diff --git a/configure.ac b/configure.ac index 3ed7eabc72..bda9a34504 100755 --- a/configure.ac +++ b/configure.ac @@ -568,6 +568,8 @@ AC_ARG_ENABLE([zeromq], AS_HELP_STRING([--enable-zeromq], [enable ZeroMQ handler (libfrrzmq)])) AC_ARG_ENABLE([lttng], AS_HELP_STRING([--enable-lttng], [enable LTTng tracing])) +AC_ARG_ENABLE([usdt], + AS_HELP_STRING([--enable-usdt], [enable USDT probes])) AC_ARG_WITH([libpam], AS_HELP_STRING([--with-libpam], [use libpam for PAM support in vtysh])) AC_ARG_ENABLE([ospfapi], @@ -1865,6 +1867,18 @@ if test "$enable_lttng" = "yes"; then ]) fi +dnl ---- +dnl USDT +dnl ---- +if test "$enable_usdt" = "yes"; then + AC_CHECK_HEADERS([sys/sdt.h], [ + AC_DEFINE([HAVE_USDT], [1], [Enable USDT probes]) + USDT=true + ], [ + AC_MSG_ERROR([configuration specifies --enable-usdt but no USDT kernel headers (sys/sdt.h) found]) + ]) +fi + dnl ------ dnl ZeroMQ dnl ------ diff --git a/lib/subdir.am b/lib/subdir.am index 5c371f2cc9..ed3c30799d 100644 --- a/lib/subdir.am +++ b/lib/subdir.am @@ -253,6 +253,7 @@ pkginclude_HEADERS += \ lib/table.h \ lib/termtable.h \ lib/thread.h \ + lib/trace.h \ lib/typerb.h \ lib/typesafe.h \ lib/vector.h \ diff --git a/lib/trace.h b/lib/trace.h new file mode 100644 index 0000000000..73fc10a556 --- /dev/null +++ b/lib/trace.h @@ -0,0 +1,80 @@ +/* Tracing macros + * + * Wraps tracepoint macros for different tracing systems to allow switching + * between them at compile time. + * + * This should not be included directly by source files wishing to provide + * tracepoints. Instead, write a header that defines LTTng tracepoints and + * which includes this header, and include your new header in your source. USDT + * probes do not need tracepoint definitions, but are less capable than LTTng + * tracepoints. + * + * Copyright (C) 2020 NVIDIA Corporation + * Quentin Young + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + * This program 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 General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; see the file COPYING; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef _TRACE_H_ +#define _TRACE_H_ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif /* HAVE_CONFIG_H */ + +/* + * Provided here: + * - frrtrace(n, provider, name, ...args...) + * - frrtrace_enabled(provider, name) + * - frrtracelog(level, msg, ...) + * + * Use frrtrace() to define tracepoints. n is the number of arguments; this is + * needed because USDT probe definitions use DTRACE_PROBEn macros, so the + * number of args must be passed in order to expand the correct macro. + * + * frrtrace_enabled() maps to tracepoint_enabled() under LTTng and is always + * true when using USDT. In the future it could be mapped to USDT semaphores + * but this is not implemented at present. + * + * frrtracelog() maps to tracelog() under LTTng and should only be used in zlog + * core code, to propagate zlog messages to LTTng. It expands to nothing + * otherwise. + */ + +#if defined(HAVE_LTTNG) + +#define frrtrace(nargs, provider, name, ...) \ + tracepoint(provider, name, ## __VA_ARGS__) +#define frrtrace_enabled(...) tracepoint_enabled(__VA_ARGS__) +#define frrtracelog(...) tracelog(__VA_ARGS__) + +#elif defined(HAVE_USDT) + +#include "sys/sdt.h" + +#define frrtrace(nargs, provider, name, ...) \ + DTRACE_PROBE##nargs(provider, name, ## __VA_ARGS__) +#define frrtrace_enabled(...) true +#define frrtracelog(...) + +#else + +#define frrtrace(nargs, provider, name, ...) (void)0 +#define frrtrace_enabled(...) false +#define frrtracelog(...) (void)0 + +#endif + +#endif /* _TRACE_H_ */