Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d52d3997 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by David S. Miller
Browse files

ipv6: Create percpu rt6_info 



After the patch
'ipv6: Only create RTF_CACHE routes after encountering pmtu exception',
we need to compensate the performance hit (bouncing dst->__refcnt).

Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 83a09abd

include/net/ip6_fib.h

+2 −1
Original line number Diff line number Diff line
@@ -124,6 +124,7 @@ struct rt6_info { 
	struct uncached_list		*rt6i_uncached_list;



	struct inet6_dev		*rt6i_idev;

	struct rt6_info * __percpu	*rt6i_pcpu;



	u32				rt6i_metric;

	u32				rt6i_pmtu;
@@ -164,7 +165,7 @@ static inline void rt6_update_expires(struct rt6_info *rt0, int timeout) 


static inline u32 rt6_get_cookie(const struct rt6_info *rt)

{

	if (unlikely(rt->dst.flags & DST_NOCACHE))

	if (rt->rt6i_flags & RTF_PCPU || unlikely(rt->dst.flags & DST_NOCACHE))

		rt = (struct rt6_info *)(rt->dst.from);



	return rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;

include/uapi/linux/ipv6_route.h

+1 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
#define RTF_PREF(pref)	((pref) << 27)

#define RTF_PREF_MASK	0x18000000



#define RTF_PCPU	0x40000000

#define RTF_LOCAL	0x80000000

net/ipv6/ip6_fib.c

+23 −1
Original line number Diff line number Diff line
@@ -154,11 +154,33 @@ static void node_free(struct fib6_node *fn) 
	kmem_cache_free(fib6_node_kmem, fn);

}



static void rt6_free_pcpu(struct rt6_info *non_pcpu_rt)

{

	int cpu;



	if (!non_pcpu_rt->rt6i_pcpu)

		return;



	for_each_possible_cpu(cpu) {

		struct rt6_info **ppcpu_rt;

		struct rt6_info *pcpu_rt;



		ppcpu_rt = per_cpu_ptr(non_pcpu_rt->rt6i_pcpu, cpu);

		pcpu_rt = *ppcpu_rt;

		if (pcpu_rt) {

			dst_free(&pcpu_rt->dst);

			*ppcpu_rt = NULL;

		}

	}

}



static void rt6_release(struct rt6_info *rt)

{

	if (atomic_dec_and_test(&rt->rt6i_ref))

	if (atomic_dec_and_test(&rt->rt6i_ref)) {

		rt6_free_pcpu(rt);

		dst_free(&rt->dst);

	}

}



static void fib6_link_table(struct net *net, struct fib6_table *tb)

{

net/ipv6/route.c

+116 −16
Original line number Diff line number Diff line
@@ -165,11 +165,18 @@ static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev) 
	}

}



static u32 *rt6_pcpu_cow_metrics(struct rt6_info *rt)

{

	return dst_metrics_write_ptr(rt->dst.from);

}



static u32 *ipv6_cow_metrics(struct dst_entry *dst, unsigned long old)

{

	struct rt6_info *rt = (struct rt6_info *)dst;



	if (rt->rt6i_flags & RTF_CACHE)

	if (rt->rt6i_flags & RTF_PCPU)

		return rt6_pcpu_cow_metrics(rt);

	else if (rt->rt6i_flags & RTF_CACHE)

		return NULL;

	else

		return dst_cow_metrics_generic(dst, old);
@@ -309,7 +316,7 @@ static const struct rt6_info ip6_blk_hole_entry_template = { 
#endif



/* allocate dst with ip6_dst_ops */

static inline struct rt6_info *ip6_dst_alloc(struct net *net,

static struct rt6_info *__ip6_dst_alloc(struct net *net,

					struct net_device *dev,

					int flags,

					struct fib6_table *table)
@@ -327,6 +334,34 @@ static inline struct rt6_info *ip6_dst_alloc(struct net *net, 
	return rt;

}



static struct rt6_info *ip6_dst_alloc(struct net *net,

				      struct net_device *dev,

				      int flags,

				      struct fib6_table *table)

{

	struct rt6_info *rt = __ip6_dst_alloc(net, dev, flags, table);



	if (rt) {

		rt->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, GFP_ATOMIC);

		if (rt->rt6i_pcpu) {

			int cpu;



			for_each_possible_cpu(cpu) {

				struct rt6_info **p;



				p = per_cpu_ptr(rt->rt6i_pcpu, cpu);

				/* no one shares rt */

				*p =  NULL;

			}

		} else {

			dst_destroy((struct dst_entry *)rt);

			return NULL;

		}

	}



	return rt;

}



static void ip6_dst_destroy(struct dst_entry *dst)

{

	struct rt6_info *rt = (struct rt6_info *)dst;
@@ -335,6 +370,9 @@ static void ip6_dst_destroy(struct dst_entry *dst) 


	dst_destroy_metrics_generic(dst);



	if (rt->rt6i_pcpu)

		free_percpu(rt->rt6i_pcpu);



	rt6_uncached_list_del(rt);



	idev = rt->rt6i_idev;
@@ -912,10 +950,10 @@ static struct rt6_info *ip6_rt_cache_alloc(struct rt6_info *ort, 
	 *	Clone the route.

