From 1159d4b496f57d5b8ee27c8b90b9d01c332e2e11 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Mar 2018 21:05:38 +0100 Subject: [PATCH] rxrpc: Add a tracepoint to track rxrpc_peer refcounting Add a tracepoint to track reference counting on the rxrpc_peer struct. Signed-off-by: David Howells --- include/trace/events/rxrpc.h | 42 +++++++++++++++++++++++ net/rxrpc/ar-internal.h | 23 +++---------- net/rxrpc/peer_event.c | 2 +- net/rxrpc/peer_object.c | 65 ++++++++++++++++++++++++++++++++++-- 4 files changed, 110 insertions(+), 22 deletions(-) diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h index 0410dfeb79c6..9e96c2fe2793 100644 --- a/include/trace/events/rxrpc.h +++ b/include/trace/events/rxrpc.h @@ -50,6 +50,14 @@ enum rxrpc_local_trace { rxrpc_local_queued, }; +enum rxrpc_peer_trace { + rxrpc_peer_got, + rxrpc_peer_new, + rxrpc_peer_processing, + rxrpc_peer_put, + rxrpc_peer_queued_error, +}; + enum rxrpc_conn_trace { rxrpc_conn_got, rxrpc_conn_new_client, @@ -230,6 +238,13 @@ enum rxrpc_congest_change { EM(rxrpc_local_put, "PUT") \ E_(rxrpc_local_queued, "QUE") +#define rxrpc_peer_traces \ + EM(rxrpc_peer_got, "GOT") \ + EM(rxrpc_peer_new, "NEW") \ + EM(rxrpc_peer_processing, "PRO") \ + EM(rxrpc_peer_put, "PUT") \ + E_(rxrpc_peer_queued_error, "QER") + #define rxrpc_conn_traces \ EM(rxrpc_conn_got, "GOT") \ EM(rxrpc_conn_new_client, "NWc") \ @@ -482,6 +497,33 @@ TRACE_EVENT(rxrpc_local, __entry->where) ); +TRACE_EVENT(rxrpc_peer, + TP_PROTO(struct rxrpc_peer *peer, enum rxrpc_peer_trace op, + int usage, const void *where), + + TP_ARGS(peer, op, usage, where), + + TP_STRUCT__entry( + __field(unsigned int, peer ) + __field(int, op ) + __field(int, usage ) + __field(const void *, where ) + ), + + TP_fast_assign( + __entry->peer = peer->debug_id; + __entry->op = op; + __entry->usage = usage; + __entry->where = where; + ), + + TP_printk("P=%08x %s u=%d sp=%pSR", + __entry->peer, + __print_symbolic(__entry->op, rxrpc_peer_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 d40d54b78567..c46583bc255d 100644 --- a/net/rxrpc/ar-internal.h +++ b/net/rxrpc/ar-internal.h @@ -1041,25 +1041,10 @@ struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_local *, struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *, gfp_t); struct rxrpc_peer *rxrpc_lookup_incoming_peer(struct rxrpc_local *, struct rxrpc_peer *); - -static inline struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *peer) -{ - atomic_inc(&peer->usage); - return peer; -} - -static inline -struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *peer) -{ - return atomic_inc_not_zero(&peer->usage) ? peer : NULL; -} - -extern void __rxrpc_put_peer(struct rxrpc_peer *peer); -static inline void rxrpc_put_peer(struct rxrpc_peer *peer) -{ - if (peer && atomic_dec_and_test(&peer->usage)) - __rxrpc_put_peer(peer); -} +struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *); +struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *); +void rxrpc_put_peer(struct rxrpc_peer *); +void __rxrpc_queue_peer_error(struct rxrpc_peer *); /* * proc.c diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c index d01eb9a06448..78c2f95d1f22 100644 --- a/net/rxrpc/peer_event.c +++ b/net/rxrpc/peer_event.c @@ -192,7 +192,7 @@ void rxrpc_error_report(struct sock *sk) rxrpc_free_skb(skb, rxrpc_skb_rx_freed); /* The ref we obtained is passed off to the work item */ - rxrpc_queue_work(&peer->error_distributor); + __rxrpc_queue_peer_error(peer); _leave(""); } diff --git a/net/rxrpc/peer_object.c b/net/rxrpc/peer_object.c index 94a6dbfcf129..a4a750aea1e5 100644 --- a/net/rxrpc/peer_object.c +++ b/net/rxrpc/peer_object.c @@ -386,9 +386,54 @@ struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_local *local, } /* - * Discard a ref on a remote peer record. + * Get a ref on a peer record. */ -void __rxrpc_put_peer(struct rxrpc_peer *peer) +struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *peer) +{ + const void *here = __builtin_return_address(0); + int n; + + n = atomic_inc_return(&peer->usage); + trace_rxrpc_peer(peer, rxrpc_peer_got, n, here); + return peer; +} + +/* + * Get a ref on a peer record unless its usage has already reached 0. + */ +struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *peer) +{ + const void *here = __builtin_return_address(0); + + if (peer) { + int n = __atomic_add_unless(&peer->usage, 1, 0); + if (n > 0) + trace_rxrpc_peer(peer, rxrpc_peer_got, n + 1, here); + else + peer = NULL; + } + return peer; +} + +/* + * Queue a peer record. This passes the caller's ref to the workqueue. + */ +void __rxrpc_queue_peer_error(struct rxrpc_peer *peer) +{ + const void *here = __builtin_return_address(0); + int n; + + n = atomic_read(&peer->usage); + if (rxrpc_queue_work(&peer->error_distributor)) + trace_rxrpc_peer(peer, rxrpc_peer_queued_error, n, here); + else + rxrpc_put_peer(peer); +} + +/* + * Discard a peer record. + */ +static void __rxrpc_put_peer(struct rxrpc_peer *peer) { struct rxrpc_net *rxnet = peer->local->rxnet; @@ -402,6 +447,22 @@ void __rxrpc_put_peer(struct rxrpc_peer *peer) kfree_rcu(peer, rcu); } +/* + * Drop a ref on a peer record. + */ +void rxrpc_put_peer(struct rxrpc_peer *peer) +{ + const void *here = __builtin_return_address(0); + int n; + + if (peer) { + n = atomic_dec_return(&peer->usage); + trace_rxrpc_peer(peer, rxrpc_peer_put, n, here); + if (n == 0) + __rxrpc_put_peer(peer); + } +} + /** * rxrpc_kernel_get_peer - Get the peer address of a call * @sock: The socket on which the call is in progress. -- GitLab