X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=include%2Flttng%2Ftracepoint.h;h=01561d81f4bebe62c7f4df35accb62504baaf681;hb=167ff4df850ed5c954ee374db66a04b1c9a4ef34;hp=6e1026dc4a0449140b74112b9054a250f76b4608;hpb=b43de1e7d359eb990921781c6c3e4eea31c4c4bd;p=lttng-ust.git diff --git a/include/lttng/tracepoint.h b/include/lttng/tracepoint.h index 6e1026dc..01561d81 100644 --- a/include/lttng/tracepoint.h +++ b/include/lttng/tracepoint.h @@ -1,216 +1,331 @@ -#ifndef _UST_TRACEPOINT_H -#define _UST_TRACEPOINT_H +#ifndef _LTTNG_TRACEPOINT_H +#define _LTTNG_TRACEPOINT_H /* - * Copyright (C) 2008-2011 Mathieu Desnoyers - * Copyright (C) 2009 Pierre-Marc Fournier - * Copyright (C) 2009 Steven Rostedt + * Copyright 2011-2012 - Mathieu Desnoyers * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; - * version 2.1 of the License. + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: * - * This library is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this library; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA - * - * Heavily inspired from the Linux Kernel Markers. - * - * Ported to userspace by Pierre-Marc Fournier. + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. */ -#include -#include +#include +#include +#include +#include /* for dlopen */ +#include /* for memset */ +#include +#include /* for sdt */ + +#ifdef LTTNG_UST_HAVE_SDT_INTEGRATION +#define SDT_USE_VARIADIC +#include +#else +#define STAP_PROBEV(...) +#endif #ifdef __cplusplus extern "C" { #endif -struct tracepoint_probe { - void *func; - void *data; -}; +#define tracepoint(provider, name, ...) \ + do { \ + STAP_PROBEV(provider, name, ## __VA_ARGS__); \ + if (caa_unlikely(__tracepoint_##provider##___##name.state)) \ + __tracepoint_cb_##provider##___##name(__VA_ARGS__); \ + } while (0) -struct tracepoint { - const char *name; /* Tracepoint name */ - char state; /* State. */ - struct tracepoint_probe *probes; -}; +#define TP_ARGS(...) __VA_ARGS__ /* - * Tracepoints should be added to the instrumented code using the - * "tracepoint()" macro. + * TP_ARGS takes tuples of type, argument separated by a comma. + * It can take up to 10 tuples (which means that less than 10 tuples is + * fine too). + * Each tuple is also separated by a comma. */ -#define tracepoint(provider, name, args...) \ - __trace_##provider##___##name(args) +#define __TP_COMBINE_TOKENS(_tokena, _tokenb) \ + _tokena##_tokenb +#define _TP_COMBINE_TOKENS(_tokena, _tokenb) \ + __TP_COMBINE_TOKENS(_tokena, _tokenb) +#define __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \ + _tokena##_tokenb##_tokenc +#define _TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \ + __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) +#define __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \ + _tokena##_tokenb##_tokenc##_tokend +#define _TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \ + __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) /* - * it_func[0] is never NULL because there is at least one element in the array - * when the array itself is non NULL. + * _TP_EXVAR* extract the var names. + * _TP_EXVAR1 and _TP_EXDATA_VAR1 are needed for -std=c99. */ -#define __DO_TRACE(tp, proto, args) \ - do { \ - struct tracepoint_probe *__tp_it_probe_ptr; \ - void *__tp_it_func; \ - void *__tp_cb_data; \ - \ - rcu_read_lock(); \ - __tp_it_probe_ptr = rcu_dereference((tp)->probes); \ - if (__tp_it_probe_ptr) { \ - do { \ - __tp_it_func = __tp_it_probe_ptr->func; \ - __tp_cb_data = __tp_it_probe_ptr->data; \ - URCU_FORCE_CAST(void(*)(proto), __tp_it_func)(args); \ - } while ((++__tp_it_probe_ptr)->func); \ - } \ - rcu_read_unlock(); \ - } while (0) - -#define TP_PARAMS(args...) args -#define TP_PROTO(args...) args -#define TP_ARGS(args...) args - -#define __CHECK_TRACE(provider, name, proto, args) \ - do { \ - if (caa_unlikely(__tracepoint_##provider##___##name.state)) \ - __DO_TRACE(&__tracepoint_##provider##___##name, \ - TP_PROTO(proto), TP_ARGS(args)); \ - } while (0) +#define _TP_EXVAR0() +#define _TP_EXVAR1(a) +#define _TP_EXVAR2(a,b) b +#define _TP_EXVAR4(a,b,c,d) b,d +#define _TP_EXVAR6(a,b,c,d,e,f) b,d,f +#define _TP_EXVAR8(a,b,c,d,e,f,g,h) b,d,f,h +#define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j) b,d,f,h,j +#define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l) b,d,f,h,j,l +#define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) b,d,f,h,j,l,n +#define _TP_EXVAR16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) b,d,f,h,j,l,n,p +#define _TP_EXVAR18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) b,d,f,h,j,l,n,p,r +#define _TP_EXVAR20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) b,d,f,h,j,l,n,p,r,t + +#define _TP_EXDATA_VAR0() __tp_data +#define _TP_EXDATA_VAR1(a) __tp_data +#define _TP_EXDATA_VAR2(a,b) __tp_data,b +#define _TP_EXDATA_VAR4(a,b,c,d) __tp_data,b,d +#define _TP_EXDATA_VAR6(a,b,c,d,e,f) __tp_data,b,d,f +#define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h) __tp_data,b,d,f,h +#define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j) __tp_data,b,d,f,h,j +#define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l) __tp_data,b,d,f,h,j,l +#define _TP_EXDATA_VAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) __tp_data,b,d,f,h,j,l,n +#define _TP_EXDATA_VAR16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) __tp_data,b,d,f,h,j,l,n,p +#define _TP_EXDATA_VAR18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) __tp_data,b,d,f,h,j,l,n,p,r +#define _TP_EXDATA_VAR20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) __tp_data,b,d,f,h,j,l,n,p,r,t /* - * Make sure the alignment of the structure in the __tracepoints section will - * not add unwanted padding between the beginning of the section and the - * structure. Force alignment to the same alignment as the section start. + * _TP_EXPROTO* extract tuples of type, var. + * _TP_EXPROTO1 and _TP_EXDATA_PROTO1 are needed for -std=c99. */ -#define __DECLARE_TRACEPOINT(provider, name, proto, args, data_proto, data_args) \ - extern struct tracepoint __tracepoint_##provider##___##name; \ - static inline void __trace_##provider##___##name(proto) \ - { \ - __CHECK_TRACE(provider, name, TP_PROTO(data_proto), \ - TP_ARGS(data_args)); \ - } \ - static inline int \ - __register_trace_##provider##___##name(void (*probe)(data_proto), void *data) \ - { \ - return __tracepoint_probe_register(#provider ":" #name, (void *) probe, \ - data); \ - } \ - static inline int \ - __unregister_trace_##provider##___##name(void (*probe)(data_proto), void *data) \ - { \ - return __tracepoint_probe_unregister(#provider ":" #name, (void *) probe, \ - data); \ - } +#define _TP_EXPROTO0() void +#define _TP_EXPROTO1(a) void +#define _TP_EXPROTO2(a,b) a b +#define _TP_EXPROTO4(a,b,c,d) a b,c d +#define _TP_EXPROTO6(a,b,c,d,e,f) a b,c d,e f +#define _TP_EXPROTO8(a,b,c,d,e,f,g,h) a b,c d,e f,g h +#define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j) a b,c d,e f,g h,i j +#define _TP_EXPROTO12(a,b,c,d,e,f,g,h,i,j,k,l) a b,c d,e f,g h,i j,k l +#define _TP_EXPROTO14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) a b,c d,e f,g h,i j,k l,m n +#define _TP_EXPROTO16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) a b,c d,e f,g h,i j,k l,m n,o p +#define _TP_EXPROTO18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) a b,c d,e f,g h,i j,k l,m n,o p,q r +#define _TP_EXPROTO20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) a b,c d,e f,g h,i j,k l,m n,o p,q r,s t + +#define _TP_EXDATA_PROTO0() void *__tp_data +#define _TP_EXDATA_PROTO1(a) void *__tp_data +#define _TP_EXDATA_PROTO2(a,b) void *__tp_data,a b +#define _TP_EXDATA_PROTO4(a,b,c,d) void *__tp_data,a b,c d +#define _TP_EXDATA_PROTO6(a,b,c,d,e,f) void *__tp_data,a b,c d,e f +#define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h) void *__tp_data,a b,c d,e f,g h +#define _TP_EXDATA_PROTO10(a,b,c,d,e,f,g,h,i,j) void *__tp_data,a b,c d,e f,g h,i j +#define _TP_EXDATA_PROTO12(a,b,c,d,e,f,g,h,i,j,k,l) void *__tp_data,a b,c d,e f,g h,i j,k l +#define _TP_EXDATA_PROTO14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) void *__tp_data,a b,c d,e f,g h,i j,k l,m n +#define _TP_EXDATA_PROTO16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p +#define _TP_EXDATA_PROTO18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p,q r +#define _TP_EXDATA_PROTO20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p,q r,s t + +/* Preprocessor trick to count arguments. Inspired from sdt.h. */ +#define _TP_NARGS(...) __TP_NARGS(__VA_ARGS__, 20,19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0) +#define __TP_NARGS(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20, N, ...) N +#define _TP_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__)) +#define _TP_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__)) +#define _TP_DATA_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__)) +#define _TP_DATA_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__)) +#define _TP_ARGS_PROTO(...) _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__) +#define _TP_ARGS_VAR(...) _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__) +#define _TP_ARGS_DATA_PROTO(...) _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__) +#define _TP_ARGS_DATA_VAR(...) _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__) +#define _TP_PARAMS(...) __VA_ARGS__ + +#define _DECLARE_TRACEPOINT(_provider, _name, ...) \ +extern struct tracepoint __tracepoint_##_provider##___##_name; \ +static inline void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \ +{ \ + struct tracepoint_probe *__tp_probe; \ + \ + if (!TP_RCU_LINK_TEST()) \ + return; \ + tp_rcu_read_lock_bp(); \ + __tp_probe = tp_rcu_dereference_bp(__tracepoint_##_provider##___##_name.probes); \ + if (caa_unlikely(!__tp_probe)) \ + goto end; \ + do { \ + void (*__tp_cb)(void) = __tp_probe->func; \ + void *__tp_data = __tp_probe->data; \ + \ + URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb) \ + (_TP_ARGS_DATA_VAR(__VA_ARGS__)); \ + } while ((++__tp_probe)->func); \ +end: \ + tp_rcu_read_unlock_bp(); \ +} \ +static inline void __tracepoint_register_##_provider##___##_name(char *name, \ + void (*func)(void), void *data) \ +{ \ + __tracepoint_probe_register(name, func, data, \ + __tracepoint_##_provider##___##_name.signature); \ +} \ +static inline void __tracepoint_unregister_##_provider##___##_name(char *name, \ + void (*func)(void), void *data) \ +{ \ + __tracepoint_probe_unregister(name, func, data); \ +} + +extern int __tracepoint_probe_register(const char *name, void (*func)(void), + void *data, const char *signature); +extern int __tracepoint_probe_unregister(const char *name, void (*func)(void), + void *data); /* - * The need for the _DECLARE_TRACEPOINT_NOARGS() is to handle the prototype - * (void). "void" is a special value in a function prototype and can - * not be combined with other arguments. Since the DECLARE_TRACEPOINT() - * macro adds a data element at the beginning of the prototype, - * we need a way to differentiate "(void *data, proto)" from - * "(void *data, void)". The second prototype is invalid. - * - * DECLARE_TRACEPOINT_NOARGS() passes "void" as the tracepoint prototype - * and "void *__tp_cb_data" as the callback prototype. - * - * DECLARE_TRACEPOINT() passes "proto" as the tracepoint protoype and - * "void *__tp_cb_data, proto" as the callback prototype. + * tracepoint dynamic linkage handling (callbacks). Hidden visibility: + * shared across objects in a module/main