From 71f3ca408fd43b586c02480768a503af075b247e Mon Sep 17 00:00:00 2001 From: David Howells Date: Sat, 17 Sep 2016 10:49:14 +0100 Subject: rxrpc: Improve skb tracing Improve sk_buff tracing within AF_RXRPC by the following means: (1) Use an enum to note the event type rather than plain integers and use an array of event names rather than a big multi ?: list. (2) Distinguish Rx from Tx packets and account them separately. This requires the call phase to be tracked so that we know what we might find in rxtx_buffer[]. (3) Add a parameter to rxrpc_{new,see,get,free}_skb() to indicate the event type. (4) A pair of 'rotate' events are added to indicate packets that are about to be rotated out of the Rx and Tx windows. (5) A pair of 'lost' events are added, along with rxrpc_lose_skb() for packet loss injection recording. Signed-off-by: David Howells --- net/rxrpc/skbuff.c | 53 ++++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 38 insertions(+), 15 deletions(-) (limited to 'net/rxrpc/skbuff.c') diff --git a/net/rxrpc/skbuff.c b/net/rxrpc/skbuff.c index 620d9ccaf3c1..5154cbf7e540 100644 --- a/net/rxrpc/skbuff.c +++ b/net/rxrpc/skbuff.c @@ -18,54 +18,76 @@ #include #include "ar-internal.h" +#define select_skb_count(op) (op >= rxrpc_skb_tx_cleaned ? &rxrpc_n_tx_skbs : &rxrpc_n_rx_skbs) + /* - * Note the existence of a new-to-us socket buffer (allocated or dequeued). + * Note the allocation or reception of a socket buffer. */ -void rxrpc_new_skb(struct sk_buff *skb) +void rxrpc_new_skb(struct sk_buff *skb, enum rxrpc_skb_trace op) { const void *here = __builtin_return_address(0); - int n = atomic_inc_return(&rxrpc_n_skbs); - trace_rxrpc_skb(skb, 0, atomic_read(&skb->users), n, here); + int n = atomic_inc_return(select_skb_count(op)); + trace_rxrpc_skb(skb, op, atomic_read(&skb->users), n, here); } /* * Note the re-emergence of a socket buffer from a queue or buffer. */ -void rxrpc_see_skb(struct sk_buff *skb) +void rxrpc_see_skb(struct sk_buff *skb, enum rxrpc_skb_trace op) { const void *here = __builtin_return_address(0); if (skb) { - int n = atomic_read(&rxrpc_n_skbs); - trace_rxrpc_skb(skb, 1, atomic_read(&skb->users), n, here); + int n = atomic_read(select_skb_count(op)); + trace_rxrpc_skb(skb, op, atomic_read(&skb->users), n, here); } } /* * Note the addition of a ref on a socket buffer. */ -void rxrpc_get_skb(struct sk_buff *skb) +void rxrpc_get_skb(struct sk_buff *skb, enum rxrpc_skb_trace op) { const void *here = __builtin_return_address(0); - int n = atomic_inc_return(&rxrpc_n_skbs); - trace_rxrpc_skb(skb, 2, atomic_read(&skb->users), n, here); + int n = atomic_inc_return(select_skb_count(op)); + trace_rxrpc_skb(skb, op, atomic_read(&skb->users), n, here); skb_get(skb); } /* * Note the destruction of a socket buffer. */ -void rxrpc_free_skb(struct sk_buff *skb) +void rxrpc_free_skb(struct sk_buff *skb, enum rxrpc_skb_trace op) { const void *here = __builtin_return_address(0); if (skb) { int n; CHECK_SLAB_OKAY(&skb->users); - n = atomic_dec_return(&rxrpc_n_skbs); - trace_rxrpc_skb(skb, 3, atomic_read(&skb->users), n, here); + n = atomic_dec_return(select_skb_count(op)); + trace_rxrpc_skb(skb, op, atomic_read(&skb->users), n, here); kfree_skb(skb); } } +/* + * Note the injected loss of a socket buffer. + */ +void rxrpc_lose_skb(struct sk_buff *skb, enum rxrpc_skb_trace op) +{ + const void *here = __builtin_return_address(0); + if (skb) { + int n; + CHECK_SLAB_OKAY(&skb->users); + if (op == rxrpc_skb_tx_lost) { + n = atomic_read(select_skb_count(op)); + trace_rxrpc_skb(skb, op, atomic_read(&skb->users), n, here); + } else { + n = atomic_dec_return(select_skb_count(op)); + trace_rxrpc_skb(skb, op, atomic_read(&skb->users), n, here); + kfree_skb(skb); + } + } +} + /* * Clear a queue of socket buffers. */ @@ -74,8 +96,9 @@ void rxrpc_purge_queue(struct sk_buff_head *list) const void *here = __builtin_return_address(0); struct sk_buff *skb; while ((skb = skb_dequeue((list))) != NULL) { - int n = atomic_dec_return(&rxrpc_n_skbs); - trace_rxrpc_skb(skb, 4, atomic_read(&skb->users), n, here); + int n = atomic_dec_return(select_skb_count(rxrpc_skb_rx_purged)); + trace_rxrpc_skb(skb, rxrpc_skb_rx_purged, + atomic_read(&skb->users), n, here); kfree_skb(skb); } } -- cgit v1.2.3