[PATCH net-next 3/8] rxrpc: Trace rxrpc_call usage

From: David Howells
Date: Tue Aug 30 2016 - 11:43:59 EST

Next message: Ilia Mirkin: "Re: Kernel Freeze with American Megatrends BIOS"
Previous message: David Howells: "[PATCH net-next 6/8] rxrpc: Provide a way for AFS to ask for the peer address of a call"
In reply to: David Howells: "[PATCH net-next 6/8] rxrpc: Provide a way for AFS to ask for the peer address of a call"
Next in thread: David Miller: "Re: [PATCH net-next 0/8] rxrpc: Preparation for removal of use of skbs from AFS"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

Add a trace event for debuging rxrpc_call struct usage.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

include/trace/events/rxrpc.h | 39 ++++++++++++++++++
net/rxrpc/ar-internal.h | 19 ++-------
net/rxrpc/call_accept.c | 5 +-
net/rxrpc/call_event.c | 11 ++---
net/rxrpc/call_object.c | 90 +++++++++++++++++++++++++++++++++++++++---
net/rxrpc/conn_client.c | 1
net/rxrpc/conn_event.c | 1
net/rxrpc/input.c | 4 +-
net/rxrpc/output.c | 1
net/rxrpc/peer_event.c | 1
net/rxrpc/recvmsg.c | 1
net/rxrpc/skbuff.c | 4 --
12 files changed, 143 insertions(+), 34 deletions(-)

diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h
index 15283ee3e41a..cbe574ea674b 100644
--- a/include/trace/events/rxrpc.h
+++ b/include/trace/events/rxrpc.h
@@ -16,6 +16,45 @@

#include <linux/tracepoint.h>

+TRACE_EVENT(rxrpc_call,
+ TP_PROTO(struct rxrpc_call *call, int op, int usage, int nskb,
+ const void *where, const void *aux),
+
+ TP_ARGS(call, op, usage, nskb, where, aux),
+
+ TP_STRUCT__entry(
+ __field(struct rxrpc_call *, call )
+ __field(int, op )
+ __field(int, usage )
+ __field(int, nskb )
+ __field(const void *, where )
+ __field(const void *, aux )
+ ),
+
+ TP_fast_assign(
+ __entry->call = call;
+ __entry->op = op;
+ __entry->usage = usage;
+ __entry->nskb = nskb;
+ __entry->where = where;
+ __entry->aux = aux;
+ ),
+
+ TP_printk("c=%p %s u=%d s=%d p=%pSR a=%p",
+ __entry->call,
+ (__entry->op == 0 ? "NWc" :
+ __entry->op == 1 ? "NWs" :
+ __entry->op == 2 ? "SEE" :
+ __entry->op == 3 ? "GET" :
+ __entry->op == 4 ? "Gsb" :
+ __entry->op == 5 ? "PUT" :
+ "Psb"),
+ __entry->usage,
+ __entry->nskb,
+ __entry->where,
+ __entry->aux)
+ );
+
TRACE_EVENT(rxrpc_skb,
TP_PROTO(struct sk_buff *skb, int op, int usage, int mod_count,
const void *where),
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index ce6afd931e91..0c320b2b7b43 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -543,7 +543,11 @@ struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *,
struct sk_buff *);
void rxrpc_release_call(struct rxrpc_call *);
void rxrpc_release_calls_on_socket(struct rxrpc_sock *);
-void __rxrpc_put_call(struct rxrpc_call *);
+void rxrpc_see_call(struct rxrpc_call *);
+void rxrpc_get_call(struct rxrpc_call *);
+void rxrpc_put_call(struct rxrpc_call *);
+void rxrpc_get_call_for_skb(struct rxrpc_call *, struct sk_buff *);
+void rxrpc_put_call_for_skb(struct rxrpc_call *, struct sk_buff *);
void __exit rxrpc_destroy_all_calls(void);

static inline bool rxrpc_is_service_call(const struct rxrpc_call *call)
@@ -1022,16 +1026,3 @@ do { \
} while (0)