executable. */ -#define _DECLARE_TRACEPOINT_NOARGS(provider, name) \ - __DECLARE_TRACEPOINT(provider, name, void, , void *__tp_cb_data, __tp_cb_data) +struct tracepoint_dlopen { + void *liblttngust_handle; + + int (*tracepoint_register_lib)(struct tracepoint * const *tracepoints_start, + int tracepoints_count); + int (*tracepoint_unregister_lib)(struct tracepoint * const *tracepoints_start); +#ifndef _LGPL_SOURCE + void (*rcu_read_lock_sym_bp)(void); + void (*rcu_read_unlock_sym_bp)(void); + void *(*rcu_dereference_sym_bp)(void *p); +#endif +}; -#define _DECLARE_TRACEPOINT(provider, name, proto, args) \ - __DECLARE_TRACEPOINT(provider, name, TP_PARAMS(proto), TP_PARAMS(args), \ - TP_PARAMS(void *__tp_cb_data, proto), \ - TP_PARAMS(__tp_cb_data, args)) +extern struct tracepoint_dlopen tracepoint_dlopen; -/* - * __tracepoints_ptrs section is not const (read-only) to let the linker update - * the pointer, allowing PIC code. - */ -#define _DEFINE_TRACEPOINT(provider, name) \ - static const char __tpstrtab_##provider##___##name[] \ - __attribute__((section("__tracepoints_strings"))) = \ - #provider ":" #name; \ - struct tracepoint __tracepoint_##provider##___##name \ - __attribute__((section("__tracepoints"))) = \ - { __tpstrtab_##provider##___##name, 0, NULL }; \ - static struct tracepoint * __tracepoint_ptr_##provider##___##name \ - __attribute__((used, section("__tracepoints_ptrs"))) = \ - &__tracepoint_##provider##___##name; - - -#define __register_tracepoint(provider, name, probe, data) \ - __register_trace_##provider##___##name(probe, data) -#define __unregister_tracepoint(provider, name, probe, data) \ - __unregister_trace_##provider##___##name(probe, data) +#ifdef TRACEPOINT_DEFINE /* - * Connect a probe to a tracepoint. - * Internal API. + * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a + * unresolved symbol that requires the provider to be linked in. When + * TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an + * unresolved symbol that depends on having the provider linked in, + * otherwise the linker complains. This deals with use of static + * libraries, ensuring that the linker does not remove the provider + * object from the executable. */ -extern -int __tracepoint_probe_register(const char *name, void *probe, void *data); +#ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE +#define _TRACEPOINT_UNDEFINED_REF(provider) NULL +#else /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */ +#define _TRACEPOINT_UNDEFINED_REF(provider) &__tracepoint_provider_##provider +#endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */ /* - * Disconnect a probe from a tracepoint. - * Internal API. + * Note: to allow PIC code, we need to allow the linker to update the pointers + * in the __tracepoints_ptrs section. + * Therefore, this section is _not_ const (read-only). */ -extern -int __tracepoint_probe_unregister(const char *name, void *probe, void *data); +#define _TP_EXTRACT_STRING(...) #__VA_ARGS__ + +#define _DEFINE_TRACEPOINT(_provider, _name, _args) \ + extern int __tracepoint_provider_##_provider; \ + static const char __tp_strtab_##_provider##___##_name[] \ + __attribute__((section("__tracepoints_strings"))) = \ + #_provider ":" #_name; \ + struct tracepoint __tracepoint_##_provider##___##_name \ + __attribute__((section("__tracepoints"))) = \ + { \ + __tp_strtab_##_provider##___##_name, \ + 0, \ + NULL, \ + _TRACEPOINT_UNDEFINED_REF(_provider), \ + _TP_EXTRACT_STRING(_args), \ + }; \ + static struct tracepoint * __tracepoint_ptr_##_provider##___##_name \ + __attribute__((used, section("__tracepoints_ptrs"))) = \ + &__tracepoint_##_provider##___##_name; -extern -int tracepoint_register_lib(struct tracepoint * const *tracepoints_start, - int tracepoints_count); -extern -int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start); - -/* - * These