From 09d2bf595db4b4075ea721acd61e180d6bb18f88 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Mar 2018 21:05:28 +0100 Subject: [PATCH] rxrpc: Add a tracepoint to track rxrpc_local refcounting Add a tracepoint to track reference counting on the rxrpc_local struct. Signed-off-by: David Howells --- include/trace/events/rxrpc.h | 43 ++++++++++++++++++++++++ net/rxrpc/ar-internal.h | 27 +++------------ net/rxrpc/call_accept.c | 3 +- net/rxrpc/local_object.c | 65 ++++++++++++++++++++++++++++++++++-- 4 files changed, 111 insertions(+), 27 deletions(-) diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h index 2ea788f6f95d..0410dfeb79c6 100644 --- a/include/trace/events/rxrpc.h +++ b/include/trace/events/rxrpc.h @@ -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), diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h index 2a2b0fdfb157..cc51d3eb0548 100644 --- a/net/rxrpc/ar-internal.h +++ b/net/rxrpc/ar-internal.h @@ -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 */ diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c index 493545033e42..5a9b1d916124 100644 --- a/net/rxrpc/call_accept.c +++ b/net/rxrpc/call_accept.c @@ -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); diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c index 38b99db30e54..8b54e9531d52 100644 --- a/net/rxrpc/local_object.c +++ b/net/rxrpc/local_object.c @@ -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 @@ addr_in_use: 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;