xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

net: memcg: late association of sock to memcg

Browse Source 
If a TCP socket is allocated in IRQ context or cloned from unassociated
(i.e. not associated to a memcg) in IRQ context then it will remain
unassociated for its whole life. Almost half of the TCPs created on the
system are created in IRQ context, so, memory used by such sockets will
not be accounted by the memcg.

This issue is more widespread in cgroup v1 where network memory
accounting is opt-in but it can happen in cgroup v2 if the source socket
for the cloning was created in root memcg.

To fix the issue, just do the association of the sockets at the accept()
time in the process context and then force charge the memory buffer
already used and reserved by the socket.

Signed-off-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Shakeel Butt
2020-03-09 22:16:06 -07:00
committed by David S. Miller
parent e876ecc67d
commit d752a49865
3 changed files with 24 additions and 15 deletions
Download Patch File Download Diff File Expand all files Collapse all files

20
net/ipv4/inet_connection_sock.c
View File

@@ -482,6 +482,26 @@ struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern)
}
spin_unlock_bh(&queue->fastopenq.lock);
}
if (mem_cgroup_sockets_enabled) {
int amt;
/* atomically get the memory usage, set and charge the
* sk->sk_memcg.
*/
lock_sock(newsk);
/* The sk has not been accepted yet, no need to look at
* sk->sk_wmem_queued.
*/
amt = sk_mem_pages(newsk->sk_forward_alloc +
atomic_read(&sk->sk_rmem_alloc));
mem_cgroup_sk_alloc(newsk);
if (newsk->sk_memcg && amt)
mem_cgroup_charge_skmem(newsk->sk_memcg, amt);
release_sock(newsk);
}
out:
release_sock(sk);
if (req)