diff options
Diffstat (limited to 'net/ipv4/tcp_memcontrol.c')
| -rw-r--r-- | net/ipv4/tcp_memcontrol.c | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/net/ipv4/tcp_memcontrol.c b/net/ipv4/tcp_memcontrol.c new file mode 100644 index 000000000..2379c1b4e --- /dev/null +++ b/net/ipv4/tcp_memcontrol.c @@ -0,0 +1,233 @@ +#include <net/tcp.h> +#include <net/tcp_memcontrol.h> +#include <net/sock.h> +#include <net/ip.h> +#include <linux/nsproxy.h> +#include <linux/memcontrol.h> +#include <linux/module.h> + +int tcp_init_cgroup(struct mem_cgroup *memcg, struct cgroup_subsys *ss) +{ + /* + * The root cgroup does not use page_counters, but rather, + * rely on the data already collected by the network + * subsystem + */ + struct mem_cgroup *parent = parent_mem_cgroup(memcg); + struct page_counter *counter_parent = NULL; + struct cg_proto *cg_proto, *parent_cg; + + cg_proto = tcp_prot.proto_cgroup(memcg); + if (!cg_proto) + return 0; + + cg_proto->sysctl_mem[0] = sysctl_tcp_mem[0]; + cg_proto->sysctl_mem[1] = sysctl_tcp_mem[1]; + cg_proto->sysctl_mem[2] = sysctl_tcp_mem[2]; + cg_proto->memory_pressure = 0; + cg_proto->memcg = memcg; + + parent_cg = tcp_prot.proto_cgroup(parent); + if (parent_cg) + counter_parent = &parent_cg->memory_allocated; + + page_counter_init(&cg_proto->memory_allocated, counter_parent); + percpu_counter_init(&cg_proto->sockets_allocated, 0, GFP_KERNEL); + + return 0; +} +EXPORT_SYMBOL(tcp_init_cgroup); + +void tcp_destroy_cgroup(struct mem_cgroup *memcg) +{ + struct cg_proto *cg_proto; + + cg_proto = tcp_prot.proto_cgroup(memcg); + if (!cg_proto) + return; + + percpu_counter_destroy(&cg_proto->sockets_allocated); + + if (test_bit(MEMCG_SOCK_ACTIVATED, &cg_proto->flags)) + static_key_slow_dec(&memcg_socket_limit_enabled); + +} +EXPORT_SYMBOL(tcp_destroy_cgroup); + +static int tcp_update_limit(struct mem_cgroup *memcg, unsigned long nr_pages) +{ + struct cg_proto *cg_proto; + int i; + int ret; + + cg_proto = tcp_prot.proto_cgroup(memcg); + if (!cg_proto) + return -EINVAL; + + ret = page_counter_limit(&cg_proto->memory_allocated, nr_pages); + if (ret) + return ret; + + for (i = 0; i < 3; i++) + cg_proto->sysctl_mem[i] = min_t(long, nr_pages, + sysctl_tcp_mem[i]); + + if (nr_pages == PAGE_COUNTER_MAX) + clear_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags); + else { + /* + * The active bit needs to be written after the static_key + * update. This is what guarantees that the socket activation + * function is the last one to run. See sock_update_memcg() for + * details, and note that we don't mark any socket as belonging + * to this memcg until that flag is up. + * + * We need to do this, because static_keys will span multiple + * sites, but we can't control their order. If we mark a socket + * as accounted, but the accounting functions are not patched in + * yet, we'll lose accounting. + * + * We never race with the readers in sock_update_memcg(), + * because when this value change, the code to process it is not + * patched in yet. + * + * The activated bit is used to guarantee that no two writers + * will do the update in the same memcg. Without that, we can't + * properly shutdown the static key. + */ + if (!test_and_set_bit(MEMCG_SOCK_ACTIVATED, &cg_proto->flags)) + static_key_slow_inc(&memcg_socket_limit_enabled); + set_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags); + } + + return 0; +} + +enum { + RES_USAGE, + RES_LIMIT, + RES_MAX_USAGE, + RES_FAILCNT, +}; + +static DEFINE_MUTEX(tcp_limit_mutex); + +static ssize_t tcp_cgroup_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of)); + unsigned long nr_pages; + int ret = 0; + + buf = strstrip(buf); + + switch (of_cft(of)->private) { + case RES_LIMIT: + /* see memcontrol.c */ + ret = page_counter_memparse(buf, "-1", &nr_pages); + if (ret) + break; + mutex_lock(&tcp_limit_mutex); + ret = tcp_update_limit(memcg, nr_pages); + mutex_unlock(&tcp_limit_mutex); + break; + default: + ret = -EINVAL; + break; + } + return ret ?: nbytes; +} + +static u64 tcp_cgroup_read(struct cgroup_subsys_state *css, struct cftype *cft) +{ + struct mem_cgroup *memcg = mem_cgroup_from_css(css); + struct cg_proto *cg_proto = tcp_prot.proto_cgroup(memcg); + u64 val; + + switch (cft->private) { + case RES_LIMIT: + if (!cg_proto) + return PAGE_COUNTER_MAX; + val = cg_proto->memory_allocated.limit; + val *= PAGE_SIZE; + break; + case RES_USAGE: + if (!cg_proto) + val = atomic_long_read(&tcp_memory_allocated); + else + val = page_counter_read(&cg_proto->memory_allocated); + val *= PAGE_SIZE; + break; + case RES_FAILCNT: + if (!cg_proto) + return 0; + val = cg_proto->memory_allocated.failcnt; + break; + case RES_MAX_USAGE: + if (!cg_proto) + return 0; + val = cg_proto->memory_allocated.watermark; + val *= PAGE_SIZE; + break; + default: + BUG(); + } + return val; +} + +static ssize_t tcp_cgroup_reset(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + struct mem_cgroup *memcg; + struct cg_proto *cg_proto; + + memcg = mem_cgroup_from_css(of_css(of)); + cg_proto = tcp_prot.proto_cgroup(memcg); + if (!cg_proto) + return nbytes; + + switch (of_cft(of)->private) { + case RES_MAX_USAGE: + page_counter_reset_watermark(&cg_proto->memory_allocated); + break; + case RES_FAILCNT: + cg_proto->memory_allocated.failcnt = 0; + break; + } + + return nbytes; +} + +static struct cftype tcp_files[] = { + { + .name = "kmem.tcp.limit_in_bytes", + .write = tcp_cgroup_write, + .read_u64 = tcp_cgroup_read, + .private = RES_LIMIT, + }, + { + .name = "kmem.tcp.usage_in_bytes", + .read_u64 = tcp_cgroup_read, + .private = RES_USAGE, + }, + { + .name = "kmem.tcp.failcnt", + .private = RES_FAILCNT, + .write = tcp_cgroup_reset, + .read_u64 = tcp_cgroup_read, + }, + { + .name = "kmem.tcp.max_usage_in_bytes", + .private = RES_MAX_USAGE, + .write = tcp_cgroup_reset, + .read_u64 = tcp_cgroup_read, + }, + { } /* terminate */ +}; + +static int __init tcp_memcontrol_init(void) +{ + WARN_ON(cgroup_add_legacy_cftypes(&memory_cgrp_subsys, tcp_files)); + return 0; +} +__initcall(tcp_memcontrol_init); |