#endif /* __KDEBUGALL */
-
-
-#define rxrpc_get_call(CALL) \
-do { \
- CHECK_SLAB_OKAY(&(CALL)->usage); \
- if (atomic_inc_return(&(CALL)->usage) == 1) \
- BUG(); \
-} while (0)
-
-#define rxrpc_put_call(CALL) \
-do { \
- __rxrpc_put_call(CALL); \
-} while (0)
diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c
index ef9ef0d6c917..03af88fe798b 100644
--- a/net/rxrpc/call_accept.c
+++ b/net/rxrpc/call_accept.c
@@ -129,8 +129,7 @@ static int rxrpc_accept_incoming_call(struct rxrpc_local *local,
_debug("conn ready");
call->state = RXRPC_CALL_SERVER_ACCEPTING;
list_add_tail(&call->accept_link, &rx->acceptq);
- rxrpc_get_call(call);
- atomic_inc(&call->skb_count);
+ rxrpc_get_call_for_skb(call, notification);
nsp = rxrpc_skb(notification);
nsp->call = call;

@@ -323,6 +322,7 @@ struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx,
call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
list_del_init(&call->accept_link);
sk_acceptq_removed(&rx->sk);
+ rxrpc_see_call(call);

write_lock_bh(&call->state_lock);
switch (call->state) {
@@ -395,6 +395,7 @@ int rxrpc_reject_call(struct rxrpc_sock *rx)
call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link);
list_del_init(&call->accept_link);
sk_acceptq_removed(&rx->sk);
+ rxrpc_see_call(call);

write_lock_bh(&call->state_lock);
switch (call->state) {
diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index 94c7751fd99a..02fe4a4b60d9 100644
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -465,8 +465,7 @@ static void rxrpc_insert_oos_packet(struct rxrpc_call *call,
skb->destructor = rxrpc_packet_destructor;
ASSERTCMP(sp->call, ==, NULL);
sp->call = call;
- rxrpc_get_call(call);
- atomic_inc(&call->skb_count);
+ rxrpc_get_call_for_skb(call, skb);

/* insert into the buffer in sequence order */
spin_lock_bh(&call->lock);
@@ -741,8 +740,7 @@ all_acked:
_debug("post ACK");
skb->mark = RXRPC_SKB_MARK_FINAL_ACK;
sp->call = call;
- rxrpc_get_call(call);
- atomic_inc(&call->skb_count);
+ rxrpc_get_call_for_skb(call, skb);
spin_lock_bh(&call->lock);
if (rxrpc_queue_rcv_skb(call, skb, true, true) < 0)
BUG();
@@ -801,8 +799,7 @@ static int rxrpc_post_message(struct rxrpc_call *call, u32 mark, u32 error,
memset(sp, 0, sizeof(*sp));
sp->error = error;
sp->call = call;
- rxrpc_get_call(call);
- atomic_inc(&call->skb_count);
+ rxrpc_get_call_for_skb(call, skb);

spin_lock_bh(&call->lock);
ret = rxrpc_queue_rcv_skb(call, skb, true, fatal);
@@ -834,6 +831,8 @@ void rxrpc_process_call(struct work_struct *work)
u32 serial, abort_code = RX_PROTOCOL_ERROR;
u8 *acks = NULL;

+ rxrpc_see_call(call);
+
//printk("\n--------------------\n");
_enter("{%d,%s,%lx} [%lu]",
call->debug_id, rxrpc_call_states[call->state], call->events,
diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index 852c30dc7b75..104ee8b1de06 100644
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -219,6 +219,7 @@ struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
{
struct rxrpc_call *call, *xcall;
struct rb_node *parent, **pp;
+ const void *here = __builtin_return_address(0);
int ret;

_enter("%p,%lx", rx, user_call_ID);
@@ -229,6 +230,9 @@ struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
return call;
}

+ trace_rxrpc_call(call, 0, atomic_read(&call->usage), 0, here,
+ (const void *)user_call_ID);
+
/* Publish the call, even though it is incompletely set up as yet */
call->user_call_ID = user_call_ID;
__set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
@@ -308,6 +312,7 @@ struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
struct rxrpc_call *call, *candidate;
+ const void *here = __builtin_return_address(0);
u32 call_id, chan;

_enter(",%d", conn->debug_id);
@@ -318,6 +323,9 @@ struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx,
if (!candidate)
return ERR_PTR(-EBUSY);

+ trace_rxrpc_call(candidate, 1, atomic_read(&candidate->usage),
+ 0, here, NULL);
+
chan = sp->hdr.cid & RXRPC_CHANNELMASK;
candidate->socket = rx;
candidate->conn = conn;
@@ -431,6 +439,44 @@ old_call:
}

