Commit 48262608 authored by Tony Lu's avatar Tony Lu Committed by David S. Miller
Browse files

net/smc: Introduce tracepoint for fallback 



This introduces tracepoint for smc fallback to TCP, so that we can track
which connection and why it fallbacks, and map the clcsocks' pointer with
/proc/net/tcp to find more details about TCP connections. Compared with
kprobe or other dynamic tracing, tracepoints are stable and easy to use.

Signed-off-by: default avatarTony Lu <tonylu@linux.alibaba.com>
Reviewed-by: default avatarWen Gu <guwen@linux.alibaba.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 60088891

net/smc/Makefile

+2 −0
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# SPDX-License-Identifier: GPL-2.0-only

ccflags-y += -I$(src)

obj-$(CONFIG_SMC)	+= smc.o

obj-$(CONFIG_SMC_DIAG)	+= smc_diag.o

smc-y := af_smc.o smc_pnet.o smc_ib.o smc_clc.o smc_core.o smc_wr.o smc_llc.o

smc-y += smc_cdc.o smc_tx.o smc_rx.o smc_close.o smc_ism.o smc_netlink.o smc_stats.o

smc-y += smc_tracepoint.o

net/smc/af_smc.c

+2 −0
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@@ -50,6 +50,7 @@ 
#include "smc_rx.h"

#include "smc_close.h"

#include "smc_stats.h"

#include "smc_tracepoint.h"



static DEFINE_MUTEX(smc_server_lgr_pending);	/* serialize link group

						 * creation on server
@@ -564,6 +565,7 @@ static void smc_switch_to_fallback(struct smc_sock *smc, int reason_code) 
	smc->use_fallback = true;

	smc->fallback_rsn = reason_code;

	smc_stat_fallback(smc);

	trace_smc_switch_to_fallback(smc, reason_code);

	if (smc->sk.sk_socket && smc->sk.sk_socket->file) {

		smc->clcsock->file = smc->sk.sk_socket->file;

		smc->clcsock->file->private_data = smc->clcsock;

net/smc/smc_tracepoint.c

0 → 100644
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// SPDX-License-Identifier: GPL-2.0-only



#define CREATE_TRACE_POINTS

#include "smc_tracepoint.h"



EXPORT_TRACEPOINT_SYMBOL(smc_switch_to_fallback);

net/smc/smc_tracepoint.h

0 → 100644
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/* SPDX-License-Identifier: GPL-2.0 */



#undef TRACE_SYSTEM

#define TRACE_SYSTEM smc



#if !defined(_TRACE_SMC_H) || defined(TRACE_HEADER_MULTI_READ)

#define _TRACE_SMC_H



#include <linux/ipv6.h>

#include <linux/tcp.h>

#include <linux/tracepoint.h>

#include <net/ipv6.h>

#include "smc.h"

#include "smc_core.h"



TRACE_EVENT(smc_switch_to_fallback,



	    TP_PROTO(const struct smc_sock *smc, int fallback_rsn),



	    TP_ARGS(smc, fallback_rsn),



	    TP_STRUCT__entry(

			     __field(const void *, sk)

			     __field(const void *, clcsk)

			     __field(int, fallback_rsn)

	    ),



	    TP_fast_assign(

			   const struct sock *sk = &smc->sk;

			   const struct sock *clcsk = smc->clcsock->sk;



			   __entry->sk = sk;

			   __entry->clcsk = clcsk;

			   __entry->fallback_rsn = fallback_rsn;

	    ),



	    TP_printk("sk=%p clcsk=%p fallback_rsn=%d",

		      __entry->sk, __entry->clcsk, __entry->fallback_rsn)

);



#endif /* _TRACE_SMC_H */



#undef TRACE_INCLUDE_PATH

#define TRACE_INCLUDE_PATH .



#undef TRACE_INCLUDE_FILE

#define TRACE_INCLUDE_FILE smc_tracepoint



#include <trace/define_trace.h>