net/ipv4/tcp_memcontrol.c

   1 #include <net/tcp.h>
   2 #include <net/tcp_memcontrol.h>
   3 #include <net/sock.h>
   4 #include <net/ip.h>
   5 #include <linux/nsproxy.h>
   6 #include <linux/memcontrol.h>
   7 #include <linux/module.h>
   8
   9 static u64 tcp_cgroup_read(struct cgroup *cont, struct cftype *cft);
  10 static int tcp_cgroup_write(struct cgroup *cont, struct cftype *cft,
  11                             const char *buffer);
  12 static int tcp_cgroup_reset(struct cgroup *cont, unsigned int event);
  13
  14 static struct cftype tcp_files[] = {
  15         {
  16                 .name = "kmem.tcp.limit_in_bytes",
  17                 .write_string = tcp_cgroup_write,
  18                 .read_u64 = tcp_cgroup_read,
  19                 .private = RES_LIMIT,
  20         },
  21         {
  22                 .name = "kmem.tcp.usage_in_bytes",
  23                 .read_u64 = tcp_cgroup_read,
  24                 .private = RES_USAGE,
  25         },
  26         {
  27                 .name = "kmem.tcp.failcnt",
  28                 .private = RES_FAILCNT,
  29                 .trigger = tcp_cgroup_reset,
  30                 .read_u64 = tcp_cgroup_read,
  31         },
  32         {
  33                 .name = "kmem.tcp.max_usage_in_bytes",
  34                 .private = RES_MAX_USAGE,
  35                 .trigger = tcp_cgroup_reset,
  36                 .read_u64 = tcp_cgroup_read,
  37         },
  38 };
  39
  40 static inline struct tcp_memcontrol *tcp_from_cgproto(struct cg_proto *cg_proto)
  41 {
  42         return container_of(cg_proto, struct tcp_memcontrol, cg_proto);
  43 }
  44
  45 static void memcg_tcp_enter_memory_pressure(struct sock *sk)
  46 {
  47         if (sk->sk_cgrp->memory_pressure)
  48                 *sk->sk_cgrp->memory_pressure = 1;
  49 }
  50 EXPORT_SYMBOL(memcg_tcp_enter_memory_pressure);
  51
  52 int tcp_init_cgroup(struct cgroup *cgrp, struct cgroup_subsys *ss)
  53 {
  54         /*
  55          * The root cgroup does not use res_counters, but rather,
  56          * rely on the data already collected by the network
  57          * subsystem
  58          */
  59         struct res_counter *res_parent = NULL;
  60         struct cg_proto *cg_proto, *parent_cg;
  61         struct tcp_memcontrol *tcp;
  62         struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
  63         struct mem_cgroup *parent = parent_mem_cgroup(memcg);
  64         struct net *net = current->nsproxy->net_ns;
  65
  66         cg_proto = tcp_prot.proto_cgroup(memcg);
  67         if (!cg_proto)
  68                 goto create_files;
  69
  70         tcp = tcp_from_cgproto(cg_proto);
  71
  72         tcp->tcp_prot_mem[0] = net->ipv4.sysctl_tcp_mem[0];
  73         tcp->tcp_prot_mem[1] = net->ipv4.sysctl_tcp_mem[1];
  74         tcp->tcp_prot_mem[2] = net->ipv4.sysctl_tcp_mem[2];
  75         tcp->tcp_memory_pressure = 0;
  76
  77         parent_cg = tcp_prot.proto_cgroup(parent);
  78         if (parent_cg)
  79                 res_parent = parent_cg->memory_allocated;
  80
  81         res_counter_init(&tcp->tcp_memory_allocated, res_parent);
  82         percpu_counter_init(&tcp->tcp_sockets_allocated, 0);
  83
  84         cg_proto->enter_memory_pressure = memcg_tcp_enter_memory_pressure;
  85         cg_proto->memory_pressure = &tcp->tcp_memory_pressure;
  86         cg_proto->sysctl_mem = tcp->tcp_prot_mem;
  87         cg_proto->memory_allocated = &tcp->tcp_memory_allocated;
  88         cg_proto->sockets_allocated = &tcp->tcp_sockets_allocated;
  89         cg_proto->memcg = memcg;
  90
  91 create_files:
  92         return cgroup_add_files(cgrp, ss, tcp_files,
  93                                 ARRAY_SIZE(tcp_files));
  94 }
  95 EXPORT_SYMBOL(tcp_init_cgroup);
  96
  97 void tcp_destroy_cgroup(struct cgroup *cgrp)
  98 {
  99         struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
 100         struct cg_proto *cg_proto;
 101         struct tcp_memcontrol *tcp;
 102         u64 val;
 103
 104         cg_proto = tcp_prot.proto_cgroup(memcg);
 105         if (!cg_proto)
 106                 return;
 107
 108         tcp = tcp_from_cgproto(cg_proto);
 109         percpu_counter_destroy(&tcp->tcp_sockets_allocated);
 110
 111         val = res_counter_read_u64(&tcp->tcp_memory_allocated, RES_LIMIT);
 112
 113         if (val != RESOURCE_MAX)
 114                 static_key_slow_dec(&memcg_socket_limit_enabled);
 115 }
 116 EXPORT_SYMBOL(tcp_destroy_cgroup);
 117
 118 static int tcp_update_limit(struct mem_cgroup *memcg, u64 val)
 119 {
 120         struct net *net = current->nsproxy->net_ns;
 121         struct tcp_memcontrol *tcp;
 122         struct cg_proto *cg_proto;
 123         u64 old_lim;
 124         int i;
 125         int ret;
 126
 127         cg_proto = tcp_prot.proto_cgroup(memcg);
 128         if (!cg_proto)