weak symbols, the constructor, and destructor take care of - * registering only _one_ instance of the tracepoints per shared-ojbect - * (or for the whole main program). - */ extern struct tracepoint * const __start___tracepoints_ptrs[] - __attribute__((weak, visibility("hidden"))); + __attribute__((visibility("hidden"))); extern struct tracepoint * const __stop___tracepoints_ptrs[] - __attribute__((weak, visibility("hidden"))); + __attribute__((visibility("hidden"))); int __tracepoint_registered - __attribute__((weak, visibility("hidden"))); + __attribute__((visibility("hidden"))); +struct tracepoint_dlopen tracepoint_dlopen + __attribute__((visibility("hidden"))); static void __attribute__((constructor)) __tracepoints__init(void) { if (__tracepoint_registered++) return; - tracepoint_register_lib(__start___tracepoints_ptrs, + + tracepoint_dlopen.liblttngust_handle = + dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL); + if (!tracepoint_dlopen.liblttngust_handle) + return; + tracepoint_dlopen.tracepoint_register_lib = + URCU_FORCE_CAST(int (*)(struct tracepoint * const *, int), + dlsym(tracepoint_dlopen.liblttngust_handle, + "tracepoint_register_lib")); + tracepoint_dlopen.tracepoint_unregister_lib = + URCU_FORCE_CAST(int (*)(struct tracepoint * const *), + dlsym(tracepoint_dlopen.liblttngust_handle, + "tracepoint_unregister_lib")); +#ifndef _LGPL_SOURCE + tracepoint_dlopen.rcu_read_lock_sym_bp = + URCU_FORCE_CAST(void (*)(void), + dlsym(tracepoint_dlopen.liblttngust_handle, + "tp_rcu_read_lock_bp")); + tracepoint_dlopen.rcu_read_unlock_sym_bp = + URCU_FORCE_CAST(void (*)(void), + dlsym(tracepoint_dlopen.liblttngust_handle, + "tp_rcu_read_unlock_bp")); + tracepoint_dlopen.rcu_dereference_sym_bp = + URCU_FORCE_CAST(void *(*)(void *p), + dlsym(tracepoint_dlopen.liblttngust_handle, + "tp_rcu_dereference_sym_bp")); +#endif + tracepoint_dlopen.tracepoint_register_lib(__start___tracepoints_ptrs, __stop___tracepoints_ptrs - __start___tracepoints_ptrs); } static void __attribute__((destructor)) __tracepoints__destroy(void) { + int ret; + if (--__tracepoint_registered) return; - tracepoint_unregister_lib(__start___tracepoints_ptrs); + if (tracepoint_dlopen.tracepoint_unregister_lib) + tracepoint_dlopen.tracepoint_unregister_lib(__start___tracepoints_ptrs); + if (tracepoint_dlopen.liblttngust_handle) { + ret = dlclose(tracepoint_dlopen.liblttngust_handle); + assert(!ret); + memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen)); + } +} + +#else /* TRACEPOINT_DEFINE */ + +#define _DEFINE_TRACEPOINT(_provider, _name, _args) + +#endif /* #else TRACEPOINT_DEFINE */ + +#ifdef __cplusplus } +#endif + +#endif /* _LTTNG_TRACEPOINT_H */ + +/* The following declarations must be outside re-inclusion protection. */ #ifndef TRACEPOINT_EVENT + /* - * Usage of the TRACEPOINT_EVENT macro: + * How to use the TRACEPOINT_EVENT macro: * - * In short, an example: + * An example: + * + * TRACEPOINT_EVENT(someproject_component, event_name, * - * TRACEPOINT_EVENT(< [com_company_]project[_component] >, < event >, - * TP_PROTO(int arg0, void *arg1, char *string, size_t strlen, - * long *arg4, size_t arg4_len), - * TP_ARGS(arg0, arg1, string, strlen, arg4, arg4_len), - * TP_FIELDS( + * * TP_ARGS takes from 0 to 10 "type, field_name" pairs * + * + * TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen, + * long *, arg4, size_t, arg4_len), + * + * * TP_FIELDS describes the event payload layout in the trace * * + * TP_FIELDS( * * Integer, printed in base 10 * * ctf_integer(int, field_a, arg0) * @@ -230,12 +345,10 @@ static void __attribute__((destructor)) __tracepoints__destroy(void) * ) * ) * - * In more detail: - * - * We define a tracepoint, its arguments, and its 'fast binary record' - * layout. + * More detailed explanation: * - * Firstly, name your tracepoint via