	 */



	if (ort->rt6i_flags & RTF_CACHE)

	if (ort->rt6i_flags & (RTF_CACHE | RTF_PCPU))

		ort = (struct rt6_info *)ort->dst.from;



	rt = ip6_dst_alloc(dev_net(ort->dst.dev), ort->dst.dev,

	rt = __ip6_dst_alloc(dev_net(ort->dst.dev), ort->dst.dev,

			     0, ort->rt6i_table);



	if (!rt)
@@ -943,6 +981,54 @@ static struct rt6_info *ip6_rt_cache_alloc(struct rt6_info *ort, 
	return rt;

}



static struct rt6_info *ip6_rt_pcpu_alloc(struct rt6_info *rt)

{

	struct rt6_info *pcpu_rt;



	pcpu_rt = __ip6_dst_alloc(dev_net(rt->dst.dev),

				  rt->dst.dev, rt->dst.flags,

				  rt->rt6i_table);



	if (!pcpu_rt)

		return NULL;

	ip6_rt_copy_init(pcpu_rt, rt);

	pcpu_rt->rt6i_protocol = rt->rt6i_protocol;

	pcpu_rt->rt6i_flags |= RTF_PCPU;

	return pcpu_rt;

}



/* It should be called with read_lock_bh(&tb6_lock) acquired */

static struct rt6_info *rt6_get_pcpu_route(struct rt6_info *rt)

{

	struct rt6_info *pcpu_rt, *prev, **p;



	p = this_cpu_ptr(rt->rt6i_pcpu);

	pcpu_rt = *p;



	if (pcpu_rt)

		goto done;



	pcpu_rt = ip6_rt_pcpu_alloc(rt);

	if (!pcpu_rt) {

		struct net *net = dev_net(rt->dst.dev);



		pcpu_rt = net->ipv6.ip6_null_entry;

		goto done;

	}



	prev = cmpxchg(p, NULL, pcpu_rt);

	if (prev) {

		/* If someone did it before us, return prev instead */

		dst_destroy(&pcpu_rt->dst);

		pcpu_rt = prev;

	}



done:

	dst_hold(&pcpu_rt->dst);

	rt6_dst_from_metrics_check(pcpu_rt);

	return pcpu_rt;

}



static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, int oif,

				      struct flowi6 *fl6, int flags)

{
@@ -975,11 +1061,13 @@ static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, 
		}

	}





	if (rt == net->ipv6.ip6_null_entry || (rt->rt6i_flags & RTF_CACHE)) {

		dst_use(&rt->dst, jiffies);

		read_unlock_bh(&table->tb6_lock);



	if (rt == net->ipv6.ip6_null_entry || (rt->rt6i_flags & RTF_CACHE)) {

		goto done;

		rt6_dst_from_metrics_check(rt);

		return rt;

	} else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&

			    !(rt->rt6i_flags & RTF_GATEWAY))) {

		/* Create a RTF_CACHE clone which will not be
@@ -990,6 +1078,9 @@ static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, 


		struct rt6_info *uncached_rt;



		dst_use(&rt->dst, jiffies);

		read_unlock_bh(&table->tb6_lock);



		uncached_rt = ip6_rt_cache_alloc(rt, &fl6->daddr, NULL);

		dst_release(&rt->dst);
@@ -997,13 +1088,22 @@ static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, 
			rt6_uncached_list_add(uncached_rt);

		else

			uncached_rt = net->ipv6.ip6_null_entry;



		dst_hold(&uncached_rt->dst);

		return uncached_rt;

	}



done:

	rt6_dst_from_metrics_check(rt);

	return rt;

	} else {

		/* Get a percpu copy */



		struct rt6_info *pcpu_rt;



		rt->dst.lastuse = jiffies;

		rt->dst.__use++;

		pcpu_rt = rt6_get_pcpu_route(rt);

		read_unlock_bh(&table->tb6_lock);



		return pcpu_rt;

	}

}



static struct rt6_info *ip6_pol_route_input(struct net *net, struct fib6_table *table,
@@ -1147,7 +1247,7 @@ static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie) 


	rt6_dst_from_metrics_check(rt);



	if (unlikely(dst->flags & DST_NOCACHE))

	if ((rt->rt6i_flags & RTF_PCPU) || unlikely(dst->flags & DST_NOCACHE))

		return rt6_dst_from_check(rt, cookie);

	else

		return rt6_check(rt, cookie);