static int tcp_update_limit(struct mem_cgroup *memcg, u64 val)
{
struct net *net = current->nsproxy->net_ns;
struct tcp_memcontrol *tcp;
struct cg_proto *cg_proto;
u64 old_lim;
int i;
int ret;
cg_proto = tcp_prot.proto_cgroup(memcg);
if (!cg_proto)
return -EINVAL;
if (val > RESOURCE_MAX)
val = RESOURCE_MAX;
tcp = tcp_from_cgproto(cg_proto);
old_lim = res_counter_read_u64(&tcp->tcp_memory_allocated, RES_LIMIT);
ret = res_counter_set_limit(&tcp->tcp_memory_allocated, val);
if (ret)
return ret;
for (i = 0; i < 3; i++)
tcp->tcp_prot_mem[i] = min_t(long, val >> PAGE_SHIFT,
net->ipv4.sysctl_tcp_mem[i]);
if (val == RESOURCE_MAX && old_lim != RESOURCE_MAX)
static_key_slow_dec(&memcg_socket_limit_enabled);
else if (old_lim == RESOURCE_MAX && val != RESOURCE_MAX)
static_key_slow_inc(&memcg_socket_limit_enabled);
return 0;
}
static int tcp_update_limit(struct mem_cgroup *memcg, u64 val)
{
struct cg_proto *cg_proto;
int i;
int ret;
cg_proto = tcp_prot.proto_cgroup(memcg);
if (!cg_proto)
return -EINVAL;
if (val > RES_COUNTER_MAX)
val = RES_COUNTER_MAX;
ret = res_counter_set_limit(&cg_proto->memory_allocated, val);
if (ret)
return ret;
for (i = 0; i < 3; i++)
cg_proto->sysctl_mem[i] = min_t(long, val >> PAGE_SHIFT,
sysctl_tcp_mem[i]);
if (val == RES_COUNTER_MAX)
clear_bit(MEMCG_SOCK_ACTIVE, &cg_proto->flags);
else if (val != RES_COUNTER_MAX) {
/*
* 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;
}