TRACEPOINT_EVENT(provider, name, + * The name of the tracepoint is expressed as a tuple with the provider + * and name arguments. * * The provider and name should be a proper C99 identifier. * The "provider" and "name" MUST follow these rules to ensure no @@ -275,152 +388,110 @@ static void __attribute__((destructor)) __tracepoints__destroy(void) * "event" is the name of the tracepoint event. * * the provider:event identifier is limited to 127 characters. - * - * As an example, let's consider a user-space application "someproject" - * that would have an internal thread scheduler: - * - * TRACEPOINT_EVENT(someproject_sched, switch, - * - * * - * * A function has a regular function arguments - * * prototype, declare it via TP_PROTO(): - * * - * - * TP_PROTO(struct rq *rq, struct task_struct *prev, - * struct task_struct *next), - * - * * - * * Define the call signature of the 'function'. - * * (Design sidenote: we use this instead of a - * * TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.) - * * - * - * TP_ARGS(rq, prev, next), - * - * * - * * Fast binary tracing: define the trace record via - * * TP_FIELDS(). You can think about it like a - * * regular C structure local variable definition. - * * - * * This is how the trace record is structured and will - * * be saved into the ring buffer. These are the fields - * * that will be exposed to readers. - * * - * * ctf_integer(pid_t, prev_pid, prev->pid) is equivalent - * * to a standard declaraton: - * * - * * pid_t prev_pid; - * * - * * followed by an assignment: - * * - * * prev_pid = prev->pid; - * * - * * ctf_array(char, prev_comm, prev->comm, TASK_COMM_LEN) is - * * equivalent to: - * * - * * char prev_comm[TASK_COMM_LEN]; - * * - * * followed by an assignment: - * * - * * memcpy(prev_comm, prev->comm, TASK_COMM_LEN); - * * - * - * TP_FIELDS( - * ctf_array(char, prev_comm, prev->comm, TASK_COMM_LEN) - * ctf_integer(pid_t, prev_pid, prev->pid) - * ctf_integer(int, prev_prio, prev->prio) - * ctf_array(char, next_comm, next->comm, TASK_COMM_LEN) - * ctf_integer(pid_t, next_pid, next->pid) - * ctf_integer(int, next_prio, next->prio) - * ) - * ) - * - * Do _NOT_ add comma (,) nor semicolon (;) after the TRACEPOINT_EVENT - * declaration. - * - * The TRACEPOINT_SYSTEM must be defined when declaring a - * TRACEPOINT_EVENT. See ust/tracepoint-event.h for information about - * usage of other macros controlling TRACEPOINT_EVENT. */ -#define TRACEPOINT_EVENT(provider, name, proto, args, fields) \ - _DECLARE_TRACEPOINT(provider, name, TP_PARAMS(proto), TP_PARAMS(args)) +#define TRACEPOINT_EVENT(provider, name, args, fields) \ + _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \ + _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args)) -#define TRACEPOINT_EVENT_CLASS(provider, name, proto, args, fields) -#define TRACEPOINT_EVENT_INSTANCE(provider, template, name, proto, args)\ - _DECLARE_TRACEPOINT(provider, name, TP_PARAMS(proto), TP_PARAMS(args)) +#define TRACEPOINT_EVENT_CLASS(provider, name, args, fields) -/* - * Declaration of tracepoints that take 0 argument. - */ -#define TRACEPOINT_EVENT_NOARGS(provider, name, fields) \ - _DECLARE_TRACEPOINT_NOARGS(provider, name) - -#define TRACEPOINT_EVENT_CLASS_NOARGS(provider, name, fields) -#define TRACEPOINT_EVENT_INSTANCE_NOARGS(provider, template, name) \ - _DECLARE_TRACEPOINT_NOARGS(provider, name) +#define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \ + _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \ + _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args)) #endif /* #ifndef TRACEPOINT_EVENT */ #ifndef TRACEPOINT_LOGLEVEL /* - * Tracepoint Loglevel Declaration Facility - * - * This is a place-holder the tracepoint loglevel declaration, - * overridden by the tracer implementation. + * Tracepoint Loglevels * * Typical use of these