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: Martin 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: David S. Miller <davem@davemloft.net>
This commit is contained in:
Martin KaFai Lau
David S. Miller
Родитель
83a09abd1a
Коммит
d52d3997f8
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@ -124,6 +124,7 @@ struct rt6_info {
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struct uncached_list *rt6i_uncached_list;
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struct inet6_dev *rt6i_idev;
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struct rt6_info * __percpu *rt6i_pcpu;
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u32 rt6i_metric;
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u32 rt6i_pmtu;
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@ -164,7 +165,7 @@ static inline void rt6_update_expires(struct rt6_info *rt0, int timeout)
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static inline u32 rt6_get_cookie(const struct rt6_info *rt)
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{
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if (unlikely(rt->dst.flags & DST_NOCACHE))
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if (rt->rt6i_flags & RTF_PCPU || unlikely(rt->dst.flags & DST_NOCACHE))
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rt = (struct rt6_info *)(rt->dst.from);
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return rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
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@ -34,6 +34,7 @@
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#define RTF_PREF(pref) ((pref) << 27)
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#define RTF_PREF_MASK 0x18000000
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#define RTF_PCPU 0x40000000
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#define RTF_LOCAL 0x80000000
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@ -154,10 +154,32 @@ static void node_free(struct fib6_node *fn)
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kmem_cache_free(fib6_node_kmem, fn);
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}
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static void rt6_free_pcpu(struct rt6_info *non_pcpu_rt)
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{
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int cpu;
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if (!non_pcpu_rt->rt6i_pcpu)
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return;
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for_each_possible_cpu(cpu) {
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struct rt6_info **ppcpu_rt;
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struct rt6_info *pcpu_rt;
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ppcpu_rt = per_cpu_ptr(non_pcpu_rt->rt6i_pcpu, cpu);
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pcpu_rt = *ppcpu_rt;
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if (pcpu_rt) {
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dst_free(&pcpu_rt->dst);
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*ppcpu_rt = NULL;
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}
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}
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}
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static void rt6_release(struct rt6_info *rt)
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{
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if (atomic_dec_and_test(&rt->rt6i_ref))
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if (atomic_dec_and_test(&rt->rt6i_ref)) {
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rt6_free_pcpu(rt);
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dst_free(&rt->dst);
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}
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}
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static void fib6_link_table(struct net *net, struct fib6_table *tb)
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122
net/ipv6/route.c
122
net/ipv6/route.c
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@ -165,11 +165,18 @@ static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev)
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}
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}
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static u32 *rt6_pcpu_cow_metrics(struct rt6_info *rt)
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{
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return dst_metrics_write_ptr(rt->dst.from);
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}
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static u32 *ipv6_cow_metrics(struct dst_entry *dst, unsigned long old)
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{
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struct rt6_info *rt = (struct rt6_info *)dst;
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if (rt->rt6i_flags & RTF_CACHE)
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if (rt->rt6i_flags & RTF_PCPU)
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return rt6_pcpu_cow_metrics(rt);
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else if (rt->rt6i_flags & RTF_CACHE)
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return NULL;
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else
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return dst_cow_metrics_generic(dst, old);
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@ -309,7 +316,7 @@ static const struct rt6_info ip6_blk_hole_entry_template = {
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#endif
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/* allocate dst with ip6_dst_ops */
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static inline struct rt6_info *ip6_dst_alloc(struct net *net,
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static struct rt6_info *__ip6_dst_alloc(struct net *net,
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struct net_device *dev,
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int flags,
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struct fib6_table *table)
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@ -327,6 +334,34 @@ static inline struct rt6_info *ip6_dst_alloc(struct net *net,
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return rt;
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}
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static struct rt6_info *ip6_dst_alloc(struct net *net,
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struct net_device *dev,
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int flags,
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struct fib6_table *table)
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{
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struct rt6_info *rt = __ip6_dst_alloc(net, dev, flags, table);
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if (rt) {
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rt->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, GFP_ATOMIC);
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if (rt->rt6i_pcpu) {
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int cpu;
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for_each_possible_cpu(cpu) {
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struct rt6_info **p;
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p = per_cpu_ptr(rt->rt6i_pcpu, cpu);
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/* no one shares rt */
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*p = NULL;
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}
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} else {
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dst_destroy((struct dst_entry *)rt);
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return NULL;
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}
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}
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return rt;
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}
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static void ip6_dst_destroy(struct dst_entry *dst)
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{
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struct rt6_info *rt = (struct rt6_info *)dst;
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@ -335,6 +370,9 @@ static void ip6_dst_destroy(struct dst_entry *dst)
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dst_destroy_metrics_generic(dst);
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if (rt->rt6i_pcpu)
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free_percpu(rt->rt6i_pcpu);
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rt6_uncached_list_del(rt);
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idev = rt->rt6i_idev;
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@ -912,10 +950,10 @@ static struct rt6_info *ip6_rt_cache_alloc(struct rt6_info *ort,
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* Clone the route.
