Re: [PATCH net-next v5 1/6] net: tcp: Add trace events for TCP congestion window tracing
From: Masami Hiramatsu <mhiramat@kernel.org>
Date: 2017-12-27 05:43:28
Also in:
linux-sctp, lkml
On Tue, 26 Dec 2017 18:51:55 -0500 (EST) David Miller [off-list ref] wrote:
From: Masami Hiramatsu <mhiramat@kernel.org> Date: Fri, 22 Dec 2017 11:05:33 +0900quoted
This adds an event to trace TCP stat variables with slightly intrusive trace-event. This uses ftrace/perf event log buffer to trace those state, no needs to prepare own ring-buffer, nor custom user apps. User can use ftrace to trace this event as below; # cd /sys/kernel/debug/tracing # echo 1 > events/tcp/tcp_probe/enable (run workloads) # cat trace Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>...quoted
+ TP_fast_assign( + const struct tcp_sock *tp = tcp_sk(sk); + const struct inet_sock *inet = inet_sk(sk); + + memset(__entry->saddr, 0, sizeof(struct sockaddr_in6)); + memset(__entry->daddr, 0, sizeof(struct sockaddr_in6)); + + if (sk->sk_family == AF_INET) { + struct sockaddr_in *v4 = (void *)__entry->saddr; + + v4->sin_family = AF_INET; + v4->sin_port = inet->inet_sport; + v4->sin_addr.s_addr = inet->inet_saddr; + v4 = (void *)__entry->daddr; + v4->sin_family = AF_INET; + v4->sin_port = inet->inet_dport; + v4->sin_addr.s_addr = inet->inet_daddr; +#if IS_ENABLED(CONFIG_IPV6) + } else if (sk->sk_family == AF_INET6) {It looks like doing this ifdef test inside of a trace macro is very undesirable because it upsets sparse. Please see the following commit which just went into 'net'.
OK, that's helpful for me how to avoid it :) I'll update the series . Thank you,
quoted hunk ↗ jump to hunk
==================== commit 6a6b0b9914e73a8a54253dd5f6f5e5dd5e4a756c Author: Mat Martineau [off-list ref] Date: Thu Dec 21 10:29:09 2017 -0800 tcp: Avoid preprocessor directives in tracepoint macro args Using a preprocessor directive to check for CONFIG_IPV6 in the middle of a DECLARE_EVENT_CLASS macro's arg list causes sparse to report a series of errors: ./include/trace/events/tcp.h:68:1: error: directive in argument list ./include/trace/events/tcp.h:75:1: error: directive in argument list ./include/trace/events/tcp.h:144:1: error: directive in argument list ./include/trace/events/tcp.h:151:1: error: directive in argument list ./include/trace/events/tcp.h:216:1: error: directive in argument list ./include/trace/events/tcp.h:223:1: error: directive in argument list ./include/trace/events/tcp.h:274:1: error: directive in argument list ./include/trace/events/tcp.h:281:1: error: directive in argument list Once sparse finds an error, it stops printing warnings for the file it is checking. This masks any sparse warnings that would normally be reported for the core TCP code. Instead, handle the preprocessor conditionals in a couple of auxiliary macros. This also has the benefit of reducing duplicate code. Cc: David Ahern [off-list ref] Signed-off-by: Mat Martineau [off-list ref] Signed-off-by: David S. Miller [off-list ref]diff --git a/include/trace/events/tcp.h b/include/trace/events/tcp.h index 07cccca..ab34c56 100644 --- a/include/trace/events/tcp.h +++ b/include/trace/events/tcp.h@@ -25,6 +25,35 @@ tcp_state_name(TCP_CLOSING), \ tcp_state_name(TCP_NEW_SYN_RECV)) +#define TP_STORE_V4MAPPED(__entry, saddr, daddr) \ + do { \ + struct in6_addr *pin6; \ + \ + pin6 = (struct in6_addr *)__entry->saddr_v6; \ + ipv6_addr_set_v4mapped(saddr, pin6); \ + pin6 = (struct in6_addr *)__entry->daddr_v6; \ + ipv6_addr_set_v4mapped(daddr, pin6); \ + } while (0) + +#if IS_ENABLED(CONFIG_IPV6) +#define TP_STORE_ADDRS(__entry, saddr, daddr, saddr6, daddr6) \ + do { \ + if (sk->sk_family == AF_INET6) { \ + struct in6_addr *pin6; \ + \ + pin6 = (struct in6_addr *)__entry->saddr_v6; \ + *pin6 = saddr6; \ + pin6 = (struct in6_addr *)__entry->daddr_v6; \ + *pin6 = daddr6; \ + } else { \ + TP_STORE_V4MAPPED(__entry, saddr, daddr); \ + } \ + } while (0) +#else +#define TP_STORE_ADDRS(__entry, saddr, daddr, saddr6, daddr6) \ + TP_STORE_V4MAPPED(__entry, saddr, daddr) +#endif + /* * tcp event with arguments sk and skb *@@ -50,7 +79,6 @@ DECLARE_EVENT_CLASS(tcp_event_sk_skb, TP_fast_assign( struct inet_sock *inet = inet_sk(sk); - struct in6_addr *pin6; __be32 *p32; __entry->skbaddr = skb;@@ -65,20 +93,8 @@ DECLARE_EVENT_CLASS(tcp_event_sk_skb, p32 = (__be32 *) __entry->daddr; *p32 = inet->inet_daddr; -#if IS_ENABLED(CONFIG_IPV6) - if (sk->sk_family == AF_INET6) { - pin6 = (struct in6_addr *)__entry->saddr_v6; - *pin6 = sk->sk_v6_rcv_saddr; - pin6 = (struct in6_addr *)__entry->daddr_v6; - *pin6 = sk->sk_v6_daddr; - } else -#endif - { - pin6 = (struct in6_addr *)__entry->saddr_v6; - ipv6_addr_set_v4mapped(inet->inet_saddr, pin6); - pin6 = (struct in6_addr *)__entry->daddr_v6; - ipv6_addr_set_v4mapped(inet->inet_daddr, pin6); - } + TP_STORE_ADDRS(__entry, inet->inet_saddr, inet->inet_daddr, + sk->sk_v6_rcv_saddr, sk->sk_v6_daddr); ), TP_printk("sport=%hu dport=%hu saddr=%pI4 daddr=%pI4 saddrv6=%pI6c daddrv6=%pI6c",@@ -127,7 +143,6 @@ DECLARE_EVENT_CLASS(tcp_event_sk, TP_fast_assign( struct inet_sock *inet = inet_sk(sk); - struct in6_addr *pin6; __be32 *p32; __entry->skaddr = sk;@@ -141,20 +156,8 @@ DECLARE_EVENT_CLASS(tcp_event_sk, p32 = (__be32 *) __entry->daddr; *p32 = inet->inet_daddr; -#if IS_ENABLED(CONFIG_IPV6) - if (sk->sk_family == AF_INET6) { - pin6 = (struct in6_addr *)__entry->saddr_v6; - *pin6 = sk->sk_v6_rcv_saddr; - pin6 = (struct in6_addr *)__entry->daddr_v6; - *pin6 = sk->sk_v6_daddr; - } else -#endif - { - pin6 = (struct in6_addr *)__entry->saddr_v6; - ipv6_addr_set_v4mapped(inet->inet_saddr, pin6); - pin6 = (struct in6_addr *)__entry->daddr_v6; - ipv6_addr_set_v4mapped(inet->inet_daddr, pin6); - } + TP_STORE_ADDRS(__entry, inet->inet_saddr, inet->inet_daddr, + sk->sk_v6_rcv_saddr, sk->sk_v6_daddr); ), TP_printk("sport=%hu dport=%hu saddr=%pI4 daddr=%pI4 saddrv6=%pI6c daddrv6=%pI6c",@@ -197,7 +200,6 @@ TRACE_EVENT(tcp_set_state, TP_fast_assign( struct inet_sock *inet = inet_sk(sk); - struct in6_addr *pin6; __be32 *p32; __entry->skaddr = sk;@@ -213,20 +215,8 @@ TRACE_EVENT(tcp_set_state, p32 = (__be32 *) __entry->daddr; *p32 = inet->inet_daddr; -#if IS_ENABLED(CONFIG_IPV6) - if (sk->sk_family == AF_INET6) { - pin6 = (struct in6_addr *)__entry->saddr_v6; - *pin6 = sk->sk_v6_rcv_saddr; - pin6 = (struct in6_addr *)__entry->daddr_v6; - *pin6 = sk->sk_v6_daddr; - } else -#endif - { - pin6 = (struct in6_addr *)__entry->saddr_v6; - ipv6_addr_set_v4mapped(inet->inet_saddr, pin6); - pin6 = (struct in6_addr *)__entry->daddr_v6; - ipv6_addr_set_v4mapped(inet->inet_daddr, pin6); - } + TP_STORE_ADDRS(__entry, inet->inet_saddr, inet->inet_daddr, + sk->sk_v6_rcv_saddr, sk->sk_v6_daddr); ), TP_printk("sport=%hu dport=%hu saddr=%pI4 daddr=%pI4 saddrv6=%pI6c daddrv6=%pI6c oldstate=%s newstate=%s",@@ -256,7 +246,6 @@ TRACE_EVENT(tcp_retransmit_synack, TP_fast_assign( struct inet_request_sock *ireq = inet_rsk(req); - struct in6_addr *pin6; __be32 *p32; __entry->skaddr = sk;@@ -271,20 +260,8 @@ TRACE_EVENT(tcp_retransmit_synack, p32 = (__be32 *) __entry->daddr; *p32 = ireq->ir_rmt_addr; -#if IS_ENABLED(CONFIG_IPV6) - if (sk->sk_family == AF_INET6) { - pin6 = (struct in6_addr *)__entry->saddr_v6; - *pin6 = ireq->ir_v6_loc_addr; - pin6 = (struct in6_addr *)__entry->daddr_v6; - *pin6 = ireq->ir_v6_rmt_addr; - } else -#endif - { - pin6 = (struct in6_addr *)__entry->saddr_v6; - ipv6_addr_set_v4mapped(ireq->ir_loc_addr, pin6); - pin6 = (struct in6_addr *)__entry->daddr_v6; - ipv6_addr_set_v4mapped(ireq->ir_rmt_addr, pin6); - } + TP_STORE_ADDRS(__entry, ireq->ir_loc_addr, ireq->ir_rmt_addr, + ireq->ir_v6_loc_addr, ireq->ir_v6_rmt_addr); ), TP_printk("sport=%hu dport=%hu saddr=%pI4 daddr=%pI4 saddrv6=%pI6c daddrv6=%pI6c",
-- Masami Hiramatsu [off-list ref]