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rxrpc: Add a tracepoint to track rxrpc_local refcounting
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Add a tracepoint to track reference counting on the rxrpc_local struct.

Signed-off-by: David Howells <dhowells@redhat.com>
dhowells committed Mar 30, 2018

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This commit is not signed, but one or more authors requires that any commit attributed to them is signed.
1 parent d3be4d2 commit 09d2bf5
Showing 4 changed files with 111 additions and 27 deletions.
43 changes: 43 additions & 0 deletions include/trace/events/rxrpc.h
Original file line number Diff line number Diff line change
@@ -42,6 +42,14 @@ enum rxrpc_skb_trace {
rxrpc_skb_tx_seen,
};

enum rxrpc_local_trace {
rxrpc_local_got,
rxrpc_local_new,
rxrpc_local_processing,
rxrpc_local_put,
rxrpc_local_queued,
};

enum rxrpc_conn_trace {
rxrpc_conn_got,
rxrpc_conn_new_client,
@@ -215,6 +223,13 @@ enum rxrpc_congest_change {
EM(rxrpc_skb_tx_rotated, "Tx ROT") \
E_(rxrpc_skb_tx_seen, "Tx SEE")

#define rxrpc_local_traces \
EM(rxrpc_local_got, "GOT") \
EM(rxrpc_local_new, "NEW") \
EM(rxrpc_local_processing, "PRO") \
EM(rxrpc_local_put, "PUT") \
E_(rxrpc_local_queued, "QUE")

#define rxrpc_conn_traces \
EM(rxrpc_conn_got, "GOT") \
EM(rxrpc_conn_new_client, "NWc") \
@@ -416,6 +431,7 @@ enum rxrpc_congest_change {
#define E_(a, b) TRACE_DEFINE_ENUM(a);

rxrpc_skb_traces;
rxrpc_local_traces;
rxrpc_conn_traces;
rxrpc_client_traces;
rxrpc_call_traces;
@@ -439,6 +455,33 @@ rxrpc_congest_changes;
#define EM(a, b) { a, b },
#define E_(a, b) { a, b }

TRACE_EVENT(rxrpc_local,
TP_PROTO(struct rxrpc_local *local, enum rxrpc_local_trace op,
int usage, const void *where),

TP_ARGS(local, op, usage, where),

TP_STRUCT__entry(
__field(unsigned int, local )
__field(int, op )
__field(int, usage )
__field(const void *, where )
),

TP_fast_assign(
__entry->local = local->debug_id;
__entry->op = op;
__entry->usage = usage;
__entry->where = where;
),

TP_printk("L=%08x %s u=%d sp=%pSR",
__entry->local,
__print_symbolic(__entry->op, rxrpc_local_traces),
__entry->usage,
__entry->where)
);

TRACE_EVENT(rxrpc_conn,
TP_PROTO(struct rxrpc_connection *conn, enum rxrpc_conn_trace op,
int usage, const void *where),
27 changes: 4 additions & 23 deletions net/rxrpc/ar-internal.h
Original file line number Diff line number Diff line change
@@ -981,31 +981,12 @@ extern void rxrpc_process_local_events(struct rxrpc_local *);
* local_object.c
*/
struct rxrpc_local *rxrpc_lookup_local(struct net *, const struct sockaddr_rxrpc *);
void __rxrpc_put_local(struct rxrpc_local *);
struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *);
struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *);
void rxrpc_put_local(struct rxrpc_local *);
void rxrpc_queue_local(struct rxrpc_local *);
void rxrpc_destroy_all_locals(struct rxrpc_net *);

static inline void rxrpc_get_local(struct rxrpc_local *local)
{
atomic_inc(&local->usage);
}

static inline
struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *local)
{
return atomic_inc_not_zero(&local->usage) ? local : NULL;
}

static inline void rxrpc_put_local(struct rxrpc_local *local)
{
if (local && atomic_dec_and_test(&local->usage))
__rxrpc_put_local(local);
}

static inline void rxrpc_queue_local(struct rxrpc_local *local)
{
rxrpc_queue_work(&local->processor);
}

/*
* misc.c
*/
3 changes: 1 addition & 2 deletions net/rxrpc/call_accept.c
Original file line number Diff line number Diff line change
@@ -296,8 +296,7 @@ static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
b->conn_backlog[conn_tail] = NULL;
smp_store_release(&b->conn_backlog_tail,
(conn_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
rxrpc_get_local(local);
conn->params.local = local;
conn->params.local = rxrpc_get_local(local);
conn->params.peer = peer;
rxrpc_see_connection(conn);
rxrpc_new_incoming_connection(rx, conn, skb);
65 changes: 63 additions & 2 deletions net/rxrpc/local_object.c
Original file line number Diff line number Diff line change
@@ -95,6 +95,7 @@ static struct rxrpc_local *rxrpc_alloc_local(struct rxrpc_net *rxnet,
local->debug_id = atomic_inc_return(&rxrpc_debug_id);
memcpy(&local->srx, srx, sizeof(*srx));
local->srx.srx_service = 0;
trace_rxrpc_local(local, rxrpc_local_new, 1, NULL);
}

_leave(" = %p", local);
@@ -256,15 +257,74 @@ struct rxrpc_local *rxrpc_lookup_local(struct net *net,
return ERR_PTR(-EADDRINUSE);
}

/*
* Get a ref on a local endpoint.
*/
struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *local)
{
const void *here = __builtin_return_address(0);
int n;

n = atomic_inc_return(&local->usage);
trace_rxrpc_local(local, rxrpc_local_got, n, here);
return local;
}

/*
* Get a ref on a local endpoint unless its usage has already reached 0.
*/
struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *local)
{
const void *here = __builtin_return_address(0);

if (local) {
int n = __atomic_add_unless(&local->usage, 1, 0);
if (n > 0)
trace_rxrpc_local(local, rxrpc_local_got, n + 1, here);
else
local = NULL;
}
return local;
}

/*
* Queue a local endpoint.
*/
void rxrpc_queue_local(struct rxrpc_local *local)
{
const void *here = __builtin_return_address(0);

if (rxrpc_queue_work(&local->processor))
trace_rxrpc_local(local, rxrpc_local_queued,
atomic_read(&local->usage), here);
}

/*
* A local endpoint reached its end of life.
*/
void __rxrpc_put_local(struct rxrpc_local *local)
static void __rxrpc_put_local(struct rxrpc_local *local)
{
_enter("%d", local->debug_id);
rxrpc_queue_work(&local->processor);
}

/*
* Drop a ref on a local endpoint.
*/
void rxrpc_put_local(struct rxrpc_local *local)
{
const void *here = __builtin_return_address(0);
int n;

if (local) {
n = atomic_dec_return(&local->usage);
trace_rxrpc_local(local, rxrpc_local_put, n, here);

if (n == 0)
__rxrpc_put_local(local);
}
}

/*
* Destroy a local endpoint's socket and then hand the record to RCU to dispose
* of.
@@ -322,7 +382,8 @@ static void rxrpc_local_processor(struct work_struct *work)
container_of(work, struct rxrpc_local, processor);
bool again;

_enter("%d", local->debug_id);
trace_rxrpc_local(local, rxrpc_local_processing,
atomic_read(&local->usage), NULL);

do {
again = false;

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