/*
+ * Note the re-emergence of a call.
+ */
+void rxrpc_see_call(struct rxrpc_call *call)
+{
+ const void *here = __builtin_return_address(0);
+ if (call) {
+ int n = atomic_read(&call->usage);
+ int m = atomic_read(&call->skb_count);
+
+ trace_rxrpc_call(call, 2, n, m, here, 0);
+ }
+}
+
+/*
+ * Note the addition of a ref on a call.
+ */
+void rxrpc_get_call(struct rxrpc_call *call)
+{
+ const void *here = __builtin_return_address(0);
+ int n = atomic_inc_return(&call->usage);
+ int m = atomic_read(&call->skb_count);
+
+ trace_rxrpc_call(call, 3, n, m, here, 0);
+}
+
+/*
+ * Note the addition of a ref on a call for a socket buffer.
+ */
+void rxrpc_get_call_for_skb(struct rxrpc_call *call, struct sk_buff *skb)
+{
+ const void *here = __builtin_return_address(0);
+ int n = atomic_inc_return(&call->usage);
+ int m = atomic_inc_return(&call->skb_count);
+
+ trace_rxrpc_call(call, 4, n, m, here, skb);
+}
+
+/*
* detach a call from a socket and set up for release
*/
void rxrpc_release_call(struct rxrpc_call *call)
@@ -443,6 +489,8 @@ void rxrpc_release_call(struct rxrpc_call *call)
atomic_read(&call->ackr_not_idle),
call->rx_first_oos);

+ rxrpc_see_call(call);
+
spin_lock_bh(&call->lock);
if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
BUG();
@@ -526,6 +574,7 @@ static void rxrpc_dead_call_expired(unsigned long _call)

_enter("{%d}", call->debug_id);

+ rxrpc_see_call(call);
write_lock_bh(&call->state_lock);
call->state = RXRPC_CALL_DEAD;
write_unlock_bh(&call->state_lock);
@@ -540,6 +589,7 @@ static void rxrpc_mark_call_released(struct rxrpc_call *call)
{
bool sched;

+ rxrpc_see_call(call);
write_lock(&call->state_lock);
if (call->state < RXRPC_CALL_DEAD) {
sched = __rxrpc_abort_call(call, RX_CALL_DEAD, ECONNRESET);
@@ -585,21 +635,43 @@ void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
/*
* release a call
*/
-void __rxrpc_put_call(struct rxrpc_call *call)
+void rxrpc_put_call(struct rxrpc_call *call)
{
- ASSERT(call != NULL);
+ const void *here = __builtin_return_address(0);
+ int n, m;

- _enter("%p{u=%d}", call, atomic_read(&call->usage));
+ ASSERT(call != NULL);

- ASSERTCMP(atomic_read(&call->usage), >, 0);
+ n = atomic_dec_return(&call->usage);
+ m = atomic_read(&call->skb_count);
+ trace_rxrpc_call(call, 5, n, m, here, NULL);
+ ASSERTCMP(n, >=, 0);
+ if (n == 0) {
+ _debug("call %d dead", call->debug_id);
+ WARN_ON(m != 0);
+ ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
+ rxrpc_queue_work(&call->destroyer);
+ }
+}

- if (atomic_dec_and_test(&call->usage)) {
+/*
+ * Release a call ref held by a socket buffer.
+ */
+void rxrpc_put_call_for_skb(struct rxrpc_call *call, struct sk_buff *skb)
+{
+ const void *here = __builtin_return_address(0);
+ int n, m;
+
+ n = atomic_dec_return(&call->usage);
+ m = atomic_dec_return(&call->skb_count);
+ trace_rxrpc_call(call, 6, n, m, here, skb);
+ ASSERTCMP(n, >=, 0);
+ if (n == 0) {
_debug("call %d dead", call->debug_id);
- WARN_ON(atomic_read(&call->skb_count) != 0);
+ WARN_ON(m != 0);
ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD);
rxrpc_queue_work(&call->destroyer);
}
- _leave("");
}

/*
@@ -705,6 +777,7 @@ void __exit rxrpc_destroy_all_calls(void)
call = list_entry(rxrpc_calls.next, struct rxrpc_call, link);
_debug("Zapping call %p", call);

+ rxrpc_see_call(call);
list_del_init(&call->link);

switch (atomic_read(&call->usage)) {
@@ -748,6 +821,7 @@ static void rxrpc_call_life_expired(unsigned long _call)

_enter("{%d}", call->debug_id);

+ rxrpc_see_call(call);
if (call->state >= RXRPC_CALL_COMPLETE)
return;

@@ -765,6 +839,7 @@ static void rxrpc_resend_time_expired(unsigned long _call)

_enter("{%d}", call->debug_id);

+ rxrpc_see_call(call);
if (call->state >= RXRPC_CALL_COMPLETE)
return;

@@ -782,6 +857,7 @@ static void rxrpc_ack_time_expired(unsigned long _call)

