc); i++) {

		struct flow_cache_entry *fle;

		struct flow_cache_entry *fle;





		fle = flow_table(cpu)[i];

		fle = fcp->hash_table[i];

		for (; fle; fle = fle->next) {

		for (; fle; fle = fle->next) {

			unsigned genid = atomic_read(&flow_cache_genid);

			unsigned genid = atomic_read(&flow_cache_genid);
@@ -272,7 +275,6 @@ static void flow_cache_flush_tasklet(unsigned long data) 
		complete(&info->completion);

		complete(&info->completion);

}

}





static void flow_cache_flush_per_cpu(void *) __attribute__((__unused__));

static void flow_cache_flush_per_cpu(void *data)

static void flow_cache_flush_per_cpu(void *data)

{

{

	struct flow_flush_info *info = data;

	struct flow_flush_info *info = data;
@@ -280,8 +282,7 @@ static void flow_cache_flush_per_cpu(void *data) 
	struct tasklet_struct *tasklet;

	struct tasklet_struct *tasklet;





	cpu = smp_processor_id();

	cpu = smp_processor_id();



	tasklet = &per_cpu_ptr(info->cache->percpu, cpu)->flush_tasklet;

	tasklet = flow_flush_tasklet(cpu);

	tasklet->data = (unsigned long)info;

	tasklet->data = (unsigned long)info;

	tasklet_schedule(tasklet);

	tasklet_schedule(tasklet);

}

}
@@ -294,6 +295,7 @@ void flow_cache_flush(void) 
	/* Don't want cpus going down or up during this. */

	/* Don't want cpus going down or up during this. */

	get_online_cpus();

	get_online_cpus();

	mutex_lock(&flow_flush_sem);

	mutex_lock(&flow_flush_sem);

	info.cache = &flow_cache_global;

	atomic_set(&info.cpuleft, num_online_cpus());

	atomic_set(&info.cpuleft, num_online_cpus());

	init_completion(&info.completion);

	init_completion(&info.completion);
@@ -307,62 +309,75 @@ void flow_cache_flush(void) 
	put_online_cpus();

	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;

	fcp->hash_table = (struct flow_cache_entry **)

	unsigned long order;

		__get_free_pages(GFP_KERNEL|__GFP_ZERO, fc->order);



	if (!fcp->hash_table)

	for (order = 0;

		panic("NET: failed to allocate flow cache order %lu\n", fc->order);

	     (PAGE_SIZE << order) <



		     (sizeof(struct flow_cache_entry *)*flow_hash_size);

	fcp->hash_rnd_recalc = 1;

	     order++)

	fcp->hash_count = 0;

		/* NOTHING */;

	tasklet_init(&fcp->flush_tasklet, flow_cache_flush_tasklet, 0);



	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);

}

}





static int flow_cache_cpu(struct notifier_block *nfb,

static int flow_cache_cpu(struct notifier_block *nfb,

			  unsigned long action,

			  unsigned long action,

			  void *hcpu)

			  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)

	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN)

		__flow_cache_shrink((unsigned long)hcpu, 0);

		__flow_cache_shrink(fc, fcp, 0);

	return NOTIFY_OK;

	return NOTIFY_OK;

}

}





static int __init flow_cache_init(void)

static int flow_cache_init(struct flow_cache *fc)

{

{

	unsigned long order;

	int i;

	int i;





	flow_cachep = kmem_cache_create("flow_cache",

	fc->hash_shift = 10;

					sizeof(struct flow_cache_entry),

	fc->low_watermark = 2 * flow_cache_hash_size(fc);

					0, SLAB_PANIC,

	fc->high_watermark = 4 * flow_cache_hash_size(fc);

					NULL);

	flow_hash_shift = 10;

	flow_lwm = 2 * flow_hash_size;

	flow_hwm = 4 * flow_hash_size;





	setup_timer(&flow_hash_rnd_timer, flow_cache_new_hashrnd, 0);

	for (order = 0;

	flow_hash_rnd_timer.expires = jiffies + FLOW_HASH_RND_PERIOD;

	     (PAGE_SIZE << order) <

	add_timer(&flow_hash_rnd_timer);

		     (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)

	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;

	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_genid);

EXPORT_SYMBOL(flow_cache_lookup);
 
EXPORT_SYMBOL(flow_cache_lookup);