loglevels: * - * 1) Declare the mapping between loglevel names and an integer values - * within TRACEPOINT_LOGLEVEL_ENUM, using TP_LOGLEVEL for each tuple. - * Do _NOT_ add comma (,) nor semicolon (;) between the - * TRACEPOINT_LOGLEVEL_ENUM entries. Do _NOT_ add comma (,) nor - * semicolon (;) after the TRACEPOINT_LOGLEVEL_ENUM declaration. The - * name should be a proper C99 identifier. - * - * TRACEPOINT_LOGLEVEL_ENUM( - * TP_LOGLEVEL( < loglevel_name >, < value > ) - * TP_LOGLEVEL( < loglevel_name >, < value > ) - * ... - * ) - * - * e.g.: - * - * TRACEPOINT_LOGLEVEL_ENUM( - * TP_LOGLEVEL(LOG_EMERG, 0) - * TP_LOGLEVEL(LOG_ALERT, 1) - * TP_LOGLEVEL(LOG_CRIT, 2) - * TP_LOGLEVEL(LOG_ERR, 3) - * TP_LOGLEVEL(LOG_WARNING, 4) - * TP_LOGLEVEL(LOG_NOTICE, 5) - * TP_LOGLEVEL(LOG_INFO, 6) - * TP_LOGLEVEL(LOG_DEBUG, 7) - * ) - * - * 2) Then, declare tracepoint loglevels for tracepoints. A - * TRACEPOINT_EVENT should be declared prior to the the - * TRACEPOINT_LOGLEVEL for a given tracepoint name. The first field - * is the name of the tracepoint, the second field is the loglevel - * name. + * The loglevels go from 0 to 14. Higher numbers imply the most + * verbosity (higher event throughput expected. + * + * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels + * semantic. Loglevels 7 through 13 offer more fine-grained selection of + * debug information. + * + * TRACE_EMERG 0 + * system is unusable + * + * TRACE_ALERT 1 + * action must be taken immediately + * + * TRACE_CRIT 2 + * critical conditions + * + * TRACE_ERR 3 + * error conditions + * + * TRACE_WARNING 4 + * warning conditions + * + * TRACE_NOTICE 5 + * normal, but significant, condition + * + * TRACE_INFO 6 + * informational message + * + * TRACE_DEBUG_SYSTEM 7 + * debug information with system-level scope (set of programs) + * + * TRACE_DEBUG_PROGRAM 8 + * debug information with program-level scope (set of processes) + * + * TRACE_DEBUG_PROCESS 9 + * debug information with process-level scope (set of modules) + * + * TRACE_DEBUG_MODULE 10 + * debug information with module (executable/library) scope (set of units) + * + * TRACE_DEBUG_UNIT 11 + * debug information with compilation unit scope (set of functions) + * + * TRACE_DEBUG_FUNCTION 12 + * debug information with function-level scope + * + * TRACE_DEBUG_LINE 13 + * debug information with line-level scope (TRACEPOINT_EVENT default) + * + * TRACE_DEBUG 14 + * debug-level message (trace_printf default) + * + * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT + * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given + * tracepoint name. The first field is the provider name, the second + * field is the name of the tracepoint, the third field is the loglevel + * name. * * TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >, * < loglevel_name >) * - * The TRACEPOINT_SYSTEM must be defined when declaring a - * TRACEPOINT_LOGLEVEL_ENUM and TRACEPOINT_LOGLEVEL. The tracepoint - * loglevel enumeration apply to the entire TRACEPOINT_SYSTEM. Only one - * tracepoint loglevel enumeration should be declared per tracepoint - * system. + * The TRACEPOINT_PROVIDER must be already declared before declaring a + * TRACEPOINT_LOGLEVEL. */ -#define TRACEPOINT_LOGLEVEL_ENUM() -#define TRACEPOINT_LOGLEVEL(name, loglevel) - -#endif /* #ifndef TRACEPOINT_LOGLEVEL */ +enum { + TRACE_EMERG = 0, + TRACE_ALERT = 1, + TRACE_CRIT = 2, + TRACE_ERR = 3, + TRACE_WARNING = 4, + TRACE_NOTICE = 5, + TRACE_INFO = 6, + TRACE_DEBUG_SYSTEM = 7, + TRACE_DEBUG_PROGRAM = 8, + TRACE_DEBUG_PROCESS = 9, + TRACE_DEBUG_MODULE = 10, + TRACE_DEBUG_UNIT = 11, + TRACE_DEBUG_FUNCTION = 12, + TRACE_DEBUG_LINE = 13, + TRACE_DEBUG = 14, +}; -#ifdef __cplusplus -} -#endif +#define TRACEPOINT_LOGLEVEL(provider, name, loglevel) -#endif /* _UST_TRACEPOINT_H */ +#endif /* #ifndef TRACEPOINT_LOGLEVEL */