_enter("{%d}", call->debug_id);

+ rxrpc_see_call(call);
if (call->state >= RXRPC_CALL_COMPLETE)
return;

diff --git a/net/rxrpc/conn_client.c b/net/rxrpc/conn_client.c
index 44850a2d90b5..4b213bc0f554 100644
--- a/net/rxrpc/conn_client.c
+++ b/net/rxrpc/conn_client.c
@@ -537,6 +537,7 @@ static void rxrpc_activate_one_channel(struct rxrpc_connection *conn,
struct rxrpc_call, chan_wait_link);
u32 call_id = chan->call_counter + 1;

+ rxrpc_see_call(call);
list_del_init(&call->chan_wait_link);
conn->active_chans |= 1 << channel;
call->peer = rxrpc_get_peer(conn->params.peer);
diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c
index bcea99c73b40..bc9b05938ff5 100644
--- a/net/rxrpc/conn_event.c
+++ b/net/rxrpc/conn_event.c
@@ -157,6 +157,7 @@ static void rxrpc_abort_calls(struct rxrpc_connection *conn,
conn->channels[i].call,
lockdep_is_held(&conn->channel_lock));
if (call) {
+ rxrpc_see_call(call);
write_lock_bh(&call->state_lock);
if (rxrpc_set_call_completion(call, compl, abort_code,
error)) {
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index af49c2992c4a..86bea9ad6c3d 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -196,8 +196,7 @@ static int rxrpc_fast_process_data(struct rxrpc_call *call,
goto enqueue_packet;

sp->call = call;
- rxrpc_get_call(call);
- atomic_inc(&call->skb_count);
+ rxrpc_get_call_for_skb(call, skb);
terminal = ((flags & RXRPC_LAST_PACKET) &&
!(flags & RXRPC_CLIENT_INITIATED));
ret = rxrpc_queue_rcv_skb(call, skb, false, terminal);
@@ -748,6 +747,7 @@ void rxrpc_data_ready(struct sock *sk)
if (!call || atomic_read(&call->usage) == 0)
goto cant_route_call;

+ rxrpc_see_call(call);
rxrpc_post_packet_to_call(call, skb);
goto out_unlock;
}
diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index 036e1112b0c5..888fa87ed1d6 100644
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -207,6 +207,7 @@ int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
return PTR_ERR(call);
}

+ rxrpc_see_call(call);
_debug("CALL %d USR %lx ST %d on CONN %p",
call->debug_id, call->user_call_ID, call->state, call->conn);

diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c
index 865078d76ad3..27b9ecad007e 100644
--- a/net/rxrpc/peer_event.c
+++ b/net/rxrpc/peer_event.c
@@ -270,6 +270,7 @@ void rxrpc_peer_error_distributor(struct work_struct *work)
call = hlist_entry(peer->error_targets.first,
struct rxrpc_call, error_link);
hlist_del_init(&call->error_link);
+ rxrpc_see_call(call);

queue = false;
write_lock(&call->state_lock);
diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c
index 96d98a3a7087..c9b38c7fb448 100644
--- a/net/rxrpc/recvmsg.c
+++ b/net/rxrpc/recvmsg.c
@@ -115,6 +115,7 @@ int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
sp = rxrpc_skb(skb);
call = sp->call;
ASSERT(call != NULL);
+ rxrpc_see_call(call);

_debug("next pkt %s", rxrpc_pkts[sp->hdr.type]);

diff --git a/net/rxrpc/skbuff.c b/net/rxrpc/skbuff.c
index fbd8c74d9505..20529205bb8c 100644
--- a/net/rxrpc/skbuff.c
+++ b/net/rxrpc/skbuff.c
@@ -140,9 +140,7 @@ void rxrpc_packet_destructor(struct sk_buff *skb)
_enter("%p{%p}", skb, call);

if (call) {
- if (atomic_dec_return(&call->skb_count) < 0)
- BUG();
- rxrpc_put_call(call);
+ rxrpc_put_call_for_skb(call, skb);
sp->call = NULL;
}

Next message: Ilia Mirkin: "Re: Kernel Freeze with American Megatrends BIOS"
Previous message: David Howells: "[PATCH net-next 6/8] rxrpc: Provide a way for AFS to ask for the peer address of a call"
In reply to: David Howells: "[PATCH net-next 6/8] rxrpc: Provide a way for AFS to ask for the peer address of a call"
Next in thread: David Miller: "Re: [PATCH net-next 0/8] rxrpc: Preparation for removal of use of skbs from AFS"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]