 129                 return -EINVAL;
 130
 131         if (val > RESOURCE_MAX)
 132                 val = RESOURCE_MAX;
 133
 134         tcp = tcp_from_cgproto(cg_proto);
 135
 136         old_lim = res_counter_read_u64(&tcp->tcp_memory_allocated, RES_LIMIT);
 137         ret = res_counter_set_limit(&tcp->tcp_memory_allocated, val);
 138         if (ret)
 139                 return ret;
 140
 141         for (i = 0; i < 3; i++)
 142                 tcp->tcp_prot_mem[i] = min_t(long, val >> PAGE_SHIFT,
 143                                              net->ipv4.sysctl_tcp_mem[i]);
 144
 145         if (val == RESOURCE_MAX && old_lim != RESOURCE_MAX)
 146                 static_key_slow_dec(&memcg_socket_limit_enabled);
 147         else if (old_lim == RESOURCE_MAX && val != RESOURCE_MAX)
 148                 static_key_slow_inc(&memcg_socket_limit_enabled);
 149
 150         return 0;
 151 }
 152
 153 static int tcp_cgroup_write(struct cgroup *cont, struct cftype *cft,
 154                             const char *buffer)
 155 {
 156         struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
 157         unsigned long long val;
 158         int ret = 0;
 159
 160         switch (cft->private) {
 161         case RES_LIMIT:
 162                 /* see memcontrol.c */
 163                 ret = res_counter_memparse_write_strategy(buffer, &val);
 164                 if (ret)
 165                         break;
 166                 ret = tcp_update_limit(memcg, val);
 167                 break;
 168         default:
 169                 ret = -EINVAL;
 170                 break;
 171         }
 172         return ret;
 173 }
 174
 175 static u64 tcp_read_stat(struct mem_cgroup *memcg, int type, u64 default_val)
 176 {
 177         struct tcp_memcontrol *tcp;
 178         struct cg_proto *cg_proto;
 179
 180         cg_proto = tcp_prot.proto_cgroup(memcg);
 181         if (!cg_proto)
 182                 return default_val;
 183
 184         tcp = tcp_from_cgproto(cg_proto);
 185         return res_counter_read_u64(&tcp->tcp_memory_allocated, type);
 186 }
 187
 188 static u64 tcp_read_usage(struct mem_cgroup *memcg)
 189 {
 190         struct tcp_memcontrol *tcp;
 191         struct cg_proto *cg_proto;
 192
 193         cg_proto = tcp_prot.proto_cgroup(memcg);
 194         if (!cg_proto)
 195                 return atomic_long_read(&tcp_memory_allocated) << PAGE_SHIFT;
 196
 197         tcp = tcp_from_cgproto(cg_proto);
 198         return res_counter_read_u64(&tcp->tcp_memory_allocated, RES_USAGE);
 199 }
 200
 201 static u64 tcp_cgroup_read(struct cgroup *cont, struct cftype *cft)
 202 {
 203         struct mem_cgroup *memcg = mem_cgroup_from_cont(cont);
 204         u64 val;
 205
 206         switch (cft->private) {
 207         case RES_LIMIT:
 208                 val = tcp_read_stat(memcg, RES_LIMIT, RESOURCE_MAX);
 209                 break;
 210         case RES_USAGE:
 211                 val = tcp_read_usage(memcg);
 212                 break;
 213         case RES_FAILCNT:
 214         case RES_MAX_USAGE:
 215                 val = tcp_read_stat(memcg, cft->private, 0);
 216                 break;
 217         default:
 218                 BUG();
 219         }
 220         return val;
 221 }
 222
 223 static int tcp_cgroup_reset(struct cgroup *cont, unsigned int event)
 224 {
 225         struct mem_cgroup *memcg;
 226         struct tcp_memcontrol *tcp;
 227         struct cg_proto *cg_proto;
 228
 229         memcg = mem_cgroup_from_cont(cont);
 230         cg_proto = tcp_prot.proto_cgroup(memcg);
 231         if (!cg_proto)
 232                 return 0;
 233         tcp = tcp_from_cgproto(cg_proto);
 234
 235         switch (event) {
 236         case RES_MAX_USAGE:
 237                 res_counter_reset_max(&tcp->tcp_memory_allocated);
 238                 break;
 239         case RES_FAILCNT:
 240                 res_counter_reset_failcnt(&tcp->tcp_memory_allocated);
 241                 break;
 242         }
 243
 244         return 0;
 245 }
 246
 247 unsigned long long tcp_max_memory(const struct mem_cgroup *memcg)
 248 {
 249         struct tcp_memcontrol *tcp;
 250         struct cg_proto *cg_proto;
 251
 252         cg_proto = tcp_prot.proto_cgroup((struct mem_cgroup *)memcg);
 253         if (!cg_proto)
 254                 return 0;
 255
 256         tcp = tcp_from_cgproto(cg_proto);
 257         return res_counter_read_u64(&tcp->tcp_memory_allocated, RES_LIMIT);
 258 }
 259
 260 void tcp_prot_mem(struct mem_cgroup *memcg, long val, int idx)
 261 {
 262         struct tcp_memcontrol *tcp;
 263         struct cg_proto *cg_proto;
 264
 265         cg_proto = tcp_prot.proto_cgroup(memcg);
 266         if (!cg_proto)
 267                 return;
 268
 269         tcp = tcp_from_cgproto(cg_proto);
 270
 271         tcp->tcp_prot_mem[idx] = val;
 272 }