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*/
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if (ort->rt6i_flags & RTF_CACHE)
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if (ort->rt6i_flags & (RTF_CACHE | RTF_PCPU))
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ort = (struct rt6_info *)ort->dst.from;
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rt = ip6_dst_alloc(dev_net(ort->dst.dev), ort->dst.dev,
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rt = __ip6_dst_alloc(dev_net(ort->dst.dev), ort->dst.dev,
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0, ort->rt6i_table);
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if (!rt)
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@ -943,6 +981,54 @@ static struct rt6_info *ip6_rt_cache_alloc(struct rt6_info *ort,
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return rt;
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}
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static struct rt6_info *ip6_rt_pcpu_alloc(struct rt6_info *rt)
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{
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struct rt6_info *pcpu_rt;
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pcpu_rt = __ip6_dst_alloc(dev_net(rt->dst.dev),
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rt->dst.dev, rt->dst.flags,
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rt->rt6i_table);
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if (!pcpu_rt)
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return NULL;
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ip6_rt_copy_init(pcpu_rt, rt);
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pcpu_rt->rt6i_protocol = rt->rt6i_protocol;
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pcpu_rt->rt6i_flags |= RTF_PCPU;
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return pcpu_rt;
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}
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/* It should be called with read_lock_bh(&tb6_lock) acquired */
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static struct rt6_info *rt6_get_pcpu_route(struct rt6_info *rt)
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{
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struct rt6_info *pcpu_rt, *prev, **p;
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p = this_cpu_ptr(rt->rt6i_pcpu);
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pcpu_rt = *p;
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if (pcpu_rt)
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goto done;
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pcpu_rt = ip6_rt_pcpu_alloc(rt);
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if (!pcpu_rt) {
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struct net *net = dev_net(rt->dst.dev);
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pcpu_rt = net->ipv6.ip6_null_entry;
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goto done;
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}
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prev = cmpxchg(p, NULL, pcpu_rt);
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if (prev) {
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/* If someone did it before us, return prev instead */
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dst_destroy(&pcpu_rt->dst);
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pcpu_rt = prev;
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}
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done:
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dst_hold(&pcpu_rt->dst);
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rt6_dst_from_metrics_check(pcpu_rt);
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return pcpu_rt;
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}
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static struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, int oif,
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struct flowi6 *fl6, int flags)
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{
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@ -975,11 +1061,13 @@ redo_rt6_select:
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}
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}
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if (rt == net->ipv6.ip6_null_entry || (rt->rt6i_flags & RTF_CACHE)) {
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dst_use(&rt->dst, jiffies);
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read_unlock_bh(&table->tb6_lock);
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if (rt == net->ipv6.ip6_null_entry || (rt->rt6i_flags & RTF_CACHE)) {
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goto done;
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rt6_dst_from_metrics_check(rt);
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return rt;
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} else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
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!(rt->rt6i_flags & RTF_GATEWAY))) {
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/* Create a RTF_CACHE clone which will not be
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@ -990,6 +1078,9 @@ redo_rt6_select:
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struct rt6_info *uncached_rt;
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dst_use(&rt->dst, jiffies);
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read_unlock_bh(&table->tb6_lock);
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uncached_rt = ip6_rt_cache_alloc(rt, &fl6->daddr, NULL);
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dst_release(&rt->dst);
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@ -997,13 +1088,22 @@ redo_rt6_select:
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rt6_uncached_list_add(uncached_rt);
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else
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uncached_rt = net->ipv6.ip6_null_entry;
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dst_hold(&uncached_rt->dst);
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return uncached_rt;
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}
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done:
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rt6_dst_from_metrics_check(rt);
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return rt;
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} else {
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/* Get a percpu copy */
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struct rt6_info *pcpu_rt;
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rt->dst.lastuse = jiffies;
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rt->dst.__use++;
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pcpu_rt = rt6_get_pcpu_route(rt);
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read_unlock_bh(&table->tb6_lock);
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return pcpu_rt;
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}
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}
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static struct rt6_info *ip6_pol_route_input(struct net *net, struct fib6_table *table,
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@ -1147,7 +1247,7 @@ static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
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rt6_dst_from_metrics_check(rt);
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if (unlikely(dst->flags & DST_NOCACHE))
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if ((rt->rt6i_flags & RTF_PCPU) || unlikely(dst->flags & DST_NOCACHE))
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return rt6_dst_from_check(rt, cookie);
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else
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return rt6_check(rt, cookie);
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