From af094824f20b454ee23b7b5a860b3ba58f4e6938 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 17 Oct 2022 08:54:57 +0100 Subject: rxrpc: Allow a delay to be injected into packet reception If CONFIG_AF_RXRPC_DEBUG_RX_DELAY=y, then a delay is injected between packets and errors being received and them being made available to the processing code, thereby allowing the RTT to be artificially increased. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org --- net/rxrpc/io_thread.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 47 insertions(+), 1 deletion(-) (limited to 'net/rxrpc/io_thread.c') diff --git a/net/rxrpc/io_thread.c b/net/rxrpc/io_thread.c index 9e9dfb2fc559..4a3a08a0e2cd 100644 --- a/net/rxrpc/io_thread.c +++ b/net/rxrpc/io_thread.c @@ -25,6 +25,7 @@ static int rxrpc_input_packet_on_conn(struct rxrpc_connection *conn, */ int rxrpc_encap_rcv(struct sock *udp_sk, struct sk_buff *skb) { + struct sk_buff_head *rx_queue; struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk); if (unlikely(!local)) { @@ -36,7 +37,16 @@ int rxrpc_encap_rcv(struct sock *udp_sk, struct sk_buff *skb) skb->mark = RXRPC_SKB_MARK_PACKET; rxrpc_new_skb(skb, rxrpc_skb_new_encap_rcv); - skb_queue_tail(&local->rx_queue, skb); + rx_queue = &local->rx_queue; +#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY + if (rxrpc_inject_rx_delay || + !skb_queue_empty(&local->rx_delay_queue)) { + skb->tstamp = ktime_add_ms(skb->tstamp, rxrpc_inject_rx_delay); + rx_queue = &local->rx_delay_queue; + } +#endif + + skb_queue_tail(rx_queue, skb); rxrpc_wake_up_io_thread(local); return 0; } @@ -407,6 +417,9 @@ int rxrpc_io_thread(void *data) struct rxrpc_local *local = data; struct rxrpc_call *call; struct sk_buff *skb; +#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY + ktime_t now; +#endif bool should_stop; complete(&local->io_thread_ready); @@ -481,6 +494,17 @@ int rxrpc_io_thread(void *data) continue; } + /* Inject a delay into packets if requested. */ +#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY + now = ktime_get_real(); + while ((skb = skb_peek(&local->rx_delay_queue))) { + if (ktime_before(now, skb->tstamp)) + break; + skb = skb_dequeue(&local->rx_delay_queue); + skb_queue_tail(&local->rx_queue, skb); + } +#endif + if (!skb_queue_empty(&local->rx_queue)) { spin_lock_irq(&local->rx_queue.lock); skb_queue_splice_tail_init(&local->rx_queue, &rx_queue); @@ -502,6 +526,28 @@ int rxrpc_io_thread(void *data) if (should_stop) break; + +#ifdef CONFIG_AF_RXRPC_INJECT_RX_DELAY + skb = skb_peek(&local->rx_delay_queue); + if (skb) { + unsigned long timeout; + ktime_t tstamp = skb->tstamp; + ktime_t now = ktime_get_real(); + s64 delay_ns = ktime_to_ns(ktime_sub(tstamp, now)); + + if (delay_ns <= 0) { + __set_current_state(TASK_RUNNING); + continue; + } + + timeout = nsecs_to_jiffies(delay_ns); + timeout = max(timeout, 1UL); + schedule_timeout(timeout); + __set_current_state(TASK_RUNNING); + continue; + } +#endif + schedule(); } -- cgit v1.2.3