2018-07-01 15:32:45

by Yafang Shao

Subject: [PATCH] net: expose sk wmem in sock_exceed_buf_limit tracepoint

Currently trace_sock_exceed_buf_limit() only show rmem info,
but wmem limit may also be hit.
So expose wmem info in this tracepoint as well.

Regarding memcg, I think it is better to introduce a new tracepoint(if
that is needed), i.e. trace_memcg_limit_hit other than show memcg info in
trace_sock_exceed_buf_limit.

Signed-off-by: Yafang Shao <[email protected]>
---
include/trace/events/sock.h | 30 +++++++++++++++++++++++++-----
net/core/sock.c | 6 ++++--
2 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/include/trace/events/sock.h b/include/trace/events/sock.h
index 3176a39..a0c4b8a 100644
--- a/include/trace/events/sock.h
+++ b/include/trace/events/sock.h
@@ -35,6 +35,10 @@
EM(TCP_CLOSING) \
EMe(TCP_NEW_SYN_RECV)

+#define skmem_kind_names \
+ EM(SK_MEM_SEND) \
+ EMe(SK_MEM_RECV)
+
/* enums need to be exported to user space */
#undef EM
#undef EMe
@@ -44,6 +48,7 @@
family_names
inet_protocol_names
tcp_state_names
+skmem_kind_names

#undef EM
#undef EMe
@@ -59,6 +64,9 @@
#define show_tcp_state_name(val) \
__print_symbolic(val, tcp_state_names)

+#define show_skmem_kind_names(val) \
+ __print_symbolic(val, skmem_kind_names)
+
TRACE_EVENT(sock_rcvqueue_full,

TP_PROTO(struct sock *sk, struct sk_buff *skb),
@@ -83,9 +91,9 @@

TRACE_EVENT(sock_exceed_buf_limit,

- TP_PROTO(struct sock *sk, struct proto *prot, long allocated),
+ TP_PROTO(struct sock *sk, struct proto *prot, long allocated, int kind),

- TP_ARGS(sk, prot, allocated),
+ TP_ARGS(sk, prot, allocated, kind),

TP_STRUCT__entry(
__array(char, name, 32)
@@ -93,6 +101,10 @@
__field(long, allocated)
__field(int, sysctl_rmem)
__field(int, rmem_alloc)
+ __field(int, sysctl_wmem)
+ __field(int, wmem_alloc)
+ __field(int, wmem_queued)
+ __field(int, kind)
),

TP_fast_assign(
@@ -101,17 +113,25 @@
__entry->allocated = allocated;
__entry->sysctl_rmem = sk_get_rmem0(sk, prot);
__entry->rmem_alloc = atomic_read(&sk->sk_rmem_alloc);
+ __entry->sysctl_wmem = sk_get_wmem0(sk, prot);
+ __entry->wmem_alloc = refcount_read(&sk->sk_wmem_alloc);
+ __entry->wmem_queued = sk->sk_wmem_queued;
+ __entry->kind = kind;
),

- TP_printk("proto:%s sysctl_mem=%ld,%ld,%ld allocated=%ld "
- "sysctl_rmem=%d rmem_alloc=%d",
+ TP_printk("proto:%s sysctl_mem=%ld,%ld,%ld allocated=%ld sysctl_rmem=%d rmem_alloc=%d sysctl_wmem=%d wmem_alloc=%d wmem_queued=%d kind=%s",
__entry->name,
__entry->sysctl_mem[0],
__entry->sysctl_mem[1],
__entry->sysctl_mem[2],
__entry->allocated,
__entry->sysctl_rmem,
- __entry->rmem_alloc)
+ __entry->rmem_alloc,
+ __entry->sysctl_wmem,
+ __entry->wmem_alloc,
+ __entry->wmem_queued,
+ show_skmem_kind_names(__entry->kind)
+ )
);

TRACE_EVENT(inet_sock_set_state,
diff --git a/net/core/sock.c b/net/core/sock.c
index bcc4182..65350ed 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2401,9 +2401,10 @@ int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
{
struct proto *prot = sk->sk_prot;
long allocated = sk_memory_allocated_add(sk, amt);
+ bool charged = true;

if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
- !mem_cgroup_charge_skmem(sk->sk_memcg, amt))
+ !(charged = mem_cgroup_charge_skmem(sk->sk_memcg, amt)))
goto suppress_allocation;

/* Under limit. */
@@ -2461,7 +2462,8 @@ int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind)
return 1;
}

- trace_sock_exceed_buf_limit(sk, prot, allocated);
+ if (kind == SK_MEM_SEND || (kind == SK_MEM_RECV && charged))
+ trace_sock_exceed_buf_limit(sk, prot, allocated, kind);

sk_memory_allocated_sub(sk, amt);

--
1.8.3.1

2018-07-02 13:45:10

by David Miller

Subject: Re: [PATCH] net: expose sk wmem in sock_exceed_buf_limit tracepoint

From: Yafang Shao <[email protected]>
Date: Sun, 1 Jul 2018 23:31:30 +0800

> Currently trace_sock_exceed_buf_limit() only show rmem info,
> but wmem limit may also be hit.
> So expose wmem info in this tracepoint as well.
>
> Regarding memcg, I think it is better to introduce a new tracepoint(if
> that is needed), i.e. trace_memcg_limit_hit other than show memcg info in
> trace_sock_exceed_buf_limit.
>
> Signed-off-by: Yafang Shao <[email protected]>

Applied to net-next.