From 15f661dc95daec9b38e8e4cc931c95afe0ae0cef Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 10 Oct 2022 15:51:39 +0100 Subject: [PATCH] rxrpc: Implement a mechanism to send an event notification to a call Provide a means by which an event notification can be sent to a call such that the I/O thread can process it rather than it being done in a separate workqueue. This will allow a lot of locking to be removed. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org --- include/trace/events/rxrpc.h | 52 ++++++++++++++++++++++++++++++++++++ net/rxrpc/ar-internal.h | 5 +++- net/rxrpc/call_object.c | 24 +++++++++++++++++ net/rxrpc/input.c | 3 +-- net/rxrpc/io_thread.c | 20 ++++++++++++-- net/rxrpc/local_object.c | 1 + 6 files changed, 100 insertions(+), 5 deletions(-) diff --git a/include/trace/events/rxrpc.h b/include/trace/events/rxrpc.h index 44a9be9836f9..0b12d96c7921 100644 --- a/include/trace/events/rxrpc.h +++ b/include/trace/events/rxrpc.h @@ -16,6 +16,13 @@ /* * Declare tracing information enums and their string mappings for display. */ +#define rxrpc_call_poke_traces \ + EM(rxrpc_call_poke_error, "Error") \ + EM(rxrpc_call_poke_idle, "Idle") \ + EM(rxrpc_call_poke_start, "Start") \ + EM(rxrpc_call_poke_timer, "Timer") \ + E_(rxrpc_call_poke_timer_now, "Timer-now") + #define rxrpc_skb_traces \ EM(rxrpc_skb_eaten_by_unshare, "ETN unshare ") \ EM(rxrpc_skb_eaten_by_unshare_nomem, "ETN unshar-nm") \ @@ -150,6 +157,7 @@ EM(rxrpc_call_get_input, "GET input ") \ EM(rxrpc_call_get_kernel_service, "GET krnl-srv") \ EM(rxrpc_call_get_notify_socket, "GET notify ") \ + EM(rxrpc_call_get_poke, "GET poke ") \ EM(rxrpc_call_get_recvmsg, "GET recvmsg ") \ EM(rxrpc_call_get_release_sock, "GET rel-sock") \ EM(rxrpc_call_get_sendmsg, "GET sendmsg ") \ @@ -160,6 +168,7 @@ EM(rxrpc_call_put_discard_prealloc, "PUT disc-pre") \ EM(rxrpc_call_put_input, "PUT input ") \ EM(rxrpc_call_put_kernel, "PUT kernel ") \ + EM(rxrpc_call_put_poke, "PUT poke ") \ EM(rxrpc_call_put_recvmsg, "PUT recvmsg ") \ EM(rxrpc_call_put_release_sock, "PUT rls-sock") \ EM(rxrpc_call_put_release_sock_tba, "PUT rls-sk-a") \ @@ -378,6 +387,7 @@ #define E_(a, b) a enum rxrpc_bundle_trace { rxrpc_bundle_traces } __mode(byte); +enum rxrpc_call_poke_trace { rxrpc_call_poke_traces } __mode(byte); enum rxrpc_call_trace { rxrpc_call_traces } __mode(byte); enum rxrpc_client_trace { rxrpc_client_traces } __mode(byte); enum rxrpc_congest_change { rxrpc_congest_changes } __mode(byte); @@ -408,6 +418,7 @@ enum rxrpc_txqueue_trace { rxrpc_txqueue_traces } __mode(byte); #define E_(a, b) TRACE_DEFINE_ENUM(a); rxrpc_bundle_traces; +rxrpc_call_poke_traces; rxrpc_call_traces; rxrpc_client_traces; rxrpc_congest_changes; @@ -1747,6 +1758,47 @@ TRACE_EVENT(rxrpc_txbuf, __entry->ref) ); +TRACE_EVENT(rxrpc_poke_call, + TP_PROTO(struct rxrpc_call *call, bool busy, + enum rxrpc_call_poke_trace what), + + TP_ARGS(call, busy, what), + + TP_STRUCT__entry( + __field(unsigned int, call_debug_id ) + __field(bool, busy ) + __field(enum rxrpc_call_poke_trace, what ) + ), + + TP_fast_assign( + __entry->call_debug_id = call->debug_id; + __entry->busy = busy; + __entry->what = what; + ), + + TP_printk("c=%08x %s%s", + __entry->call_debug_id, + __print_symbolic(__entry->what, rxrpc_call_poke_traces), + __entry->busy ? "!" : "") + ); + +TRACE_EVENT(rxrpc_call_poked, + TP_PROTO(struct rxrpc_call *call), + + TP_ARGS(call), + + TP_STRUCT__entry( + __field(unsigned int, call_debug_id ) + ), + + TP_fast_assign( + __entry->call_debug_id = call->debug_id; + ), + + TP_printk("c=%08x", + __entry->call_debug_id) + ); + #undef EM #undef E_ #endif /* _TRACE_RXRPC_H */ diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h index 654e9dab107c..a80655fa9dfb 100644 --- a/net/rxrpc/ar-internal.h +++ b/net/rxrpc/ar-internal.h @@ -292,6 +292,7 @@ struct rxrpc_local { struct sk_buff_head reject_queue; /* packets awaiting rejection */ struct sk_buff_head event_queue; /* endpoint event packets awaiting processing */ struct sk_buff_head rx_queue; /* Received packets */ + struct list_head call_attend_q; /* Calls requiring immediate attention */ struct rb_root client_bundles; /* Client connection bundles by socket params */ spinlock_t client_bundles_lock; /* Lock for client_bundles */ spinlock_t lock; /* access lock */ @@ -616,6 +617,7 @@ struct rxrpc_call { struct list_head recvmsg_link; /* Link in rx->recvmsg_q */ struct list_head sock_link; /* Link in rx->sock_calls */ struct rb_node sock_node; /* Node in rx->calls */ + struct list_head attend_link; /* Link in local->call_attend_q */ struct rxrpc_txbuf *tx_pending; /* Tx buffer being filled */ wait_queue_head_t waitq; /* Wait queue for channel or Tx */ s64 tx_total_len; /* Total length left to be transmitted (or -1) */ @@ -843,6 +845,7 @@ extern const char *const rxrpc_call_states[]; extern const char *const rxrpc_call_completions[]; extern struct kmem_cache *rxrpc_call_jar; +void rxrpc_poke_call(struct rxrpc_call *call, enum rxrpc_call_poke_trace what); struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *, unsigned long); struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *, gfp_t, unsigned int); struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *, @@ -951,7 +954,7 @@ void rxrpc_unpublish_service_conn(struct rxrpc_connection *); /* * input.c */ -void rxrpc_input_call_packet(struct rxrpc_call *, struct sk_buff *); +void rxrpc_input_call_event(struct rxrpc_call *, struct sk_buff *); void rxrpc_input_implicit_end_call(struct rxrpc_sock *, struct rxrpc_connection *, struct rxrpc_call *); diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c index f6d1b3a6f8c6..997641e3d1c8 100644 --- a/net/rxrpc/call_object.c +++ b/net/rxrpc/call_object.c @@ -45,6 +45,29 @@ static struct semaphore rxrpc_call_limiter = static struct semaphore rxrpc_kernel_call_limiter = __SEMAPHORE_INITIALIZER(rxrpc_kernel_call_limiter, 1000); +void rxrpc_poke_call(struct rxrpc_call *call, enum rxrpc_call_poke_trace what) +{ + struct rxrpc_local *local; + struct rxrpc_peer *peer = call->peer; + bool busy; + + if (WARN_ON_ONCE(!peer)) + return; + local = peer->local; + + if (call->state < RXRPC_CALL_COMPLETE) { + spin_lock_bh(&local->lock); + busy = !list_empty(&call->attend_link); + trace_rxrpc_poke_call(call, busy, what); + if (!busy) { + rxrpc_get_call(call, rxrpc_call_get_poke); + list_add_tail(&call->attend_link, &local->call_attend_q); + } + spin_unlock_bh(&local->lock); + rxrpc_wake_up_io_thread(local); + } +} + static void rxrpc_call_timer_expired(struct timer_list *t) { struct rxrpc_call *call = from_timer(call, t, timer); @@ -137,6 +160,7 @@ struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp, INIT_LIST_HEAD(&call->accept_link); INIT_LIST_HEAD(&call->recvmsg_link); INIT_LIST_HEAD(&call->sock_link); + INIT_LIST_HEAD(&call->attend_link); INIT_LIST_HEAD(&call->tx_buffer); skb_queue_head_init(&call->recvmsg_queue); skb_queue_head_init(&call->rx_oos_queue); diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c index 13c52145a926..036f02371051 100644 --- a/net/rxrpc/input.c +++ b/net/rxrpc/input.c @@ -1017,8 +1017,7 @@ static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb) /* * Process an incoming call packet. */ -void rxrpc_input_call_packet(struct rxrpc_call *call, - struct sk_buff *skb) +void rxrpc_input_call_event(struct rxrpc_call *call, struct sk_buff *skb) { struct rxrpc_skb_priv *sp = rxrpc_skb(skb); unsigned long timo; diff --git a/net/rxrpc/io_thread.c b/net/rxrpc/io_thread.c index 416c6101cf78..cc249bc6b8cd 100644 --- a/net/rxrpc/io_thread.c +++ b/net/rxrpc/io_thread.c @@ -366,7 +366,7 @@ static int rxrpc_input_packet(struct rxrpc_local *local, struct sk_buff *skb) /* Process a call packet; this either discards or passes on the ref * elsewhere. */ - rxrpc_input_call_packet(call, skb); + rxrpc_input_call_event(call, skb); goto out; discard: @@ -413,6 +413,7 @@ int rxrpc_io_thread(void *data) { struct sk_buff_head rx_queue; struct rxrpc_local *local = data; + struct rxrpc_call *call; struct sk_buff *skb; skb_queue_head_init(&rx_queue); @@ -422,6 +423,20 @@ int rxrpc_io_thread(void *data) for (;;) { rxrpc_inc_stat(local->rxnet, stat_io_loop); + /* Deal with calls that want immediate attention. */ + if ((call = list_first_entry_or_null(&local->call_attend_q, + struct rxrpc_call, + attend_link))) { + spin_lock_bh(&local->lock); + list_del_init(&call->attend_link); + spin_unlock_bh(&local->lock); + + trace_rxrpc_call_poked(call); + rxrpc_input_call_event(call, NULL); + rxrpc_put_call(call, rxrpc_call_put_poke); + continue; + } + /* Process received packets and errors. */ if ((skb = __skb_dequeue(&rx_queue))) { switch (skb->mark) { @@ -450,7 +465,8 @@ int rxrpc_io_thread(void *data) } set_current_state(TASK_INTERRUPTIBLE); - if (!skb_queue_empty(&local->rx_queue)) { + if (!skb_queue_empty(&local->rx_queue) || + !list_empty(&local->call_attend_q)) { __set_current_state(TASK_RUNNING); continue; } diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c index 6b4d77219f36..03f491cc23ef 100644 --- a/net/rxrpc/local_object.c +++ b/net/rxrpc/local_object.c @@ -104,6 +104,7 @@ static struct rxrpc_local *rxrpc_alloc_local(struct rxrpc_net *rxnet, skb_queue_head_init(&local->reject_queue); skb_queue_head_init(&local->event_queue); skb_queue_head_init(&local->rx_queue); + INIT_LIST_HEAD(&local->call_attend_q); local->client_bundles = RB_ROOT; spin_lock_init(&local->client_bundles_lock); spin_lock_init(&local->lock);